ADESTO TECHNOLOGIES (IOTS) 10-Q 8 Nov 19 2019 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - $ / shares	9 Months Ended
	Sep. 30, 2019	Nov. 05, 2019
Document and Entity Information [Abstract]
Entity Central Index Key	0001395848
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2019
Document Transition Report	false
Entity File Number	001-37582
Entity Registrant Name	ADESTO TECHNOLOGIES CORPORATION
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	16-1755067
Entity Address, Address Line One	3600 Peterson Way
Entity Address, City or Town	Santa Clara
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	95054
City Area Code	408
Local Phone Number	400-0578
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
Entity Shell Company	false
Entity Listing, Par Value Per Share	$ 0.0001
Entity Common Stock, Shares Outstanding		30,260,296
Title of 12(b) Security	Class A common stock
Trading Symbol	IOTS
Security Exchange Name	NASDAQ
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q3
Amendment Flag	false

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 37,205	$ 8,630
Restricted cash	459	458
Accounts receivable, net	33,913	23,211
Inventories	16,343	18,635
Prepaid expenses	1,660	1,668
Other current assets	403	871
Total current assets	89,983	53,473
Property and equipment, net	8,040	7,085
Intangible assets, net	30,896	36,261
Operating lease right-of-use assets	4,474
Other non-current assets	2,300	1,729
Goodwill	38,640	38,640
Total assets	174,333	137,188
Current liabilities:
Accounts payable	20,778	16,146
Accrued compensation and benefits	4,359	4,038
Accrued expenses and other current liabilities	5,772	5,172
Price adjustments and other revenue reserves	5,108	4,819
Earn-out liability	10,130	10,450
Operating lease liabilities, current	1,186
Term loan, current		141
Total current liabilities	47,333	40,766
Term loan, non-current		29,418
Convertible senior notes, net	55,315
Operating lease liabilities, non-current	5,048
Deferred rent, non-current		1,947
Deferred tax liability, non-current	1,515	1,735
Other non-current liabilities	608	580
Total liabilities	109,819	74,446
Commitments and contingencies (See Note 10)
Stockholders’ equity:
Common stock, $0.0001 par value, 100,000,000 shares authorized; 30,119,051 and 29,442,065 shares issued and outstanding as of September 30, 2019 and December 31, 2018, respectively	3	3
Additional paid-in capital	205,003	184,158
Accumulated other comprehensive loss	(518)	(135)
Accumulated deficit	(139,974)	(121,284)
Total stockholders’ equity	64,514	62,742
Total liabilities and stockholders’ equity	$ 174,333	$ 137,188

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Sep. 30, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized (in shares)	5,000,000	5,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, shares issued (in shares)	30,119,051	29,442,065
Common stock, shares outstanding (in shares)	30,119,051	29,442,065

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Statement [Abstract]
Revenue, net	$ 32,028	$ 21,927	$ 90,297	$ 55,412
Cost of revenue	15,781	12,344	46,384	30,885
Gross profit	16,247	9,583	43,913	24,527
Operating expenses:
Research and development	7,384	5,297	22,353	13,139
Selling, general and administrative	8,461	5,795	24,554	14,762
Amortization of intangible assets	1,789	1,138	5,365	2,119
Acquisition related expenses		4,776	227	6,793
Restructuring and other charges			1,694
Total operating expenses	17,634	17,006	54,193	36,813
Loss from operations	(1,387)	(7,423)	(10,280)	(12,286)
Other income (expense):
Interest expense, net	(6,034)	(1,046)	(8,781)	(2,368)
Other income, net	190	8	359	17
Total other income (expense), net	(5,844)	(1,038)	(8,422)	(2,351)
Loss before benefit from income taxes	(7,231)	(8,461)	(18,702)	(14,637)
Provision for (benefit from) income taxes	337	(64)	236	(80)
Net loss	$ (7,568)	$ (8,397)	$ (18,938)	$ (14,557)
Net loss per share:
Basic and diluted (in dollars per share)	$ (0.25)	$ (0.30)	$ (0.64)	$ (0.61)
Weighted average number of shares used in computing net loss per share:
Basic and diluted (in shares)	30,016,585	28,171,952	29,784,314	23,717,727

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement of Comprehensive Income [Abstract]
Net loss	$ (7,568)	$ (8,397)	$ (18,938)	$ (14,557)
Other comprehensive loss, net of tax:
Foreign currency translation adjustment	(299)	(148)	(383)	(65)
Comprehensive loss	$ (7,867)	$ (8,545)	$ (19,321)	$ (14,622)

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY - USD ($) $ in Thousands	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Loss [Member]	Accumulated Deficit [Member]	Total
Beginning balance at Dec. 31, 2017	$ 2	$ 133,087	$ (295)	$ (99,844)	$ 32,950
Beginning balance (in shares) at Dec. 31, 2017	21,291,833
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of warrants		4,799			4,799
Options exercised		106			106
Options exercised (in shares)	47,405
Employee stock purchase plan		223			223
Employee stock purchase plan (in shares)	55,806
Restricted stock units, net of taxes paid related to net settlement of equity awards		(55)			(55)
Restricted stock units, net of taxes paid related to net settlement of equity awards (in shares)	14,248
Stock-based compensation		443			443
Foreign currency translation adjustment			(17)		(17)
Net loss				(1,102)	(1,102)
Ending balance at Mar. 31, 2018	$ 2	138,603	(312)	(100,946)	37,347
Ending balance (in shares) at Mar. 31, 2018	21,409,292
Beginning balance at Dec. 31, 2017	$ 2	133,087	(295)	(99,844)	32,950
Beginning balance (in shares) at Dec. 31, 2017	21,291,833
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Foreign currency translation adjustment					(65)
Net loss					(14,557)
Ending balance at Sep. 30, 2018	$ 3	183,087	(360)	(114,401)	68,329
Ending balance (in shares) at Sep. 30, 2018	29,367,787
Beginning balance at Dec. 31, 2017	$ 2	133,087	(295)	(99,844)	$ 32,950
Beginning balance (in shares) at Dec. 31, 2017	21,291,833
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Options exercised (in shares)					112,965
Ending balance at Dec. 31, 2018	$ 3	184,158	(135)	(121,284)	$ 62,742
Ending balance (in shares) at Dec. 31, 2018	29,442,065				29,442,065
Beginning balance at Mar. 31, 2018	$ 2	138,603	(312)	(100,946)	$ 37,347
Beginning balance (in shares) at Mar. 31, 2018	21,409,292
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Options exercised		114			114
Options exercised (in shares)	38,345
Restricted stock units, net of taxes paid related to net settlement of equity awards		(162)			(162)
Restricted stock units, net of taxes paid related to net settlement of equity awards (in shares)	75,388
Stock-based compensation		720			720
Foreign currency translation adjustment			100		100
Net loss				(5,058)	(5,058)
Ending balance at Jun. 30, 2018	$ 2	139,275	(212)	(106,004)	33,061
Ending balance (in shares) at Jun. 30, 2018	21,523,025
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of 7,705,000 shares of common stock @ $6.00 (net of issuance costs of $3.1 million)	$ 1	42,662			42,663
Issuance of 7,705,000 shares of common stock @ $6.00 (net of issuance costs of $3.1 million) ( in shares)	7,705,000
Options exercised		43			43
Options exercised (in shares)	22,472
Employee stock purchase plan		327			327
Employee stock purchase plan (in shares)	69,761
Restricted stock units, net of taxes paid related to net settlement of equity awards		(160)			(160)
Restricted stock units, net of taxes paid related to net settlement of equity awards (in shares)	47,529
Stock-based compensation		940			940
Foreign currency translation adjustment			(148)		(148)
Net loss				(8,397)	(8,397)
Ending balance at Sep. 30, 2018	$ 3	183,087	(360)	(114,401)	68,329
Ending balance (in shares) at Sep. 30, 2018	29,367,787
Beginning balance at Dec. 31, 2018	$ 3	184,158	(135)	(121,284)	$ 62,742
Beginning balance (in shares) at Dec. 31, 2018	29,442,065				29,442,065
Increase (Decrease) in Stockholders' Equity [Roll Forward]
ASC 842 adoption adjustment				248	$ 248
Options exercised		26			26
Options exercised (in shares)	9,712
Employee stock purchase plan		544			544
Employee stock purchase plan (in shares)	129,815
Restricted stock units, net of taxes paid related to net settlement of equity awards		(85)			(85)
Restricted stock units, net of taxes paid related to net settlement of equity awards (in shares)	66,995
Stock-based compensation		1,075			1,075
Foreign currency translation adjustment			(128)		(128)
Net loss				(7,060)	(7,060)
Ending balance at Mar. 31, 2019	$ 3	185,718	(263)	(128,096)	57,362
Ending balance (in shares) at Mar. 31, 2019	29,648,587
Beginning balance at Dec. 31, 2018	$ 3	184,158	(135)	(121,284)	$ 62,742
Beginning balance (in shares) at Dec. 31, 2018	29,442,065				29,442,065
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Options exercised (in shares)					91,173
Foreign currency translation adjustment					$ (383)
Net loss					(18,938)
Ending balance at Sep. 30, 2019	$ 3	205,003	(518)	(139,974)	$ 64,514
Ending balance (in shares) at Sep. 30, 2019	30,119,051				30,119,051
Beginning balance at Mar. 31, 2019	$ 3	185,718	(263)	(128,096)	$ 57,362
Beginning balance (in shares) at Mar. 31, 2019	29,648,587
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Options exercised		127			127
Options exercised (in shares)	53,275
Restricted stock units, net of taxes paid related to net settlement of equity awards		(53)			(53)
Restricted stock units, net of taxes paid related to net settlement of equity awards (in shares)	85,448
Stock-based compensation		1,364			1,364
Foreign currency translation adjustment			44		44
Net loss				(4,310)	(4,310)
Ending balance at Jun. 30, 2019	$ 3	187,156	(219)	(132,406)	54,534
Ending balance (in shares) at Jun. 30, 2019	29,787,310
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Options exercised		135			135
Options exercised (in shares)	28,186
Employee stock purchase plan		649			649
Employee stock purchase plan (in shares)	154,116
Restricted stock units, net of taxes paid related to net settlement of equity awards		(84)			(84)
Restricted stock units, net of taxes paid related to net settlement of equity awards (in shares)	149,439
Stock-based compensation		1,635			1,635
Foreign currency translation adjustment			(299)		(299)
Purchase of capped calls		(6,150)			(6,150)
Equity component of convertible senior notes (net of issuance costs of $1 million)		21,662			21,662
Net loss				(7,568)	(7,568)
Ending balance at Sep. 30, 2019	$ 3	$ 205,003	$ (518)	$ (139,974)	$ 64,514
Ending balance (in shares) at Sep. 30, 2019	30,119,051				30,119,051

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY (Parenthetical) $ in Thousands	3 Months Ended
	Sep. 30, 2018USD ($)$ / shares
Statement of Stockholders' Equity [Abstract]
Stock issuance costs | $	$ 3,100
Issue price (per share) | $ / shares	$ 6

CONDENSED CONSOLIDATED STATEM_5

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Cash flows from operating activities:
Net loss	$ (18,938)	$ (14,557)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	4,074	2,103
Depreciation and amortization	2,226	1,687
Amortization of intangible assets	5,365	2,119
Amortization of debt discount and issuance costs	5,149	707
Prepayment premium and related costs	784
Deferred income taxes	(220)	(463)
Gain on investment		(1)
Gain on sale of equipment		(18)
Decrease in fair value of earn-out liability	(320)
Changes in assets and liabilities:
Accounts receivable	(10,702)	(12,826)
Inventories	2,292	(6,017)
Prepaid expenses and other current assets	475	949
Other non-current assets	179	(8)
Accounts payable	3,712	5,834
Accrued compensation and benefits	321	1,087
Accrued expenses and other current liabilities	1,057	1,178
Price adjustments and other revenue reserves	289	5,202
Other non-current liabilities	(771)	283
Deferred rent		(341)
Net cash used in operating activities	(5,028)	(13,082)
Cash flows from investing activities:
Acquisition of property and equipment	(2,518)	(2,631)
Investment in unconsolidated affiliate	(346)	(434)
Net cash used in investing activities	(2,864)	(66,517)
Cash flows from financing activities:
Proceeds from public offering, net of underwriting discounts and commissions		42,658
Proceeds from exercise of stock options and employee stock purchase plan	1,481	813
Tax withholdings related to net share settlement of restricted stock units	(222)	(372)
Payment of debt issuance costs	(15)
Payments on revolving line of credit		(1,500)
Proceeds from issuance of convertible senior notes, net of issuance costs	77,280	33,591
Payments on term loan	(35,492)	(12,000)
Purchase of capped calls	(6,150)
Net cash provided by financing activities	36,882	63,190
Effect of exchange rates on cash, cash equivalents and restricted cash	(414)	(396)
Net increase (decrease) in cash, cash equivalents and restricted cash	28,576	(16,805)
Cash, cash equivalents and restricted cash - beginning of year	9,088	30,078
Cash, cash equivalents and restricted cash - end of period	37,664	13,273
Supplemental disclosures of other cash flow information:
Cash paid for interest expense	2,882	1,777
Supplemental disclosures of non-cash investing and financing information:
Purchase of property and equipment included in accounts payable	$ 632	159
Fair value of warrants issued in connection with term loan		4,799
Echelon Corporation [Member]
Cash flows from investing activities:
payments to acquire businesses, net of cash acquired		(28,836)
S3 Asic Semiconductors Limited [Member]
Cash flows from investing activities:
payments to acquire businesses, net of cash acquired		$ (34,616)

Organization and Summary of Sig

Organization and Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Summary of Significant Accounting Policies	Note 1. Organization and Summary of Significant Accounting Policies. Organization and Nature of Operations. Adesto Technologies Corporation (together with its subsidiaries; “Adesto”, “we”, “our”, “us” or the “Company”) was incorporated in the state of California in January 2006 and reincorporated in Delaware in October 2015. We are a leading provider of innovative, application-specific semiconductors and systems for the Internet of Things era. Our corporate headquarters are located in Santa Clara, California. On May 9, 2018 we acquired 100% of the issued capital of S3 Asic Semiconductors Limited and on September 14, 2018 we acquired 100% of the issued capital of Echelon Corporation. Our financial results include the operating results of those entities from the date of acquisition. Basis of Presentation. The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) for interim financial information and with the instructions to Form 10‑Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by U.S. GAAP to complete annual consolidated financial statements. In the opinion of our management, all adjustments (consisting of normal recurring adjustments) considered necessary to present fairly the financial position of the Company and its results of operations and cash flows for the interim periods presented have been included. Operating results for the nine months ended September 30, 2019 are not necessarily indicative of the results that may be expected for the year ending December 31, 2019, for any other interim period or for any other future year. The condensed consolidated balance sheet as of December 31, 2018 was derived from the audited consolidated financial statements as of that date, but does not include all of the disclosures required by U.S. GAAP. The accompanying condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto contained in the Company’s Annual Report on Form 10‑K for the year ended December 31, 2018, filed with the Securities and Exchange Commission on March 18, 2019. The condensed consolidated financial statements include the results of our operations, and the operations of our wholly owned subsidiaries. All intercompany balances and transactions have been eliminated. There have been no material changes to our significant accounting policies described in Note 1, Organization and Summary of Significant Accounting Policies, in Notes to Consolidated Financial Statements in Item 8 of Part II of our Annual Report on Form 10‑K for the year ended December 31, 2018 that have had a material impact on our condensed consolidated financial statements and related notes, except as described below. Recent Accounting Pronouncements. In August 2018, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2018-13, Fair Value Measurement Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement. As part of the FASB's disclosure framework project, it has eliminated, amended and added disclosure requirements for fair value measurements. Entities will no longer be required to disclose the amount of, and reasons for, transfers between Level 1 and Level 2 of the fair value hierarchy, the policy of timing of transfers between levels of the fair value hierarchy and the valuation processes for Level 3 fair value measurements. Public companies will be required to disclose the range and weighted average used to develop significant unobservable inputs for Level 3 fair value measurements. This ASU is effective for public entities for annual and interim periods beginning after December 15, 2019. Early adoption is permitted as of the beginning of any interim or annual reporting period. This ASU will have an impact on the Company's disclosures. In January 2017, the FASB issued ASU No. 2017-04, Intangibles—Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment. This ASU eliminates Step 2 from the goodwill impairment test. Instead, an entity should recognize an impairment charge for the amount by which the carrying value exceeds the reporting unit’s fair value, not to exceed the total amount of goodwill allocated to that reporting unit. This ASU is effective for annual or any interim goodwill impairment tests in fiscal years beginning after December 15, 2019. The Company is currently evaluating the effect of the adoption of this ASU, but anticipates that the adoption will not have a material impact on its consolidated financial statements. In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. This ASU requires instruments measured at amortized cost to be presented at the net amount expected to be collected. Entities are also required to record allowances for available-for-sale debt securities rather than reduce the carrying amount. This ASU is effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. The Company expects that the adoption will not have a material impact on its consolidated financial statements. Recently Adopted Accounting Pronouncements. Adoption of ASC 842: We adopted ASU No. 2016-02, Leases (“Topic 842”), as of January 1, 2019, using the modified retrospective approach. The modified retrospective approach provides a method for recording existing leases at the beginning of the period of adoption. In addition, we elected the package of practical expedients permitted under the transition guidance within the new standard, which among other things, allowed us to carry forward the historical lease classification and we elected the hindsight practical expedient to determine the lease term for existing leases. We determined that most renewal options would not be reasonably certain in determining the expected lease term. The comparative information has not been restated and continues to be reported under the accounting standards in effect for those periods. Adoption of the new standard resulted in the recording of right of use assets of $4.9 million and lease liabilities of $7.0 million and eliminating deferred rent of $2.4 million, as of January 1, 2019. The standard did not have an impact on our consolidated results of operations or cash flows. The effect of the changes made to our consolidated January 1, 2019 balance sheet for the adoption of the new lease standard was as follows (in thousands): Balance as of Adjustments Balance as of December 31, Due to January 1, 2018 ASC 842 2019 Operating lease right-of-use assets $ — $ 4,877 $ 4,877 Total assets $ 137,188 $ 4,877 $ 142,065 Operating lease liabilities, current $ — $ 1,116 $ 1,116 Operating lease liabilities, non-current $ — $ 5,917 $ 5,917 Deferred rent $ 2,404 (2,404) — Total liabilities $ 74,446 $ 4,629 $ 79,075 Accumulated deficit $ (121,284) $ 248 $ (121,036) Total stockholders' equity $ 62,742 $ 248 $ 62,990 Total liabilities and stockholders' equity $ 137,188 $ 4,877 $ 142,065 Revenue Recognition. Revenue is recognized when control of the promised goods or services is transferred to customers, in an amount that reflects the consideration we expect to be entitled to in exchange for those goods or services. Sales of products with alternative use account for the majority of our revenue and are recognized at a point in time, the timing of such recognition remained the same under Topic 606. Taxes assessed by a governmental authority that are both imposed on and concurrent with a specific revenue-producing transaction, that are collected by us from a customer and deposited with the relevant government authority, are excluded from revenue. Our revenue arrangements do not contain significant financing components. Revenue is recognized over a period of time when it is assessed that performance obligations are satisfied over a period rather than at a point in time. When any of the following criteria is fulfilled, revenue is recognized over a period of time: (a) The customer simultaneously receives and consumes the benefits provided by the performance as Adesto performs. (b) Adesto’s performance creates or enhances an asset (for example, work in process) that the customer controls as the asset is created or enhanced. (c) Adesto’s performance does not create an asset with an alternative use, and Adesto has an enforceable right to payment for performance completed to date. If revenue is recognized over a period of time, we would then select an appropriate method for measuring progress toward complete satisfaction of the performance obligation, usually costs incurred to date relative to the total expected costs to the satisfaction of that performance obligation. Typically, our revenue is recognized at a point in time. Sales to certain distributors are made under arrangements which provide the distributors with price adjustments, price protection, stock rotation and other allowances under certain circumstances. These adjustments and allowances are accounted for as variable consideration. We estimate these amounts based on the expected amount to be provided to customers and reduce revenue recognized. We believe that there will not be significant changes to our estimates of variable consideration. If a customer pays consideration, or Adesto has a right to an amount of consideration that is unconditional before we transfer a good or service to the customer, those amounts are classified as deferred income/ advances received from customers which are included in other current liabilities or other long-term liabilities when the payment is made or it is due, whichever is earlier. If the arrangement includes variable contingent consideration, we recognize revenue over time if we can reasonably measure its progress, or we are capable of providing reliable information that would be required to apply an appropriate method of measuring progress. To date, we have not had any arrangements incorporating contingent consideration. Sales commissions are owed and are recorded at the time of sell through of our products to end customers. These costs are recorded within selling, general and administrative expenses. The Company has entered into, and will continue to enter into, development agreements. Typically, revenue is recognized over time on a percentage of completion basis based on resources expended to date as compared to budgeted resources. Cost associated with these contracts can be classified as cost of revenue or research and development expense depending on the terms of the contract. We do not disclose the value of unsatisfied performance obligations for (i) contracts with an original expected length of one year or less and (ii) contracts for which we recognize revenue at the amount to which we have the right to invoice for services performed. Timing of Revenue Recognition. Three Months Ended Nine Months Ended September 30, September 30, 2019 2018 2019 2018 (in thousands) Products transferred at a point in time $ 26,023 $ 18,250 $ 76,480 $ 49,748 Products and services transferred over time 6,005 3,677 13,817 5,664 $ 32,028 $ 21,927 $ 90,297 $ 55,412 The following table reflects the changes in our contract assets, which we classify as accounts receivable, unbilled and our contract liabilities which we classify as deferred revenue: September 30, December 31, 2019 2018 Change (in thousands) Contract assets: Accounts receivable, unbilled $ 3,863 $ 751 $ 3,112 Contract liabilities: Deferred revenue $ 649 $ 1,848 $ (1,199) Accounts receivable, unbilled represents revenue recognized on certain development contracts for which invoicing has not yet occurred based on the terms of the development contract. As of September 30, 2019 and December 31, 2018, we had $3.9 million and $0.8 million, respectively, classified as unbilled accounts receivable within accounts receivable. Deferred revenue represents amounts invoiced to customers for certain development contracts for which revenue has yet to be recognized based on actual development hours performed. Typically, the timing of invoicing is based on the terms of the contract. As of September 30, 2019 and December 31, 2018, we had $0.6 million and $1.8 million, respectively, of deferred revenue classified as accrued expenses and other current liabilities. Reclassifications. Certain reclassifications have been made to prior periods’ condensed consolidated financial statements to conform to the current period presentation. These reclassifications did not result in any change in previously reported total assets, stockholders’ equity or net loss. Use of Estimates. The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates, judgments and assumptions that affect the reported amount of assets, liabilities, revenue and expenses and related disclosures of contingent assets and liabilities. On an on-going basis, we evaluate those estimates, including those related to allowances for doubtful accounts, price adjustments and other revenue reserves, warranty accrual, inventory write-downs, valuation of long-lived assets, including property and equipment and identifiable intangible assets and goodwill, loss on purchase commitments, valuation of deferred taxes and contingencies. In addition, we use assumptions when employing the Black-Scholes option-pricing model to calculate the fair value of stock options granted and Monte Carlo simulation techniques to value certain restricted stock units with market-based vesting conditions. We base our estimates of the carrying value of certain assets and liabilities on historical experience and on various other assumptions that are believed to be reasonable under the circumstances, when these carrying values are not readily available from other sources. Actual results could differ from these estimates. Product Warranty. Our non-volatile memory (“NVM”) products are sold with a limited warranty for a period of one year, warranting that the product conforms to specifications and is free from material defects in design, materials and workmanship. To date, we have had insignificant returns of any defective production parts. During 2018 and the nine months ended September 30, 2019, we did not record any additional liability related to potential warranty claims. As of September 30, 2019 and December 31, 2018, the warranty accrual related to NVM products was $51,000 and is included in accrued expenses and other current liabilities on the condensed consolidated balance sheets. At the time of the Echelon acquisition we recorded a warranty liability of $401,000 related to Echelon products. During 2018 and the nine months ended September 30, 2019, the warranty liability increased by $53,000 and decreased by $1,000, res pectively . As of September 30, 2019 and December 31, 2018, the warranty accrual related to Echelon products was $453,000 and $454,000, respectively, and is included in accrued expenses and other current liabilities on the condensed consolidated balance sheets. Foreign Currency Translation. The functional currency of our foreign subsidiaries is the local currency. In consolidation, we translate assets and liabilities at exchange rates in effect at the consolidated balance sheet date. We translate revenue and expense accounts at the average exchange rates during the period in which the transaction takes place. Net gains and losses from foreign currency translation of assets and liabilities were losses of $299,000 and $148,000 for the three months ended September 30, 2019 and 2018, respectively, and $383,000 and $65,000 for the nine months ended September 30, 2019 and 2018, respectively, and are included in the cumulative translation adjustment component of accumulated other comprehensive loss, net of tax, a component of stockholders’ equity. Net gains and losses arising from transactions denominated in currencies other than the functional currency were gains of $181,000 and $9,000 for the three months ended September 30, 2019 and 2018, respectively, and a gain of $31,000 and a loss of $1,000 for the nine months ended September 30, 2019 and 2018, respectively, and are included in other income, net in the condensed consolidated statements of operations. Concentration of Risk. Our products are primarily manufactured, assembled and tested by third-party foundries and other contractors in Asia and we are heavily dependent on a single foundry in Taiwan for the manufacture of wafers and a single contractor in the Philippines for assembly and testing of our products. We do not have long-term agreements with either of these suppliers. A significant disruption in the operations of these parties would adversely impact the production of our products for a substantial period of time, which could have a material adverse effect on our business, financial condition, operating results and cash flows. Financial instruments that potentially subject us to significant concentrations of credit risk consist principally of cash and cash equivalents, investments and accounts receivables. We place substantially all of our cash and cash equivalents and investments on deposit with a reputable, high credit quality financial institution in the United States of America. We believe that the bank that holds substantially all of our cash and cash equivalents and investments is financially sound and, accordingly, subject to minimal credit risk. Deposits held with the bank may exceed the amount of insurance provided on such deposits. We generally do not require collateral or other security in support of accounts receivable. We periodically review the need for an allowance for doubtful accounts by considering factors such as historical experience, credit quality, the age of the accounts receivable balances and current economic conditions that may affect a customer’s ability to pay. The allowance for doubtful accounts as of September 30, 2019 and December 31, 2018 was $60,000 and $30,000, respectively. Customer concentrations as a percentage of revenue, net were as follows: Three Months Ended Nine Months Ended September 30, September 30, 2019 2018 2019 2018 Customer A * 20 % 17 % 21 % Customer B 23 % * 12 % * * Customer concentrations as a percentage of gross accounts receivable were as follows: September 30, December 31, 2019 2018 Customer B 28 % 13 %

Acquisitions

Acquisitions	9 Months Ended
	Sep. 30, 2019
Business Combinations [Abstract]
Acquisition	Note 2. Acquisitions. Echelon Corporation On September 14, 2018, we acquired 100% of the issued capital of Echelon Corporation, a Delaware corporation (“Echelon”), pursuant to the terms of an Agreement and Plan of Merger dated as of June 28, 2018. The purchase price was approximately $44.1 million paid in cash. The assets and liabilities of Echelon were recorded in our condensed consolidated balance sheet as of the acquisition date, at their respective fair values. Fair value is estimated based on one or a combination of income, cost and/or market approaches, as determined based on the nature of the asset or liability, and the level of inputs available. With respect to assets and liabilities, the determination of fair value requires management to make subjective judgments as to projections of future operating performance, the appropriate discount rate to apply, long-term growth rates, and other factors, which affect the amounts recorded in the purchase price allocation. The excess of the consideration transferred over the fair value of the identifiable assets, net of liabilities, is recorded as goodwill, which is indicative of the expected continued growth and development of Echelon. The purchase price allocation that follows is based on these estimated fair values of assets acquired and liabilities assumed. We will continue to evaluate certain assets, liabilities and tax estimates that are subject to change within the measurement period (up to one year from the acquisition date). The following table summarizes the fair values of assets acquired and liabilities assumed (in thousands): Cash $ 15,270 Short term investments 1,274 Accounts receivable 3,020 Inventories 5,710 Other current assets 2,845 Property and equipment, net 614 Intangible assets 17,690 Goodwill 4,266 Other non-current assets 252 Accounts payable (3,630) Other current liabilities (2,642) Other non-current liabilities (563) Fair value of net assets acquired $ 44,106 Intangible assets reflect the following: Fair Value Useful (in thousands) Customer relationships $ 6,520 7 Developed technology 10,670 4 Trademarks 500 8 Total acquired intangible assets $ 17,690 S3 Asic Semiconductors Limited On May 9, 2018, we acquired 100% of the issued capital of S3 Asic Semiconductors Limited, a private company limited by shares and incorporated in Ireland (“S3”), pursuant to the Share Purchase Agreement dated May 9, 2018 (the “Agreement”). S3 is headquartered in Ireland and its subsidiaries are in the United States, Portugal and the Czech Republic. S3 and its subsidiaries are engaged in the business of providing advanced mixed signal semiconductor devices and intellectual property to customers in the industrial and communications markets. The aggregate consideration was approximately $35.0 million in cash and contingent consideration in the form of a $15.0 million earn-out. The earn-out is based on achievement of certain milestones through 2019, including minimum total revenue targets, revenue derived from sales of semiconductor devices and new customer engagements with minimum value thresholds. The assets and liabilities of S3 were recorded in our condensed consolidated balance sheet as of the acquisition date, at their respective fair values. Fair value is estimated based on one or a combination of income, cost and/or market approaches, as determined based on the nature of the asset or liability, and the level of inputs available. With respect to assets and liabilities, the determination of fair value requires management to make subjective judgments as to projections of future operating performance, the appropriate discount rate to apply, long-term growth rates, and other factors, which affect the amounts recorded in the purchase price allocation. The excess of the consideration transferred over the fair value of the identifiable assets, net of liabilities, is recorded as goodwill, which is indicative of the expected continued growth and development of S3. The purchase price allocation that follows is based on these estimated fair values of assets acquired and liabilities assumed. We will continue to evaluate certain assets, liabilities and tax estimates that are subject to change within the measurement period (up to one year from the acquisition date). The following table summarizes the fair values of assets acquired and liabilities assumed (in thousands): Cash $ 267 Accounts receivable 192 Other current assets 883 Property and equipment, net 191 Intangible assets 15,340 Goodwill 34,352 Accounts payable (37) Deferred revenue (129) Earn-out liability, current (10,218) Other current liabilities (761) Deferred tax liability (1,918) Earn-out liability, non-current (3,279) Fair value of net assets acquired $ 34,883 Intangible assets reflect the following: Fair Value Useful (in thousands) Customer relationships $ 12,880 7 Contract backlog 210 0.5 Developed technology 1,080 5 Non-compete agreements 380 2 Trademarks 790 12 Total $ 15,340

Balance Sheet Components

Balance Sheet Components	9 Months Ended
	Sep. 30, 2019
Balance Sheet Related Disclosures [Abstract]
Balance Sheet Components	Note 3. Balance Sheet Components. Accounts Receivable, Net. Accounts receivable, net consisted of the following (in thousands): September 30, December 31, 2019 2018 Accounts receivable $ 30,110 $ 22,490 Accounts receivable, unbilled 3,863 751 Allowance for doubtful accounts (60) (30) Total accounts receivable, net $ 33,913 $ 23,211 Inventories. Inventories consisted of the following (in thousands): September 30, December 31, 2019 2018 Raw materials $ 2,213 $ 1,427 Work-in-process 8,019 11,451 Finished goods 6,111 5,757 Total inventories $ 16,343 $ 18,635 For the three months ended September 30, 2019, we recorded a benefit of $0.3 million related to excess inventory. For the three months ended September 30, 2018, we recorded a write-down of $16,000 related to excess inventory. For the nine months ended September 30, 2019, we recorded a write-down of $0.3 million related to excess inventory. For the nine months ended September 30, 2018, we realized a benefit of $0.9 million from the sales of previously reserved products. Inventory write-downs are primarily associated with products built in excess of customer demand which resulted in excess inventory levels, legacy products for which no demand exists, lower of cost or net realizable value write-downs associated with products for which costs exceeded net realizable value, and write-downs associated with the closing of the Echelon lighting business. Property and Equipment, Net. Property and equipment, net consisted of the following (in thousands): September 30, December 31, 2019 2018 Machinery and equipment $ 17,136 $ 15,537 Leasehold improvements 4,418 4,422 Computer software 4,328 3,760 Furniture and fixtures 934 372 Construction in progress 115 52 Property and equipment, at cost 26,931 24,143 Accumulated depreciation and amortization (18,891) (17,058) Property and equipment, net $ 8,040 $ 7,085 The Company incurs costs for the fabrication of masks used by its foundry partners to manufacture its products. Beginning the first fiscal quarter of 2017, the Company capitalizes mask costs that are expected to be utilized in production manufacturing as the Company’s product development process has become more predictable and thus supports capitalization of the mask. The capitalized mask costs begin depreciating to cost of revenue once the products go into production. Depreciation is computed using the straight-line method over a three- year period which is the expected useful life of the mask. Previously mask sets were expensed to research and development. Depreciation and amortization expense of property and equipment for the three and nine months ended September 30, 2019 was $ 0.9 million and $2.2 million, respectively. Depreciation and amortization expense of property and equipment for the three and nine months ended September 30, 2018 was $0.6 million and $1.7 million, respectively. Accrued Expenses and Other Current Liabilities. Accrued expenses and other current liabilities consisted of the following (in thousands): September 30, December 31, 2019 2018 Accrued sales commission payable $ 260 $ 387 Accrued manufacturing expenses 1,023 692 Liabilities to certain customers — 366 Warranty reserve 504 505 Lighting disposal liabilities 1,404 — Deferred revenue, current portion 649 1,848 Other accrued liabilities 1,932 1,374 Total accrued expenses and other current liabilities $ 5,772 $ 5,172

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2019
Fair Value Disclosures [Abstract]
Fair Value Measurements	Note 4. Fair Value Measurements. Fair value is defined as the exchange price that would be received from selling an asset or paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. We measure financial assets and liabilities at fair value at each reporting period using a fair value hierarchy which requires us to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. A financial instrument’s classification within the fair value hierarchy is based upon the lowest level of input that is significant to the fair value measurement. Three levels of inputs may be used to measure fair value: Level 1. Quoted prices in active markets for identical assets or liabilities. Level 2. Quoted prices for similar assets and liabilities in active markets or inputs other than quoted prices which are observable for the assets or liabilities, either directly or indirectly through market corroboration, for substantially the full term of the financial instruments. Level 3. Unobservable inputs which are supported by little or no market activity and which are significant to the fair value of the assets or liabilities. Financial assets measured at fair value on a recurring basis were as follows: Fair Value Measurement at Reporting Date Using Significant Quoted Prices in Other Significant Active Markets Observable Unobservable for Identical Inputs Inputs Assets (Level 1) (Level 2) (Level 3) Total (in thousands) As of September 30, 2019 Assets: Money market funds $ 460 $ — $ — $ 460 U.S. government securities 300 — — 300 $ 760 $ — $ — $ 760 Liabilities: Earn-out liability $ — $ — $ 10,130 $ 10,130 As of December 31, 2018 Assets: Money market funds $ 458 $ — $ — $ 458 U.S. government securities 1,282 — — 1,282 $ 1,740 $ — $ — $ 1,740 Liabilities: Earn-out liability $ — $ — $ 10,450 $ 10,450 As of September 30, 2019, we had an earn-out liability of $10.1 million, all of which related to the acquisition of S3 Semiconductors, which was completed in May 2018 (see Note 2). The earn-out liability was calculated using the present value of a probability weighted income approach. Changes in the earn-out liability during 2019 was as follows (in thousands): Balance as of January 1, 2019 $ 10,450 Acquisitions — Change in fair value (320) Change in foreign currency exchange rate — Balance as of September 30, 2019 $ 10,130 The Company’s cash equivalents include U.S. government securities with a minimum and weighted average credit rating of A-1+. The Company values these securities based on pricing from pricing vendors, who may use quoted prices in active markets for identical assets (Level 1 inputs) or inputs other than quoted prices that are observable either directly or indirectly (Level 2 inputs) in determining fair value. As of September 30, 2019, the Company classified all of its fixed income securities as having Level 1 inputs. The Company's procedures include controls to ensure that appropriate fair values are recorded by comparing prices obtained from a third party independent source .

Intangible Assets, net

Intangible Assets, net	9 Months Ended
	Sep. 30, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets, net	Note 5. Intangible Assets, net. In 2012, in connection with our purchase of the serial flash memory product line assets from Atmel Corporation, we recorded $16.4 million of intangible assets. In connection with the acquisition of S3 (Note 2), we recorded $15.3 million of intangible assets. In connection with the acquisition of Echelon (Note 2), we recorded $17.7 million of intangible assets. Intangible assets, net were as follows (in thousands): September 30, 2019 Estimated Useful Gross Carrying Accumulated Net Carrying Developed technology 4 - 10 $ 16,032 $ 6,076 $ 9,956 Customer relationships 7 - 12 28,411 8,727 19,684 Customer backlog 1 2,779 2,779 — Contract backlog 0.5 210 210 — Non-compete agreement 2 - 5 662 541 121 Trademarks 8 - 12 1,290 155 1,135 Total intangible assets subject to amortization $ 49,384 $ 18,488 $ 30,896 December 31, 2018 Estimated Useful Gross Carrying Accumulated Net Carrying Developed technology 4 - 10 $ 16,032 $ 3,593 $ 12,439 Customer relationships 7 - 12 28,411 6,085 22,326 Customer backlog 1 2,779 2,779 — Contract backlog 0.5 210 210 — Non-compete agreement 2 - 5 662 398 264 Trademarks 8 - 12 1,290 58 1,232 Total intangible assets subject to amortization $ 49,384 $ 13,123 $ 36,261 We recorded amortization expense related to the acquisition-related intangible assets as follows (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2019 2018 2019 2018 Operating expense category: Research and development $ 828 $ 323 $ 2,484 $ 567 Selling, general and administrative 961 815 2,881 1,552 Total $ 1,789 $ 1,138 $ 5,365 $ 2,119 The estimated future amortization expense of acquisition-related intangible assets subject to amortization after September 30, 2019 is as follows (in thousands): Year Ended December 31, 2019 (remaining 3 months) $ 1,788 2020 7,037 2021 6,962 2022 6,070 2023 3,735 Thereafter 5,304 Total $ 30,896

Investment in Unconsolidated Af

Investment in Unconsolidated Affiliates	9 Months Ended
	Sep. 30, 2019
Investments, All Other Investments [Abstract]
Investment in Unconsolidated Affiliates	Note 6. Investment in Unconsolidated Affiliates. During 2017 and 2016, we made investments in Semitech Semiconductor Pty. Ltd., an Australian corporation (“Semitech”), as part of a license and development agreement dated April 16, 2016. Semitech has developed Narrowband-Power Line Communications (“N-PLC”) products and market knowledge in the N-PLC devices space and plans to sell its products into the smart grid, solar, smart lighting and industrial space. Investments during 2016 through June 14, 2017 were recorded as notes receivable. On June 15, 2017, $0.4 million of notes receivable and accrued interest were converted into 233,335 shares of preferred stock in Semitech. In June 2018, we converted $0.5 million of notes receivable and accrued interest into 312,076 shares of preferred stock in Semitech. During the three months ended September 30, 2019, we invested $0.2 million in additional notes receivable in Semitech. This investment is recorded at cost in other non-current assets on the condensed consolidated balance sheets as of September 30, 2019 and December 31, 2018. As of September 30, 2019 and December 31, 2018, we held investments in notes receivable in Semitech in the amount of $0.6 million and $0.2 million, respectively, which were classified in other non-current assets on the condensed consolidated balance sheets.

Borrowings

Borrowings	9 Months Ended
	Sep. 30, 2019
Debt Disclosure [Abstract]
Borrowings	Note 7. Borrowings. Western Alliance Bank Term Loan. The Company was a party to that certain Business Financing Agreement dated July 7, 2016 and that certain Second Business Financing Modification Agreement, dated September 29, 2017, by and between Western Alliance Bank and the Company (“Credit Facility”). The Credit Facility provided for (i) a term loan of up to $18.0 million (the “Term Loan”) and (ii) a revolving credit line advance (the “Line of Credit”) in the aggregate amount of the lower of (x) $5.0 million and (y) 80% of certain of the Company’s receivables. The Term Loan bore interest at a rate per annum equal to the greater of the prime rate or 3.5%, plus 0.75% and was scheduled to mature in June 2019. The Line of Credit bore interest at a rate per annum equal to the greater of the prime rate or 3.5% plus 0.50%, and was scheduled to mature in July 2018. We made interest-only payments on the Term Loan from July 2016 through September 2016 and began making interest payments and principal payments in 33 equal monthly installments starting October 2016. Prior to the Amendment, the Credit Facility provided that any indebtedness we incurred thereunder was collateralized by substantially all assets of the Company and any domestic subsidiaries, subject to certain customary exceptions. We paid a facility fee of $150,000 as well as a $25,000 diligence fee upon entry into the Credit Facility and an additional $10,000 on July 7, 2017. Additional fees of $25,000 were incurred in connection with the amendment. These fees were recorded as a debt discount and were amortized over the life of the agreement. Borrowings of $12.0 million under this facility were repaid in full in May 2018. In connection with the repayment of this facility, the remaining unamortized debt discount of $66,000 was recorded as interest expense in the condensed consolidated statements of operations. Tennenbaum Capital Partners, LLC Term Loan. One May 8, 2018, we entered into a credit agreement with Tennenbaum Capital Partners, LLC (“Tennenbaum”) (“Credit Agreement”). The Credit Agreement provided for a 1 st lien senior secured term loan of $35.0 million (“Term Loan”). The Term Loan bore interest at a rate per annum equal to the sum of the Libor Rate plus 8.75% and was payable in consecutive quarterly installments starting December 31, 2018. The Term Loan was scheduled to mature on May 8, 2022. The Credit Agreement provided that any indebtedness we incurred thereunder was collateralized by substantially all assets of the Company and any domestic subsidiaries, subject to certain customary exceptions. The Credit Agreement contained customary representations and warranties and affirmative and negative covenants, including maximum consolidated leverage ratios and minimum liquidity. Upon an occurrence of an event of default, under the Credit Facility we could have been required to pay interest on all outstanding obligations under the agreement at a rate of 2% above the otherwise applicable interest rate, and the lender could have accelerated our obligations under the agreement. In connection with the Credit Agreement, Tennenbaum received a warrant to purchase 850,000 shares of common stock at an exercise price of $8.30 and a term of six years. In addition, we paid financing costs of $1.4 million. The financing costs and the value of the warrant, $4.8 million, were recorded as a debt discount and were being amortized over the life of the Credit Agreement. Borrowings of $33.8 million under this facility were repaid in full in September 2019. In addition, the Company was required to pay a prepayment premium of $0.7 million. In connection with the repayment of this facility, the remaining balance of the debt discount was recognized as interest expense. Amortization of debt discount was $5. 1 million for the nine months ended September 30, 2019. Amortization of debt discount was $0.7 million for the nine months ended September 30, 2018. Interest expense incurred under our borrowings was $ 6.0 million and $ 8.8 million for the three and nine months ended September 30, 2019, respectively. Interest expense incurred under our borrowings was $1. 1 million and $ 2.4 million for the three and nine months ended September 30, 2018, respectively

Convertible Senior Notes

Convertible Senior Notes	9 Months Ended
	Sep. 30, 2019
Debt Instruments [Abstract]
Convertible Senior Notes	Note 8. Convertible Senior Notes. On September 23, 2019, the Company completed offering of $80.5 million aggregate principal amount of 4.25% Convertible Senior Notes due 2024 (the "Notes"). The Notes were sold pursuant to an indenture, dated September 23, 2019, between the Company and U.S. Bank National Association (the “Trustee”), referred to herein as the “Indenture.” The Notes are senior, unsecured obligations of the Company. The Notes pay interest at a rate equal to 4.25% per year. Interest on the Notes is payable semiannually in arrears on March 15 and September 15 of each year, beginning March 15, 2020. Interest accrues on the Notes from the last date to which interest has been paid or duly provided for or, if no interest has been paid or duly provided for, from September 23, 2019. Unless earlier converted, redeemed or repurchased, the Notes mature on September 15, 2024. The implied estimated effective rate of the liability component of the Notes is 12.3%. The Notes are convertible into Company common stock at an initial conversion rate of 83.3021 shares per $1,000 principal amount of Notes, subject to adjustment upon certain events. The Notes are convertible, in whole or in part, at the option of the holder, at any time prior to the close of business on the business day immediately preceding June 15, 2024, but only in the following circumstances: (1) during any calendar quarter commencing after the calendar quarter ending on December 31, 2019 (and only during such calendar quarter), if the last reported sale price of the Company’s common stock for each of at least 20 trading days (whether or not consecutive) during the 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding calendar quarter is greater than 130% of the conversion price on such trading day; (2) during the five business day period immediately after any ten consecutive trading day period (the five consecutive trading day period being referred to as the ‘‘measurement period’’) in which the trading price per $1,000 principal amount of the Notes for each trading day of the measurement period was less than 98% of the product of the last reported sale price of the Company’s common stock and the conversion rate on such trading day; (3) upon the occurrence of certain specified corporate events, including fundamental changes (as described in the Indenture); or (4) if the Company calls the Notes for redemption. In addition, regardless of the foregoing circumstances, holders may convert their Notes at any time on or after June 15, 2024 and prior to the close of business on the day immediately preceding the maturity date of the Notes. Upon conversion, the Company may elect to settle by paying or delivering either solely cash, shares of Company common stock or a combination of cash and shares of common stock. In accordance with ASC 470-20, the initial measurement of the Notes at fair value resulted in a liability of $57.9 million, as such, the calculated discount resulted in an implied value of the convertible feature recognized in Capital in excess of Par Value of $22.6 million. Issuance costs include initial purchasers discounts of $3.22 million and other costs of $0.3 million amounting to $3.5 million were allocated to components on a ratable basis as follows; Additional Paid-In Capital, $1.0 million, and Convertible Senior Notes, $2.5 million. The Indenture contains covenants that, among other things, restricts the Company’s ability to merge, consolidate or sell, or otherwise dispose of, all or substantially all of its assets. These limitations are subject to a number of important qualifications and exceptions. The Indenture contains customary Events of Default (as defined in the Indenture), including default in the event the Company fails to pay interest on the Notes when due, and such failure continues for 30 days, or the Company fails to pay the principal of the Notes when due, including at maturity, upon redemption or otherwise; failure to comply with covenants and other obligations under the Indenture, including delivery of required notices and obligations in connection with conversion, in certain cases subject to notice and grace periods; payment defaults and accelerations with respect to other indebtedness of the Company and its significant subsidiaries in the aggregate principal amount of $15.0 million or more; failure by the Company or its significant subsidiaries to pay certain final judgments aggregating in excess of $15.0 million within 60 consecutive days of such final judgment; and specified events involving bankruptcy, insolvency or reorganization of the Company or its significant subsidiaries. Upon an Event of Default, the trustee or the holders of at least 25% in aggregate principal amount of the Notes then outstanding may declare all the Notes to be due and payable immediately. In the case of Events of Default relating to bankruptcy, insolvency or reorganization, all outstanding Notes will become due and payable immediately without further action or notice. The following table summarizes information about the equity and liability components of the Notes (in thousands): September 30, 2019 Fair value of 2024 notes outstanding $ 57,851 Unamortized discount (including unamortized debt issuance cost) (2,536) Total convertible senior notes $ 55,315 Equity component of notes $ 22,649 Less: Issuance costs (987) Additional paid-in capital $ 21,662 In September 2019, in connection with the issuance of the Notes, including the initial purchasers’ exercise of the option to purchase additional Notes, we entered into privately negotiated capped call transactions with certain counterparties (the “Capped Calls”). The Capped Calls are expected to reduce potential dilution to our common stock upon conversion of the Notes and/or offset any cash payments that we are required to make in excess of the principal amount of converted Notes, as the case may be, with such reduction and/or offset subject to a cap. The Capped Calls have an initial strike price of $12.00 per share, subject to certain adjustments, which corresponds to the conversion option strike price in the Notes. The Capped Calls have a cap price equal to $15.86 per share, subject to certain adjustments. The Capped Calls are subject to adjustment upon the occurrence of specified extraordinary events affecting us, including merger events, tender offers and announcement events. In addition, the Capped Calls are subject to certain specified additional disruption events that may give rise to a termination of the Capped Calls, including nationalization, insolvency or delisting, changes in law, failures to deliver, insolvency filings and hedging disruptions. For accounting purposes, the Capped Calls are separate transactions, and not part of the terms of the Notes. As these transactions meet certain accounting criteria, the Capped Calls are recorded in stockholders’ equity and are not accounted for as derivatives. The premium paid for the purchase of the Capped Calls in the amount of $6.2 million has been recorded as a reduction to additional paid-in capital and will not be remeasured.

Segment Information

Segment Information	9 Months Ended
	Sep. 30, 2019
Segment Reporting [Abstract]
Segment Information	Note 9. Segment Information. We operate in one business segment: application-specific, semiconductors and systems. Our chief decision-maker, the President and Chief Executive Officer, evaluates our performance based on company-wide consolidated results. Revenue is evaluated by product category and by geographic region. All of our revenue results from contracts with customers; we have no additional sources of revenue. Product revenue from customers is disaggregated based on the geographic region to which the product is delivered. Revenue by geographic region was as follows (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2019 2018 2019 2018 United States $ 8,648 $ 7,253 $ 24,310 $ 15,472 Rest of Americas 1,015 583 4,608 868 Europe 6,085 5,087 16,989 11,708 Asia Pacific 15,905 8,865 43,502 27,078 Rest of world 375 139 888 286 Total $ 32,028 $ 21,927 $ 90,297 $ 55,412 Long-lived assets are attributed to the geographic region where they are located. Long-lived assets by geographic region were as follows (in thousands): September 30, December 31, 2019 2018 United States $ 3,415 $ 3,879 Asia Pacific 3,868 2,968 Europe 757 238 Total property and equipment, net $ 8,040 $ 7,085 September 30, 2019 United States $ 2,165 Asia Pacific 199 Europe 2,110 Total operating lease right-of-use assets $ 4,474

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2019
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 10. Commitments and Contingencies. Operating Leases. We lease certain manufacturing facilities, warehouses, office space, and equipment under non-cancelable operating leases that expire at various times up to November 2033 and have options to renew most leases, with rentals to be negotiated. Certain of our leases contain provisions for rental adjustments. Operating lease rentals are expensed on a straight-line basis over the life of the lease beginning on the date we take possession of the property. At lease inception, we determine the lease term by assuming the exercise of those renewal options that are reasonably assured. The exercise of lease renewal options is at our sole discretion. The lease term is used to determine whether a lease is financing or operating and is used to calculate straight-line rent expense. Additionally, the depreciable life of leasehold improvements is limited by the expected lease term. Leases with an initial term of 12 months or less are not recorded on the balance sheet; we recognize lease expense for these leases on a straight-line basis over the lease term. The following table reflects our lease assets and our lease liabilities at September 30, 2019 and January 1, 2019 (in thousands). September 30, January 1, 2019 2019 Assets: Operating lease right-of-use assets $ 4,474 $ 4,877 Liabilities: Operating lease liabilities, current $ 1,186 $ 1,116 Operating lease liabilities, non-current $ 5,048 $ 5,917 Lease Costs: The components of lease costs were as follows (in thousands): Nine Months Ended September 30, 2019 Operating lease cost $ 1,626 As of September 30, 2019, the maturity of operating lease liabilities was as follows (in thousands): (In thousands) 2019 (remaining 3 months) $ 519 2020 1,962 2021 1,734 2022 1,569 2023 1,021 Thereafter 2,235 Total lease payments 9,040 Less: Interest (2,806) Present value of lease liabilities $ 6,234 Lease Term and Discount Rate: September 30, 2019 Weighted-average remaining lease term (in years) 7.2 Weighted-average discount rate 11.56 % Other Information: Supplemental 2019 cash flow information related to leases was as follows (in thousands): Nine Months Ended September 30, 2019 Operating cash outflows from operating leases $ 1,626 Right-of-use assets obtained in exchange for new operating lease liabilities $ — Purchase Commitments. As of September 30, 2019, we had purchase commitments with our third-party foundries of $5.0 million. Litigation. We are subject to legal proceedings, claims and litigation, including intellectual property litigation, arising in the ordinary course of business. Such matters are subject to many uncertainties and outcomes and are not predictable with assurance. We accrue amounts that we believe are adequate to address any liabilities related to legal proceedings and other loss contingencies that we believe will result in a probable loss that is reasonably estimable. Indemnification. During the normal course of business, we may make certain indemnities, commitments and guarantees which may include intellectual property indemnities to certain of our customers in connection with the sales of our products and indemnities for liabilities associated with the infringement of other parties’ technology based upon our products. Our exposure under these indemnification provisions is generally limited to the total amount paid by a customer under the agreement. However, certain agreements include indemnification provisions that could potentially expose us to losses in excess of the amount received under the agreement. In addition, we indemnify our officers, directors and certain key employees while they are serving in good faith in such capacities. We have not recorded any liability for these indemnities, commitments and guarantees in the accompanying condensed consolidated balance sheets. Where necessary, we accrue for losses for any known contingent liabilities, including those that may arise from indemnification provisions, when future payment is probable.

Common Stock, Common Stock Warr

Common Stock, Common Stock Warrants and Stock Option Plan	9 Months Ended
	Sep. 30, 2019
Equity [Abstract]
Common Stock, Common Stock Warrants and Stock Option Plan	Note 11. Common Stock, Common Stock Warrants and Stock Option Plan. Common Stock. We are authorized to issue 100,000,000 shares of common stock with $0.0001 par value per share as of September 30, 2019 and December 31, 2018. Each holder of common stock is entitled to one vote per share. As of September 30, 2019, no dividends have been declared by the Board of Directors, however, the holders of common stock are also entitled to receive dividends, when and if declared by our Board of Directors. We completed a follow-on offering of our common stock in June 2017. We sold 5,000,000 shares, including 625,000 shares upon exercise of the underwriters’ option to purchase additional shares. The shares were sold at a public offering price of $4.00 per share for net proceeds of $18.4 million to us, after deducting underwriting discounts, commissions and offering expenses. We completed another follow-on offering of our common stock in July 2018. We sold 7,705,000 shares, including 1,005,000 shares upon exercise of the underwriters’ option to purchase additional shares. The shares were sold at a public offering price of $6.00 per share for net proceeds of $42.7 million to us, after deducting underwriting discounts, commissions and offering expenses. Common Stock Reserved for Future Issuance. As of September 30, 2019 and December 31, 2018, we had reserved shares of common stock for future issuances as follows: September 30, December 31, 2019 2018 Warrants to purchase common stock 1,165,282 1,239,423 Options outstanding 1,958,989 1,865,415 Restricted stock units outstanding 1,617,258 1,154,980 Shares available for future grants 259,998 96,515 Shares available for ESPP 373,428 362,938 Shares reserved for issuance upon conversion of the Notes 8,885,204 — Total 14,260,159 4,719,271 Common Stock Warrants. In connection with the Credit Agreement (Note 7), the Company issued Tennenbaum a warrant to purchase 850,000 shares of common stock at an exercise price of $8.30 per share with a term of six years. The grant date fair value of the warrant was approximately $4.8 million which was recorded as a debt discount and amortized over the life of the Credit Agreement. The fair value of the warrant was determined using the Black-Scholes Model based on the following assumptions: common stock price on date of grant of $8.70, dividend yield of 0%, volatility of 69.73%, a risk-free interest rate 2.87% and a term of 6 years. The following common stock warrants were outstanding: As of September 30, 2019 Total amount of securities issuable under the outstanding warrants Exercise Price Issuance Date Expiration Date $ 2.38 2014-2015 2022-2024 $ 8.30 $ 8.11 Common stock warrants are exercisable at the option of the holder any time after the date of issuance into shares of our common stock. 74,141 warrants with an exercise price of $30.35 expired unexercised on September 27, 2019. Employee Benefit Plans. 2007 Equity Incentive Plan. In 2007, our Board of Directors and shareholders approved the 2007 Equity Incentive Plan (the “2007 Plan”) under which 272,727 shares of common stock were reserved and available for the issuance of stock options and restricted stock to eligible participants. The 2007 Plan was subsequently amended to increase the number of shares of common stock reserved for issuance under the 2007 Plan to 787,878 and during the year ended December 31, 2015, the number of shares reserved for issuance under the 2007 Plan was increased to 2,651,515. Options and restricted stock awards were granted at a price per share not less than the 85% of the fair value at the date of grant or award, respectively. Restricted stock awarded to persons controlling more than 10% of our stock were granted at a price per share not less than the 100% of the fair value at the date of the award. Options that were granted to new employees generally vest over a four-year period with 25% vesting at the end of one year and the remaining to vest monthly thereafter, while options that were granted to existing employees generally vest over a four-year period. Options granted generally are exercisable up to 10 years from the date of grant. As of October 26, 2015, no shares were available for grant under the 2007 Plan and all outstanding options would continue to be governed and remain outstanding in accordance with their existing terms. In addition, any shares subject to outstanding awards under the 2007 Plan that are issuable upon the exercise of options that expire or become unexercisable for any reason without having been exercised in full will be available for future grant and issuance under the 2015 Equity Incentive Plan. 2015 Equity Incentive Plan. In September 2015, our Board of Directors adopted, and in October 2015 our stockholders approved, our 2015 Equity Incentive Plan. The 2015 Equity Incentive Plan became effective on the date immediately prior to the date of our initial public offering (“IPO”). As a result, 1,813,272 shares of common stock previously reserved but unissued under the 2007 Plan on the effective date of the 2015 Equity Incentive Plan became reserved for issuance under our 2015 Equity Incentive Plan, and we ceased granting awards under our 2007 Plan. The number of shares reserved for issuance under our 2015 Equity Incentive Plan will increase automatically on the first day of January of each of 2016 through 2025 by the number of shares equal to 4% of the total outstanding shares of our common stock as of the immediately preceding December 31. However, our Board of Directors may reduce the amount of the increase in any particular year. Our 2015 Equity Incentive Plan authorizes the award of stock options, restricted stock awards, stock appreciation rights, restricted stock units (“RSUs”), performance awards and stock bonuses. No person will be eligible to receive more than 2,000,000 shares in any calendar year under our 2015 Equity Incentive Plan other than a new employee of ours, who will be eligible to receive no more than 4,000,000 shares under the plan in the calendar year in which the employee commences employment. The aggregate number of shares of our common stock that may be subject to awards granted to any one non-employee director pursuant to the 2015 Equity Incentive Plan in any calendar year shall not exceed 300,000. Our 2015 Equity Incentive Plan provides that no more than 25,000,000 shares will be issued as incentive stock options. 2015 Employee Stock Purchase Plan. In September 2015, our Board of Directors adopted, and in October 2015 our stockholders approved, our 2015 Employee Stock Purchase Plan (“ESPP”). The 2015 Employee Stock Purchase Plan became effective on the date of our IPO. We reserved 150,000 shares of our common stock for issuance under our 2015 Employee Stock Purchase Plan. The number of shares reserved for issuance under our 2015 Employee Stock Purchase Plan will increase automatically on the first day of January following the first offering date by the number of shares equal to 1% of the total outstanding shares of our common stock as of the immediately preceding December 31 (rounded to the nearest whole share). However, our Board of Directors may reduce the amount of the increase in any particular year. The aggregate number of shares issued over the term of our 2015 Employee Stock Purchase Plan will not exceed 2,250,000 shares of our common stock. Under our 2015 Employee Stock Purchase Plan, eligible employees will be able to acquire shares of our common stock by accumulating funds through payroll deductions. Eligible employees will be able to select a rate of payroll deduction up to 15% of their base cash compensation. The purchase price for shares of our common stock purchased under our 2015 Employee Stock Purchase Plan will be 85% of the lesser of the fair market value of our common stock on (i) the first trading day of the applicable offering period and (ii) the last trading day of each purchase period in the applicable offering period. Except for the first offering period, each offering period will run for no more than six months, with purchases occurring every six months. The first offering period began upon the effective date of our IPO and was originally set to end on June 30, 2016. On May 25, 2016, the Board of Directors extended the initial offering period to July 31, 2016. Subsequent purchase periods will be 6 months in duration beginning on August 1, 2016. On July 29, 2016, we issued 68,392 shares of common stock in conjunction with the end date of the initial purchase window. During 2017, we issued 110,711 shares of common stock pursuant to the ESPP. On January 31, 2018 we issued 55,806 shares of common stock pursuant to the ESPP. On July 31, 2018 we issued 69,761 shares of common stock pursuant to the ESPP. On January 31, 2019 we issued 129,815 shares of common stock pursuant to the ESPP. On July 31, 2019 we issued 154,116 shares of common stock in conjunction with the end date of the latest purchase window. No participant will have the right to purchase shares of our common stock in an amount that has a fair market value greater than $25,000, determined as of the first day of the applicable purchase period, for each calendar year in which that right is outstanding. In addition, no participant will be permitted to purchase more than 2,500 shares during any one purchase period or a lesser amount as determined by our compensation committee. Our 2015 Employee Stock Purchase Plan will continue until the earlier to occur of its termination by our Board of Directors, the issuance of all shares reserved for issuance under it or the tenth anniversary of its effective date. A summary of stock option and RSUs (including performance-based RSU) activity under the 2007 Plan and the 2015 Equity Incentive Plan is as follows: Stock Options Weighted- Weighted- Average Average Remaining Aggregate Exercise Contractual Intrinsic Shares Price Term (Years) Value (aggregate intrinsic value in thousands) Outstanding as of December 31, 2016 991,895 $ 2.68 6.3 $ 161 Granted 835,480 4.30 Exercised (230,123) 1.92 Canceled (36,799) 4.16 Outstanding as of December 31, 2017 1,560,453 3.63 7.6 $ 4,632 Granted 479,375 7.25 Exercised (112,965) 2.48 Canceled (61,448) 3.65 Outstanding as of December 31, 2018 1,865,415 4.63 7.6 $ 1,540 Granted 189,856 6.16 Exercised (91,173) 3.16 Canceled (5,109) 7.26 Outstanding as of September 30, 2019 1,958,989 $ 4.84 7.2 $ 7,371 Options vested and expected to vest as of September 30, 2019 1,903,094 $ 4.80 7.2 $ 7,241 Options vested and exercisable as of September 30, 2019 1,137,160 $ 4.08 6.4 $ 5,173 Restricted Stock Units Weighted- Weighted- Average Average Remaining Aggregate Grant Date Contractual Intrinsic Shares Fair Value Term (Years) Value (aggregate intrinsic value in thousands) Outstanding as of December 31, 2016 490,954 $ 5.80 0.5 $ 908 Granted 541,513 2.88 Released (497,009) 5.64 Forfeited/expired (25,564) 5.98 Outstanding as of December 31, 2017 509,894 2.84 1.4 $ 3,288 Granted 925,578 6.55 Released (264,568) 4.02 Forfeited/expired (15,924) 8.34 Outstanding as of December 31, 2018 1,154,980 5.50 1.4 $ 5,082 Granted 965,313 6.33 Released (361,742) 5.26 Forfeited/expired (141,293) 4.88 Outstanding as of September 30, 2019 1,617,258 $ 6.10 1.4 $ 13,844

Stock-based Compensation

Stock-based Compensation	9 Months Ended
	Sep. 30, 2019
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-based Compensation	Note 12. Stock-based Compensation. We record stock-based compensation based on fair value as of the grant date using the Black-Scholes option-pricing model for stock options granted and Monte Carlo simulation techniques for certain RSUs with performance-based vesting conditions. We recognize such costs as compensation expense on a straight-line basis over the employee’s requisite service period, which is generally four years. Our valuation assumptions for stock options are as follows: Risk-free interest rate. We base the risk-free interest rate used in the Black-Scholes option-pricing model on the implied yield available on U.S. Treasury zero-coupon issues with an equivalent expected term of the options for each option group. Expected term. The expected term represents the period that our stock-based awards are expected to be outstanding. The expected term assumption is based on the simplified method in which the expected term is equal to the average of the stock-based award’s weighted-average vesting period and its contractual term. We expect to continue using the simplified method until sufficient information about historical behavior is available. Volatility. We determine volatility based on the historical stock volatility of our publicly traded stock. Dividend yield. We have never declared or paid any cash dividend and do not currently plan to pay a cash dividend in the foreseeable future. Consequently, we used an expected dividend yield of zero. The following table summarizes the weighted-average assumptions used in the Black-Scholes option-pricing model to determine fair value of stock options: Three Months Ended Nine Months Ended September 30, September 30, 2019 2018 2019 2018 Volatility 57 % 77 % 65 % 72 % Expected dividend yield — — — — Risk-free rate 1.90 % 2.80 % 2.22 % 2.84 % Expected term (in years) 6 5 6 6 The weighted-average grant date fair value of the options granted under the 2015 Equity Incentive Plan as calculated using the Black-Scholes option-pricing model was $4.40 and $3.68 per share for the three months and nine months ended September 30, 2019, respectively. There were no options granted during the three months ended September 30, 2019. On April 1, 2017, our compensation committee granted 204,220 RSUs that do not begin vesting unless certain performance goals are met. All performance goals must be met in order for the shares to begin vesting. Vesting would begin on the one-year anniversary of the grant date. These performance goals relate to a) the price performance of our common stock one year from the grant date as compared to a threshold established by our compensation committee and b) revenue, gross profit and EBITDA performance relative to plan targets for fiscal 2017 established by our compensation committee. As a result of these performance-based vesting conditions we valued these RSUs using Monte Carlo simulation techniques to establish a fair value per share of $0.81 at the time of grant. On April 1, 2018, our compensation committee granted 102,283 RSUs that do not begin vesting unless certain performance goals are met. Vesting will not begin unless the stock performance goals are met and the number of shares eligible to begin vesting are based on Adesto’s share performance as compared to the Russell 2000 stock index which is the performance threshold established by the compensation committee. The evaluation period for the stock performance is from April 2, 2018 through June 30, 2019. Vesting would begin on the one-year anniversary of the grant date with 20% of the shares vesting immediately and the remaining 80% of the shares vesting over the next eight quarters. As a result of these performance-based vesting conditions we valued these RSUs using Monte Carlo simulation techniques to establish a fair value per share of $4.92 at the time of grant. As of September 30, 2019, Adesto’s share price did not meet the performance threshold and the PRSU’s were not awarded. On March 25, 2019, our compensation committee granted 147,954 RSUs that do not begin vesting unless certain performance goals are met. Vesting of these shares will not begin unless the stock price performance goals are met and the number of shares eligible to begin vesting are based on Adesto’s share performance as compared to the Russell 2000 stock index which is the performance threshold established by the compensation committee. The evaluation period for the stock performance is from March 15, 2019 through March 15, 2020. Vesting would begin on the one-year anniversary of the grant date with 20% of the shares vesting immediately and the remaining 80% of the shares vesting over the next eight quarters. As a result of these performance-based vesting conditions we valued these RSUs using Monte Carlo simulation techniques to establish a fair value per share of $4.05 at the time of grant. Expense for these RSUs is being amortized over three years. The following table presents the effects of stock-based compensation for stock options, RSUs (including performance-based RSUs), and ESPP purchase rights (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2019 2018 2019 2018 Cost of revenue $ 80 $ 56 $ 212 $ 129 Research and development 638 356 1,517 786 Selling, general and administrative 917 528 2,345 1,188 Total $ 1,635 $ 940 $ 4,074 $ 2,103 Stock-based compensation expense capitalized to inventories was not material during the nine months ended September 30, 2019 and 2018. We did not realize any income tax benefit from stock option exercises in any of the periods presented due to recurring losses and valuation allowances. As of September 30, 2019, the total unrecognized compensation cost related to stock options, net of estimated forfeitures, was approximately $ 2.6 million, and this amount is expected to be recognized over a weighted-average period of approximately 2.2 years. As of September 30, 2019, the total unrecognized compensation cost related to RSUs (including performance-based RSUs) and ESPP purchase rights was $7.9 million and $ 163 ,000, respectively, and these amounts are expected to be recognized over 2.4 years and 0.3 years, respectively.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2019
Income Tax Disclosure [Abstract]
Income Taxes	Note 13. Income Taxes. We recorded a provision for (benefit from) income tax of $ 337,000 and ($64,000), respectively, for the three months ended September 30, 2019 and 2018, respectively, and a provision for (benefit from) income tax of $ 236,000 and ($80,000), respectively, for the nine months ended September 30, 2019 and 2018, respectively . The income tax provision is comprised of estimates of current and deferred taxes in domestic and foreign jurisdictions. The income tax provision reflects tax expense associated with foreign taxes, state income tax, uncertain tax positions and tax expense related to the recording of a deferred tax liability that results from the amortization for income tax purposes of acquisition-related goodwill. The decrease in the tax provision between 2019 and 2018 is primarily due to a deferred tax benefit associated with our foreign deferred tax liability and release of tax reserves due to the statute of limitations lapse on such reserve. In December 2017, the Tax Cuts and Jobs Act (“Tax Act”) was enacted. The 2017 Tax Act includes a number of changes to existing U.S. tax laws that impact us, most notably a reduction of the U.S. corporate income tax rate from 35 percent to 21 percent for tax years beginning after December 31, 2017. Due to the complexities involved in accounting for the recently enacted Tax Act, the U.S. Securities and Exchange Commission’s Staff Accounting Bulletin (“SAB”) 118 requires that the Company include in its financial statements a reasonable estimate of the impact of the Tax Act on earnings to the extent such estimate has been determined. Pursuant to the SAB118, the Company is allowed a measurement period of up to one year after the enactment date of the Tax Act to finalize the recording of the related tax impacts. December 22, 2018 marked the end of the measurement period for purposes of SAB 118. As such, the Company has completed the analysis relating to the Act currently available which resulted in no additional SAB 118 tax effect in the fourth quarter of 2018 for the year ended December 31, 2018 . In January 2018, the FASB released guidance on the accounting for tax on the global intangible low-taxed income ("GILTI") provisions of the 2017 Tax Act. The GILTI provisions impose a tax on foreign income in excess of a deemed return on tangible assets of foreign corporations. The guidance indicates that either accounting for deferred taxes related to GILTI inclusions or to treat any taxes on GILTI inclusions as period cost are both acceptable methods subject to an accounting policy election. Effective January 1, 2018, we elected to treat any potential GILTI inclusions as a period cost as we are not projecting any material impact from GILTI inclusions and any deferred taxes related to any inclusion would be immaterial. As of September 30, 2019, our deferred tax assets are fully offset by a valuation allowance except in those jurisdictions where it is determined that a valuation allowance is not required. Accounting for income taxes provides for the recognition of deferred tax assets if realization of such assets is more likely than not. Based on the weight of available evidence, which includes historical operating performance, reported cumulative net losses since inception and difficulty in accurately forecasting our future results, we provided a full valuation allowance against our net U.S. deferred tax assets. We reassess the need for our valuation allowance on a quarterly basis. If it is later determined that a portion or all of the valuation allowance is not required, it generally will be a benefit to the income tax provision in the period that such determination is made. We evaluate tax positions for recognition using a more-likely-than-not recognition threshold, and those tax positions eligible for recognition are measured as the largest amount of tax benefit that is greater than 50% likely of being realized upon the effective settlement with a taxing authority that has full knowledge of all relevant information. We believe that we have provided adequate reserves for our income tax uncertainties in all open tax years. We do not anticipate a material change in the total amount or composition of its unrecognized tax benefits within 12 months of September 30, 2019. We file federal, state and foreign income tax returns in jurisdictions with varying statutes of limitations. Due to our net operating loss and credit carryforwards, our income tax returns generally remain subject to examination by federal, state and international authorities.

Net Loss Per Share

Net Loss Per Share	9 Months Ended
	Sep. 30, 2019
Earnings Per Share [Abstract]
Net Loss Per Share	Note 14. Net Loss Per Share. The following outstanding common stock equivalents were excluded from the computation of diluted net loss per share for the periods presented because including them would have been antidilutive: Three Months Ended Nine Months Ended September 30, September 30, 2019 2018 2019 2018 Stock options 1,958,989 1,844,030 1,958,989 1,844,030 Restricted stock units 1,617,258 1,074,193 1,617,258 1,074,193 Common stock warrants 1,165,282 1,239,423 1,165,282 1,239,423 Shares from the convertible senior notes 6,705,819 — 6,705,819 — 11,447,348 4,157,646 11,447,348 4,157,646

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2019
Related Party Transactions [Abstract]
Related Party Transactions	Note 15. Related Party Transactions. The Company purchases certain wafers from Altis Semiconductor S.N.C., which was acquired by X-FAB Silicon Foundries, a stockholder of the Company, in 2016. There were no payments to X-Fab Silicon Foundries during the nine months ended September 30, 2019 and 2018. As of September 30, 2019 and December 31, 2018, there were no amounts due. On July 27, 2019, Susan Uthayakumar, the president of Schneider Electric, Canada joined the Company’s board of directors. The Company, through Echelon, sells Embedded Systems products to Schneider Electric. From September 14, 2018 (the date on which the Company acquired 100% of the issued capital of Echelon) and through the period ending September 30, 2019, the Company has recognized revenues of approximately $0.6 million from Schneider Electric . As of September 30, 2019 we had approximately $12,000 of outstanding accounts receivable with Schneider Electric.

Restructuring

Restructuring	9 Months Ended
	Sep. 30, 2019
Restructuring and Related Activities [Abstract]
Restructuring	Note 16. Restructuring During the nine months ended September 30, 2019, the Company made the decision to close the lighting business which was acquired as part of the Echelon acquisition in September 2018. The lighting disposal liabilities, expected to be resolved in the next 12 months, include accrued costs for certain estimated warranty expenses, employee severance, additional inventory write-downs, additional bad debts, and additional materials at our subcontractors which have yet to be delivered. The Company recorded a restructuring expense of $1.7 million during the nine months ended September 30, 2019.

Organization and Summary of S_2

Organization and Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Nature of Operations	Organization and Nature of Operations. Adesto Technologies Corporation (together with its subsidiaries; “Adesto”, “we”, “our”, “us” or the “Company”) was incorporated in the state of California in January 2006 and reincorporated in Delaware in October 2015. We are a leading provider of innovative, application-specific semiconductors and systems for the Internet of Things era. Our corporate headquarters are located in Santa Clara, California. On May 9, 2018 we acquired 100% of the issued capital of S3 Asic Semiconductors Limited and on September 14, 2018 we acquired 100% of the issued capital of Echelon Corporation. Our financial results include the operating results of those entities from the date of acquisition.
Basis of Presentation	Basis of Presentation. The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) for interim financial information and with the instructions to Form 10‑Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by U.S. GAAP to complete annual consolidated financial statements. In the opinion of our management, all adjustments (consisting of normal recurring adjustments) considered necessary to present fairly the financial position of the Company and its results of operations and cash flows for the interim periods presented have been included. Operating results for the nine months ended September 30, 2019 are not necessarily indicative of the results that may be expected for the year ending December 31, 2019, for any other interim period or for any other future year. The condensed consolidated balance sheet as of December 31, 2018 was derived from the audited consolidated financial statements as of that date, but does not include all of the disclosures required by U.S. GAAP. The accompanying condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto contained in the Company’s Annual Report on Form 10‑K for the year ended December 31, 2018, filed with the Securities and Exchange Commission on March 18, 2019. The condensed consolidated financial statements include the results of our operations, and the operations of our wholly owned subsidiaries. All intercompany balances and transactions have been eliminated. There have been no material changes to our significant accounting policies described in Note 1, Organization and Summary of Significant Accounting Policies, in Notes to Consolidated Financial Statements in Item 8 of Part II of our Annual Report on Form 10‑K for the year ended December 31, 2018 that have had a material impact on our condensed consolidated financial statements and related notes, except as described below.
Recent Accounting Pronouncements and Recently Adopted Accounting Pronouncements	Recent Accounting Pronouncements. In August 2018, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2018-13, Fair Value Measurement Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement. As part of the FASB's disclosure framework project, it has eliminated, amended and added disclosure requirements for fair value measurements. Entities will no longer be required to disclose the amount of, and reasons for, transfers between Level 1 and Level 2 of the fair value hierarchy, the policy of timing of transfers between levels of the fair value hierarchy and the valuation processes for Level 3 fair value measurements. Public companies will be required to disclose the range and weighted average used to develop significant unobservable inputs for Level 3 fair value measurements. This ASU is effective for public entities for annual and interim periods beginning after December 15, 2019. Early adoption is permitted as of the beginning of any interim or annual reporting period. This ASU will have an impact on the Company's disclosures. In January 2017, the FASB issued ASU No. 2017-04, Intangibles—Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment. This ASU eliminates Step 2 from the goodwill impairment test. Instead, an entity should recognize an impairment charge for the amount by which the carrying value exceeds the reporting unit’s fair value, not to exceed the total amount of goodwill allocated to that reporting unit. This ASU is effective for annual or any interim goodwill impairment tests in fiscal years beginning after December 15, 2019. The Company is currently evaluating the effect of the adoption of this ASU, but anticipates that the adoption will not have a material impact on its consolidated financial statements. In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. This ASU requires instruments measured at amortized cost to be presented at the net amount expected to be collected. Entities are also required to record allowances for available-for-sale debt securities rather than reduce the carrying amount. This ASU is effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. The Company expects that the adoption will not have a material impact on its consolidated financial statements. Recently Adopted Accounting Pronouncements. Adoption of ASC 842: We adopted ASU No. 2016-02, Leases (“Topic 842”), as of January 1, 2019, using the modified retrospective approach. The modified retrospective approach provides a method for recording existing leases at the beginning of the period of adoption. In addition, we elected the package of practical expedients permitted under the transition guidance within the new standard, which among other things, allowed us to carry forward the historical lease classification and we elected the hindsight practical expedient to determine the lease term for existing leases. We determined that most renewal options would not be reasonably certain in determining the expected lease term. The comparative information has not been restated and continues to be reported under the accounting standards in effect for those periods. Adoption of the new standard resulted in the recording of right of use assets of $4.9 million and lease liabilities of $7.0 million and eliminating deferred rent of $2.4 million, as of January 1, 2019. The standard did not have an impact on our consolidated results of operations or cash flows. The effect of the changes made to our consolidated January 1, 2019 balance sheet for the adoption of the new lease standard was as follows (in thousands): Balance as of Adjustments Balance as of December 31, Due to January 1, 2018 ASC 842 2019 Operating lease right-of-use assets $ — $ 4,877 $ 4,877 Total assets $ 137,188 $ 4,877 $ 142,065 Operating lease liabilities, current $ — $ 1,116 $ 1,116 Operating lease liabilities, non-current $ — $ 5,917 $ 5,917 Deferred rent $ 2,404 (2,404) — Total liabilities $ 74,446 $ 4,629 $ 79,075 Accumulated deficit $ (121,284) $ 248 $ (121,036) Total stockholders' equity $ 62,742 $ 248 $ 62,990 Total liabilities and stockholders' equity $ 137,188 $ 4,877 $ 142,065
Revenue Recognition	Revenue Recognition. Revenue is recognized when control of the promised goods or services is transferred to customers, in an amount that reflects the consideration we expect to be entitled to in exchange for those goods or services. Sales of products with alternative use account for the majority of our revenue and are recognized at a point in time, the timing of such recognition remained the same under Topic 606. Taxes assessed by a governmental authority that are both imposed on and concurrent with a specific revenue-producing transaction, that are collected by us from a customer and deposited with the relevant government authority, are excluded from revenue. Our revenue arrangements do not contain significant financing components. Revenue is recognized over a period of time when it is assessed that performance obligations are satisfied over a period rather than at a point in time. When any of the following criteria is fulfilled, revenue is recognized over a period of time: (a) The customer simultaneously receives and consumes the benefits provided by the performance as Adesto performs. (b) Adesto’s performance creates or enhances an asset (for example, work in process) that the customer controls as the asset is created or enhanced. (c) Adesto’s performance does not create an asset with an alternative use, and Adesto has an enforceable right to payment for performance completed to date. If revenue is recognized over a period of time, we would then select an appropriate method for measuring progress toward complete satisfaction of the performance obligation, usually costs incurred to date relative to the total expected costs to the satisfaction of that performance obligation. Typically, our revenue is recognized at a point in time. Sales to certain distributors are made under arrangements which provide the distributors with price adjustments, price protection, stock rotation and other allowances under certain circumstances. These adjustments and allowances are accounted for as variable consideration. We estimate these amounts based on the expected amount to be provided to customers and reduce revenue recognized. We believe that there will not be significant changes to our estimates of variable consideration. If a customer pays consideration, or Adesto has a right to an amount of consideration that is unconditional before we transfer a good or service to the customer, those amounts are classified as deferred income/ advances received from customers which are included in other current liabilities or other long-term liabilities when the payment is made or it is due, whichever is earlier. If the arrangement includes variable contingent consideration, we recognize revenue over time if we can reasonably measure its progress, or we are capable of providing reliable information that would be required to apply an appropriate method of measuring progress. To date, we have not had any arrangements incorporating contingent consideration. Sales commissions are owed and are recorded at the time of sell through of our products to end customers. These costs are recorded within selling, general and administrative expenses. The Company has entered into, and will continue to enter into, development agreements. Typically, revenue is recognized over time on a percentage of completion basis based on resources expended to date as compared to budgeted resources. Cost associated with these contracts can be classified as cost of revenue or research and development expense depending on the terms of the contract. We do not disclose the value of unsatisfied performance obligations for (i) contracts with an original expected length of one year or less and (ii) contracts for which we recognize revenue at the amount to which we have the right to invoice for services performed. Timing of Revenue Recognition. Three Months Ended Nine Months Ended September 30, September 30, 2019 2018 2019 2018 (in thousands) Products transferred at a point in time $ 26,023 $ 18,250 $ 76,480 $ 49,748 Products and services transferred over time 6,005 3,677 13,817 5,664 $ 32,028 $ 21,927 $ 90,297 $ 55,412 The following table reflects the changes in our contract assets, which we classify as accounts receivable, unbilled and our contract liabilities which we classify as deferred revenue: September 30, December 31, 2019 2018 Change (in thousands) Contract assets: Accounts receivable, unbilled $ 3,863 $ 751 $ 3,112 Contract liabilities: Deferred revenue $ 649 $ 1,848 $ (1,199) Accounts receivable, unbilled represents revenue recognized on certain development contracts for which invoicing has not yet occurred based on the terms of the development contract. As of September 30, 2019 and December 31, 2018, we had $3.9 million and $0.8 million, respectively, classified as unbilled accounts receivable within accounts receivable. Deferred revenue represents amounts invoiced to customers for certain development contracts for which revenue has yet to be recognized based on actual development hours performed. Typically, the timing of invoicing is based on the terms of the contract. As of September 30, 2019 and December 31, 2018, we had $0.6 million and $1.8 million, respectively, of deferred revenue classified as accrued expenses and other current liabilities.
Reclassifications	Reclassifications. Certain reclassifications have been made to prior periods’ condensed consolidated financial statements to conform to the current period presentation. These reclassifications did not result in any change in previously reported total assets, stockholders’ equity or net loss.
Use of Estimates	Use of Estimates. The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates, judgments and assumptions that affect the reported amount of assets, liabilities, revenue and expenses and related disclosures of contingent assets and liabilities. On an on-going basis, we evaluate those estimates, including those related to allowances for doubtful accounts, price adjustments and other revenue reserves, warranty accrual, inventory write-downs, valuation of long-lived assets, including property and equipment and identifiable intangible assets and goodwill, loss on purchase commitments, valuation of deferred taxes and contingencies. In addition, we use assumptions when employing the Black-Scholes option-pricing model to calculate the fair value of stock options granted and Monte Carlo simulation techniques to value certain restricted stock units with market-based vesting conditions. We base our estimates of the carrying value of certain assets and liabilities on historical experience and on various other assumptions that are believed to be reasonable under the circumstances, when these carrying values are not readily available from other sources. Actual results could differ from these estimates.
Product Warranty	Product Warranty. Our non-volatile memory (“NVM”) products are sold with a limited warranty for a period of one year, warranting that the product conforms to specifications and is free from material defects in design, materials and workmanship. To date, we have had insignificant returns of any defective production parts. During 2018 and the nine months ended September 30, 2019, we did not record any additional liability related to potential warranty claims. As of September 30, 2019 and December 31, 2018, the warranty accrual related to NVM products was $51,000 and is included in accrued expenses and other current liabilities on the condensed consolidated balance sheets. At the time of the Echelon acquisition we recorded a warranty liability of $401,000 related to Echelon products. During 2018 and the nine months ended September 30, 2019, the warranty liability increased by $53,000 and decreased by $1,000, res pectively . As of September 30, 2019 and December 31, 2018, the warranty accrual related to Echelon products was $453,000 and $454,000, respectively, and is included in accrued expenses and other current liabilities on the condensed consolidated balance sheets.
Foreign Currency Translation	Foreign Currency Translation. The functional currency of our foreign subsidiaries is the local currency. In consolidation, we translate assets and liabilities at exchange rates in effect at the consolidated balance sheet date. We translate revenue and expense accounts at the average exchange rates during the period in which the transaction takes place. Net gains and losses from foreign currency translation of assets and liabilities were losses of $299,000 and $148,000 for the three months ended September 30, 2019 and 2018, respectively, and $383,000 and $65,000 for the nine months ended September 30, 2019 and 2018, respectively, and are included in the cumulative translation adjustment component of accumulated other comprehensive loss, net of tax, a component of stockholders’ equity. Net gains and losses arising from transactions denominated in currencies other than the functional currency were gains of $181,000 and $9,000 for the three months ended September 30, 2019 and 2018, respectively, and a gain of $31,000 and a loss of $1,000 for the nine months ended September 30, 2019 and 2018, respectively, and are included in other income, net in the condensed consolidated statements of operations.
Concentration of Risk	Concentration of Risk. Our products are primarily manufactured, assembled and tested by third-party foundries and other contractors in Asia and we are heavily dependent on a single foundry in Taiwan for the manufacture of wafers and a single contractor in the Philippines for assembly and testing of our products. We do not have long-term agreements with either of these suppliers. A significant disruption in the operations of these parties would adversely impact the production of our products for a substantial period of time, which could have a material adverse effect on our business, financial condition, operating results and cash flows. Financial instruments that potentially subject us to significant concentrations of credit risk consist principally of cash and cash equivalents, investments and accounts receivables. We place substantially all of our cash and cash equivalents and investments on deposit with a reputable, high credit quality financial institution in the United States of America. We believe that the bank that holds substantially all of our cash and cash equivalents and investments is financially sound and, accordingly, subject to minimal credit risk. Deposits held with the bank may exceed the amount of insurance provided on such deposits. We generally do not require collateral or other security in support of accounts receivable. We periodically review the need for an allowance for doubtful accounts by considering factors such as historical experience, credit quality, the age of the accounts receivable balances and current economic conditions that may affect a customer’s ability to pay. The allowance for doubtful accounts as of September 30, 2019 and December 31, 2018 was $60,000 and $30,000, respectively. Customer concentrations as a percentage of revenue, net were as follows: Three Months Ended Nine Months Ended September 30, September 30, 2019 2018 2019 2018 Customer A * 20 % 17 % 21 % Customer B 23 % * 12 % * * Customer concentrations as a percentage of gross accounts receivable were as follows: September 30, December 31, 2019 2018 Customer B 28 % 13 %

Organization and Summary of S_3

Organization and Summary of Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Adoption of New Standard and Impact of Adoption on Select Condensed Consolidated Balance Sheet	The effect of the changes made to our consolidated January 1, 2019 balance sheet for the adoption of the new lease standard was as follows (in thousands): Balance as of Adjustments Balance as of December 31, Due to January 1, 2018 ASC 842 2019 Operating lease right-of-use assets $ — $ 4,877 $ 4,877 Total assets $ 137,188 $ 4,877 $ 142,065 Operating lease liabilities, current $ — $ 1,116 $ 1,116 Operating lease liabilities, non-current $ — $ 5,917 $ 5,917 Deferred rent $ 2,404 (2,404) — Total liabilities $ 74,446 $ 4,629 $ 79,075 Accumulated deficit $ (121,284) $ 248 $ (121,036) Total stockholders' equity $ 62,742 $ 248 $ 62,990 Total liabilities and stockholders' equity $ 137,188 $ 4,877 $ 142,065
Schedule of Timing of Revenue Recognition	Three Months Ended Nine Months Ended September 30, September 30, 2019 2018 2019 2018 (in thousands) Products transferred at a point in time $ 26,023 $ 18,250 $ 76,480 $ 49,748 Products and services transferred over time 6,005 3,677 13,817 5,664 $ 32,028 $ 21,927 $ 90,297 $ 55,412
Schedule of Contract Assets and Contract Liabilities	September 30, December 31, 2019 2018 Change (in thousands) Contract assets: Accounts receivable, unbilled $ 3,863 $ 751 $ 3,112 Contract liabilities: Deferred revenue $ 649 $ 1,848 $ (1,199)
Schedule of Customer Concentration as Percentage of Total Revenue and Gross Receivable	Customer concentrations as a percentage of revenue, net were as follows: Three Months Ended Nine Months Ended September 30, September 30, 2019 2018 2019 2018 Customer A * 20 % 17 % 21 % Customer B 23 % * 12 % * * Customer concentrations as a percentage of gross accounts receivable were as follows: September 30, December 31, 2019 2018 Customer B 28 % 13 %

Acquisitions (Tables)

Acquisitions (Tables)	9 Months Ended
	Sep. 30, 2019
Echelon Corporation [Member]
Business Acquisition [Line Items]
Schedule of Purchase Price Allocation	The following table summarizes the fair values of assets acquired and liabilities assumed (in thousands): Cash $ 15,270 Short term investments 1,274 Accounts receivable 3,020 Inventories 5,710 Other current assets 2,845 Property and equipment, net 614 Intangible assets 17,690 Goodwill 4,266 Other non-current assets 252 Accounts payable (3,630) Other current liabilities (2,642) Other non-current liabilities (563) Fair value of net assets acquired $ 44,106
Schedule of Intangible Assets Acquired	Fair Value Useful (in thousands) Customer relationships $ 6,520 7 Developed technology 10,670 4 Trademarks 500 8 Total acquired intangible assets $ 17,690
S3 Asic Semiconductors Limited [Member]
Business Acquisition [Line Items]
Schedule of Purchase Price Allocation	The following table summarizes the fair values of assets acquired and liabilities assumed (in thousands): Cash $ 267 Accounts receivable 192 Other current assets 883 Property and equipment, net 191 Intangible assets 15,340 Goodwill 34,352 Accounts payable (37) Deferred revenue (129) Earn-out liability, current (10,218) Other current liabilities (761) Deferred tax liability (1,918) Earn-out liability, non-current (3,279) Fair value of net assets acquired $ 34,883
Schedule of Intangible Assets Acquired	Fair Value Useful (in thousands) Customer relationships $ 12,880 7 Contract backlog 210 0.5 Developed technology 1,080 5 Non-compete agreements 380 2 Trademarks 790 12 Total $ 15,340

Balance Sheet Components (Table

Balance Sheet Components (Tables)	9 Months Ended
	Sep. 30, 2019
Balance Sheet Related Disclosures [Abstract]
Schedule of Accounts Receivable, Net	Accounts receivable, net consisted of the following (in thousands): September 30, December 31, 2019 2018 Accounts receivable $ 30,110 $ 22,490 Accounts receivable, unbilled 3,863 751 Allowance for doubtful accounts (60) (30) Total accounts receivable, net $ 33,913 $ 23,211
Schedule of Inventories	Inventories consisted of the following (in thousands): September 30, December 31, 2019 2018 Raw materials $ 2,213 $ 1,427 Work-in-process 8,019 11,451 Finished goods 6,111 5,757 Total inventories $ 16,343 $ 18,635
Schedule of Property and Equipment, Net	Property and equipment, net consisted of the following (in thousands): September 30, December 31, 2019 2018 Machinery and equipment $ 17,136 $ 15,537 Leasehold improvements 4,418 4,422 Computer software 4,328 3,760 Furniture and fixtures 934 372 Construction in progress 115 52 Property and equipment, at cost 26,931 24,143 Accumulated depreciation and amortization (18,891) (17,058) Property and equipment, net $ 8,040 $ 7,085
Schedule of Accrued Expenses and Other Current Liabilities	Accrued expenses and other current liabilities consisted of the following (in thousands): September 30, December 31, 2019 2018 Accrued sales commission payable $ 260 $ 387 Accrued manufacturing expenses 1,023 692 Liabilities to certain customers — 366 Warranty reserve 504 505 Lighting disposal liabilities 1,404 — Deferred revenue, current portion 649 1,848 Other accrued liabilities 1,932 1,374 Total accrued expenses and other current liabilities $ 5,772 $ 5,172

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2019
Fair Value Disclosures [Abstract]
Schedule of Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis	Fair Value Measurement at Reporting Date Using Significant Quoted Prices in Other Significant Active Markets Observable Unobservable for Identical Inputs Inputs Assets (Level 1) (Level 2) (Level 3) Total (in thousands) As of September 30, 2019 Assets: Money market funds $ 460 $ — $ — $ 460 U.S. government securities 300 — — 300 $ 760 $ — $ — $ 760 Liabilities: Earn-out liability $ — $ — $ 10,130 $ 10,130 As of December 31, 2018 Assets: Money market funds $ 458 $ — $ — $ 458 U.S. government securities 1,282 — — 1,282 $ 1,740 $ — $ — $ 1,740 Liabilities: Earn-out liability $ — $ — $ 10,450 $ 10,450
Schedule of Reconciliation of Change Fair Value	Changes in the earn-out liability during 2019 was as follows (in thousands): Balance as of January 1, 2019 $ 10,450 Acquisitions — Change in fair value (320) Change in foreign currency exchange rate — Balance as of September 30, 2019 $ 10,130

Intangible Assets, net (Tables)

Intangible Assets, net (Tables)	9 Months Ended
	Sep. 30, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Intangible Assets	Intangible assets, net were as follows (in thousands): September 30, 2019 Estimated Useful Gross Carrying Accumulated Net Carrying Developed technology 4 - 10 $ 16,032 $ 6,076 $ 9,956 Customer relationships 7 - 12 28,411 8,727 19,684 Customer backlog 1 2,779 2,779 — Contract backlog 0.5 210 210 — Non-compete agreement 2 - 5 662 541 121 Trademarks 8 - 12 1,290 155 1,135 Total intangible assets subject to amortization $ 49,384 $ 18,488 $ 30,896 December 31, 2018 Estimated Useful Gross Carrying Accumulated Net Carrying Developed technology 4 - 10 $ 16,032 $ 3,593 $ 12,439 Customer relationships 7 - 12 28,411 6,085 22,326 Customer backlog 1 2,779 2,779 — Contract backlog 0.5 210 210 — Non-compete agreement 2 - 5 662 398 264 Trademarks 8 - 12 1,290 58 1,232 Total intangible assets subject to amortization $ 49,384 $ 13,123 $ 36,261
Schedule of Amortization Expense of Intangible Assets	We recorded amortization expense related to the acquisition-related intangible assets as follows (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2019 2018 2019 2018 Operating expense category: Research and development $ 828 $ 323 $ 2,484 $ 567 Selling, general and administrative 961 815 2,881 1,552 Total $ 1,789 $ 1,138 $ 5,365 $ 2,119
Schedule of Finite-Lived Intangible Assets, Annual Expected Amortization Expense	The estimated future amortization expense of acquisition-related intangible assets subject to amortization after September 30, 2019 is as follows (in thousands): Year Ended December 31, 2019 (remaining 3 months) $ 1,788 2020 7,037 2021 6,962 2022 6,070 2023 3,735 Thereafter 5,304 Total $ 30,896

Convertible Senior Notes (Table

Convertible Senior Notes (Tables)	9 Months Ended
	Sep. 30, 2019
Debt Instruments [Abstract]
Summary of Equity and Liability Components of Notes	The following table summarizes information about the equity and liability components of the Notes (in thousands): September 30, 2019 Fair value of 2024 notes outstanding $ 57,851 Unamortized discount (including unamortized debt issuance cost) (2,536) Total convertible senior notes $ 55,315 Equity component of notes $ 22,649 Less: Issuance costs (987) Additional paid-in capital $ 21,662

Segment Information (Tables)

Segment Information (Tables)	9 Months Ended
	Sep. 30, 2019
Segment Reporting [Abstract]
Schedule of Product Revenue from Customers Based on Geographic Region	Product revenue from customers is disaggregated based on the geographic region to which the product is delivered. Revenue by geographic region was as follows (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2019 2018 2019 2018 United States $ 8,648 $ 7,253 $ 24,310 $ 15,472 Rest of Americas 1,015 583 4,608 868 Europe 6,085 5,087 16,989 11,708 Asia Pacific 15,905 8,865 43,502 27,078 Rest of world 375 139 888 286 Total $ 32,028 $ 21,927 $ 90,297 $ 55,412
Schedule of Long-Lived Assets by Geographic Region	Long-lived assets are attributed to the geographic region where they are located. Long-lived assets by geographic region were as follows (in thousands): September 30, December 31, 2019 2018 United States $ 3,415 $ 3,879 Asia Pacific 3,868 2,968 Europe 757 238 Total property and equipment, net $ 8,040 $ 7,085 September 30, 2019 United States $ 2,165 Asia Pacific 199 Europe 2,110 Total operating lease right-of-use assets $ 4,474

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2019
Commitments and Contingencies Disclosure [Abstract]
Schedule of Lease Assets and Lease Liabilities	The following table reflects our lease assets and our lease liabilities at September 30, 2019 and January 1, 2019 (in thousands). September 30, January 1, 2019 2019 Assets: Operating lease right-of-use assets $ 4,474 $ 4,877 Liabilities: Operating lease liabilities, current $ 1,186 $ 1,116 Operating lease liabilities, non-current $ 5,048 $ 5,917
Schedule of Lease Costs	The components of lease costs were as follows (in thousands): Nine Months Ended September 30, 2019 Operating lease cost $ 1,626
Schedule of Maturity of Operating Lease Liabilities	As of September 30, 2019, the maturity of operating lease liabilities was as follows (in thousands): (In thousands) 2019 (remaining 3 months) $ 519 2020 1,962 2021 1,734 2022 1,569 2023 1,021 Thereafter 2,235 Total lease payments 9,040 Less: Interest (2,806) Present value of lease liabilities $ 6,234
Schedule of Lease Term and Discount Rate	September 30, 2019 Weighted-average remaining lease term (in years) 7.2 Weighted-average discount rate 11.56 %
Schedule of Supplemental Cash Flow Information	Supplemental 2019 cash flow information related to leases was as follows (in thousands): Nine Months Ended September 30, 2019 Operating cash outflows from operating leases $ 1,626 Right-of-use assets obtained in exchange for new operating lease liabilities $ —

Common Stock, Common Stock Wa_2

Common Stock, Common Stock Warrants and Stock Option Plan (Tables)	9 Months Ended
	Sep. 30, 2019
Equity [Abstract]
Schedule of Stock Reserved for Future Issuance	September 30, December 31, 2019 2018 Warrants to purchase common stock 1,165,282 1,239,423 Options outstanding 1,958,989 1,865,415 Restricted stock units outstanding 1,617,258 1,154,980 Shares available for future grants 259,998 96,515 Shares available for ESPP 373,428 362,938 Shares reserved for issuance upon conversion of the Notes 8,885,204 — Total 14,260,159 4,719,271
Summary of Outstanding Common Stock Warrants	As of September 30, 2019 Total amount of securities issuable under the outstanding warrants Exercise Price Issuance Date Expiration Date $ 2.38 2014-2015 2022-2024 $ 8.30 $ 8.11
Summary of Stock Option Activity	Stock Options Weighted- Weighted- Average Average Remaining Aggregate Exercise Contractual Intrinsic Shares Price Term (Years) Value (aggregate intrinsic value in thousands) Outstanding as of December 31, 2016 991,895 $ 2.68 6.3 $ 161 Granted 835,480 4.30 Exercised (230,123) 1.92 Canceled (36,799) 4.16 Outstanding as of December 31, 2017 1,560,453 3.63 7.6 $ 4,632 Granted 479,375 7.25 Exercised (112,965) 2.48 Canceled (61,448) 3.65 Outstanding as of December 31, 2018 1,865,415 4.63 7.6 $ 1,540 Granted 189,856 6.16 Exercised (91,173) 3.16 Canceled (5,109) 7.26 Outstanding as of September 30, 2019 1,958,989 $ 4.84 7.2 $ 7,371 Options vested and expected to vest as of September 30, 2019 1,903,094 $ 4.80 7.2 $ 7,241 Options vested and exercisable as of September 30, 2019 1,137,160 $ 4.08 6.4 $ 5,173
Summary of Restricted Stock Units Activity	Restricted Stock Units Weighted- Weighted- Average Average Remaining Aggregate Grant Date Contractual Intrinsic Shares Fair Value Term (Years) Value (aggregate intrinsic value in thousands) Outstanding as of December 31, 2016 490,954 $ 5.80 0.5 $ 908 Granted 541,513 2.88 Released (497,009) 5.64 Forfeited/expired (25,564) 5.98 Outstanding as of December 31, 2017 509,894 2.84 1.4 $ 3,288 Granted 925,578 6.55 Released (264,568) 4.02 Forfeited/expired (15,924) 8.34 Outstanding as of December 31, 2018 1,154,980 5.50 1.4 $ 5,082 Granted 965,313 6.33 Released (361,742) 5.26 Forfeited/expired (141,293) 4.88 Outstanding as of September 30, 2019 1,617,258 $ 6.10 1.4 $ 13,844

Stock-based Compensation (Table

Stock-based Compensation (Tables)	9 Months Ended
	Sep. 30, 2019
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of Weighted Average Assumptions Used to Value Options	Three Months Ended Nine Months Ended September 30, September 30, 2019 2018 2019 2018 Volatility 57 % 77 % 65 % 72 % Expected dividend yield — — — — Risk-free rate 1.90 % 2.80 % 2.22 % 2.84 % Expected term (in years) 6 5 6 6
Schedule of Employee Service Share-based Compensation for Stock Options, Restricted Stock Units and ESPP Shares	The following table presents the effects of stock-based compensation for stock options, RSUs (including performance-based RSUs), and ESPP purchase rights (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2019 2018 2019 2018 Cost of revenue $ 80 $ 56 $ 212 $ 129 Research and development 638 356 1,517 786 Selling, general and administrative 917 528 2,345 1,188 Total $ 1,635 $ 940 $ 4,074 $ 2,103

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	9 Months Ended
	Sep. 30, 2019
Earnings Per Share [Abstract]
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share	Three Months Ended Nine Months Ended September 30, September 30, 2019 2018 2019 2018 Stock options 1,958,989 1,844,030 1,958,989 1,844,030 Restricted stock units 1,617,258 1,074,193 1,617,258 1,074,193 Common stock warrants 1,165,282 1,239,423 1,165,282 1,239,423 Shares from the convertible senior notes 6,705,819 — 6,705,819 — 11,447,348 4,157,646 11,447,348 4,157,646

Organization and Summary of S_4

Organization and Summary of Significant Accounting Policies - Organization and Nature of Operations (Details)	Sep. 14, 2018	May 09, 2018
S3 Asic Semiconductors Limited [Member]
Business Acquisition, Date of Acquisition [Abstract]
Date of Acquisition		May 9, 2018
Business Combination, Description [Abstract]
Percentage of issued capital acquired (as a percent)		100.00%
Echelon Corporation [Member]
Business Acquisition, Date of Acquisition [Abstract]
Date of Acquisition	Sep. 14, 2018
Business Combination, Description [Abstract]
Percentage of issued capital acquired (as a percent)	100.00%

Organization and Summary of S_5

Organization and Summary of Significant Accounting Policies - Adoption of ASC 842 - Practical Expedients (Details)	9 Months Ended
	Sep. 30, 2019
Lessee Disclosure [Abstract]
Lease, Practical Expedients, Package	true
Lease, Practical Expedient, Use of Hindsight	true

Organization and Summary of S_6

Organization and Summary of Significant Accounting Policies - Adoption of ASC 842 - General information (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Jan. 01, 2019	Dec. 31, 2018
Assets and Liabilities, Lessee [Abstract]
Operating lease right-of-use assets	$ 4,474	$ 4,877
Operating lease liabilities	$ 6,234	$ 7,000
Deferred rent			$ 2,404

Organization and Summary of S_7

Organization and Summary of Significant Accounting Policies - Adoption of ASC 842 - Tabular Disclosure (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Jan. 01, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease right-of-use assets	$ 4,474			$ 4,877
Total assets	174,333			142,065	$ 137,188
Operating lease liabilities, current	1,186			1,116
Operating lease liabilities, non-current	5,048			5,917
Deferred rent					2,404
Total liabilities	109,819			79,075	74,446
Accumulated deficit	(139,974)			(121,036)	(121,284)
Total stockholders' equity	64,514	$ 54,534	$ 57,362	62,990	62,742	$ 68,329	$ 33,061	$ 37,347	$ 32,950
Total liabilities and stockholders' equity	$ 174,333			142,065	$ 137,188
Accounting Standards Update 2016-02 [Member] | Restatement Adjustment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease right-of-use assets				4,877
Total assets				4,877
Operating lease liabilities, current				1,116
Operating lease liabilities, non-current				5,917
Deferred rent				(2,404)
Total liabilities				4,629
Accumulated deficit				248
Total stockholders' equity				248
Total liabilities and stockholders' equity				$ 4,877

Organization and Summary of S_8

Organization and Summary of Significant Accounting Policies - Revenue Recognition - Practical Expedients (Details)	9 Months Ended
	Sep. 30, 2019
Revenue, Remaining Performance Obligation, Optional Exemption [Abstract]
Revenue, Remaining Performance Obligation, Optional Exemption, Performance Obligation	true

Organization and Summary of S_9

Organization and Summary of Significant Accounting Policies - Revenue Recognition - Timing of Revenue Recognition (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Disaggregation of Revenue [Line Items]
Revenue, net	$ 32,028	$ 21,927	$ 90,297	$ 55,412
Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue, net	26,023	18,250	76,480	49,748
Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue, net	$ 6,005	$ 3,677	$ 13,817	$ 5,664

Organization and Summary of _10

Organization and Summary of Significant Accounting Policies - Revenue Recognition - Contract Assets and Liabilities (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Contract with Customer, Asset, after Allowance for Credit Loss [Abstract]
Accounts receivable, unbilled	$ 3,863	$ 751
Contract assets, change	3,112
Contract with Customer, Liability [Abstract]
Deferred revenue	649	$ 1,848
Contract liabilities, change	$ (1,199)

Organization and Summary of _11

Organization and Summary of Significant Accounting Policies - Product Warranty (Details) - USD ($) $ in Thousands	Sep. 14, 2014	Sep. 30, 2019	Dec. 31, 2018
Product Warranties Disclosures [Abstract]
Product warranty accrual, current		$ 504	$ 505
Non-volatile Memory Products [Member]
Product Warranties Disclosures [Abstract]
Product warranty		Our non-volatile memory ("NVM") products are sold with a limited warranty for a period of one year, warranting that the product conforms to specifications and is free from material defects in design, materials and workmanship.
Product warranty period		1 year
Product warranty accrual recorded		$ 0	0
Product warranty accrual, current		51	51
Products of Acquiree [Member]
Product Warranties Disclosures [Abstract]
Product warranty accrual recorded	$ 401	1	53
Product warranty accrual, current		$ 453	$ 454

Organization and Summary of _12

Organization and Summary of Significant Accounting Policies - Foreign Currency Translation (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Net gains and losses from foreign currency translation of assets and liabilities	$ (299)	$ 44	$ (128)	$ (148)	$ 100	$ (17)	$ (383)	$ (65)
Net gains and losses arising from transactions denominated in currencies other than the functional currency	$ (181)			$ (9)			$ 31	$ (1)

Organization and Summary of _13

Organization and Summary of Significant Accounting Policies - Concentrations Risk - Allowance for Doubtful Accounts (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Allowance for doubtful accounts	$ 60	$ 30

Organization and Summary of _14

Organization and Summary of Significant Accounting Policies - Concentrations Risk - Revenue (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Maximum
Concentration Risk [Line Items]
Concentration risk percentage (as a percent)		10.00%		10.00%
Customer Concentration Risk [Member] | Revenue from Contract with Customer, Product and Service Benchmark [Member] | Customer A [Member]
Concentration Risk [Line Items]
Concentration risk percentage (as a percent)		20.00%	17.00%	21.00%
Customer Concentration Risk [Member] | Revenue from Contract with Customer, Product and Service Benchmark [Member] | Customer B [Member]
Concentration Risk [Line Items]
Concentration risk percentage (as a percent)	23.00%		12.00%

Organization and Summary of _15

Organization and Summary of Significant Accounting Policies - Concentrations Risk - Accounts Receivable (Details)	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Customer Concentration Risk [Member] | Accounts Receivable [Member] | Customer B [Member]
Concentration Risk [Line Items]
Concentration risk percentage (as a percent)	28.00%	13.00%

Organization and Summary of _16

Organization and Summary of Significant Accounting Policies - Recent Accounting Pronouncements (Details)	Sep. 30, 2019
Accounting Standards Update 2018-13 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Change in Accounting Principle, Accounting Standards Update, Adopted	false
Change in Accounting Principle, Accounting Standards Update, Early Adoption	false
Accounting Standards Update 2017-04 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Change in Accounting Principle, Accounting Standards Update, Adopted	false
Change in Accounting Principle, Accounting Standards Update, Early Adoption	false
Accounting Standards Update 2016-13 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Change in Accounting Principle, Accounting Standards Update, Adopted	false
Change in Accounting Principle, Accounting Standards Update, Early Adoption	false
Accounting Standards Update 2016-02 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Change in Accounting Principle, Accounting Standards Update, Adopted	true
Change in Accounting Principle, Accounting Standards Update, Adoption Date	Jan. 1, 2019
Change in Accounting Principle, Accounting Standards Update, Early Adoption	false
Change in Accounting Principle, Accounting Standards Update, Transition Option Elected	Modified Retrospective

Acquisitions - General Informat

Acquisitions - General Information (Details)	Sep. 14, 2018	May 09, 2018
Echelon Corporation [Member]
Business Acquisition, Date of Acquisition [Abstract]
Date of Acquisition	Sep. 14, 2018
Business Combination, Description [Abstract]
Percentage of issued capital acquired (as a percent)	100.00%
S3 Asic Semiconductors Limited [Member]
Business Acquisition, Date of Acquisition [Abstract]
Date of Acquisition		May 9, 2018
Business Combination, Description [Abstract]
Percentage of issued capital acquired (as a percent)		100.00%

Acquisitions - Consideration Tr

Acquisitions - Consideration Transferred (Details) - USD ($) $ in Millions	Sep. 14, 2018	May 09, 2018
Echelon Corporation [Member]
Business Combination, Consideration Transferred [Abstract]
Cash consideration	$ 44.1
Aggregate consideration	$ 44.1
S3 Asic Semiconductors Limited [Member]
Business Combination, Consideration Transferred [Abstract]
Aggregate consideration		$ 35
Earn-out		$ 15

Acquisitions - Fair Values of A

Acquisitions - Fair Values of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018	Sep. 14, 2018	May 09, 2018
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Goodwill	$ 38,640	$ 38,640
Echelon Corporation [Member]
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Cash			$ 15,270
Short term investments			1,274
Accounts receivable			3,020
Inventories			5,710
Other current assets			2,845
Property and equipment, net			614
Intangible assets			17,690
Goodwill			4,266
Other non-current assets			252
Accounts payable			(3,630)
Other current liabilities			(2,642)
Other non-current liabilities			(563)
Fair value of net assets acquired			$ 44,106
S3 Asic Semiconductors Limited [Member]
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Cash				$ 267
Accounts receivable				192
Other current assets				883
Property and equipment, net				191
Intangible assets				15,340
Goodwill				34,352
Accounts payable				(37)
Deferred revenue				(129)
Earn-out liability, current				(10,218)
Other current liabilities				(761)
Deferred tax liability				(1,918)
Earn-out liability, non-current				(3,279)
Fair value of net assets acquired				$ 34,883

Acquisitions - Intangible Asset

Acquisitions - Intangible Assets (Details) - USD ($) $ in Thousands	Sep. 14, 2018	May 09, 2018	Sep. 30, 2019	Dec. 31, 2018
Echelon Corporation [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets acquired	$ 17,690
Echelon Corporation [Member] | Customer Relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets acquired	$ 6,520
Intangible assets, estimated useful life	7 years
Echelon Corporation [Member] | Developed Technology Rights [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets acquired	$ 10,670
Intangible assets, estimated useful life	4 years
Echelon Corporation [Member] | Trademarks [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets acquired	$ 500
Intangible assets, estimated useful life	8 years
S3 Asic Semiconductors Limited [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets acquired		$ 15,340
S3 Asic Semiconductors Limited [Member] | Customer Relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets acquired		$ 12,880
Intangible assets, estimated useful life		7 years
S3 Asic Semiconductors Limited [Member] | Order or Production Backlog [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets acquired		$ 210
Intangible assets, estimated useful life		6 months	6 months	6 months
S3 Asic Semiconductors Limited [Member] | Developed Technology Rights [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets acquired		$ 1,080
Intangible assets, estimated useful life		5 years
S3 Asic Semiconductors Limited [Member] | Non-compete Agreements [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets acquired		$ 380
Intangible assets, estimated useful life		2 years
S3 Asic Semiconductors Limited [Member] | Trademarks [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets acquired		$ 790
Intangible assets, estimated useful life		12 years

Balance Sheet Components - Acco

Balance Sheet Components - Accounts Receivable, Net (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Accounts Receivable, Net, Current [Abstract]
Accounts receivable	$ 30,110	$ 22,490
Accounts receivable, unbilled	3,863	751
Allowance for doubtful accounts	(60)	(30)
Total accounts receivable, net	$ 33,913	$ 23,211

Balance Sheet Components - Inve

Balance Sheet Components - Inventories - Tabular Disclosure (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Inventory, Net [Abstract]
Raw materials	$ 2,213	$ 1,427
Work-in-process	8,019	11,451
Finished goods	6,111	5,757
Total inventories	$ 16,343	$ 18,635

Balance Sheet Components - In_2

Balance Sheet Components - Inventories - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Balance Sheet Related Disclosures [Abstract]
Inventory write-downs		$ 16	$ 300
Realized benefit from sales of previously reserved products	$ 300			$ 900

Balance Sheet Components - Prop

Balance Sheet Components - Property and Equipment - Tabular Disclosure (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Property Plant And Equipment [Line Items]
Property and equipment, at cost	$ 26,931	$ 24,143
Accumulated depreciation and amortization	(18,891)	(17,058)
Property and equipment, net	8,040	7,085
Machinery and Equipment [Member]
Property Plant And Equipment [Line Items]
Property and equipment, at cost	17,136	15,537
Leasehold Improvements [Member]
Property Plant And Equipment [Line Items]
Property and equipment, at cost	4,418	4,422
Software and Software Development Costs [Member]
Property Plant And Equipment [Line Items]
Property and equipment, at cost	4,328	3,760
Furniture and Fixtures [Member]
Property Plant And Equipment [Line Items]
Property and equipment, at cost	934	372
Construction in Progress [Member]
Property Plant And Equipment [Line Items]
Property and equipment, at cost	$ 115	$ 52

Balance Sheet Components - Pr_2

Balance Sheet Components - Property and Equipment - Useful Lives (Details)	9 Months Ended
	Sep. 30, 2019
Tools, Dies and Molds [Member]
Property Plant And Equipment [Line Items]
Property and equipment, estimated useful lives	3 years

Balance Sheet Components - Pr_3

Balance Sheet Components - Property and Equipment - Depreciation and Amortization (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Balance Sheet Related Disclosures [Abstract]
Depreciation and amortization	$ 900	$ 600	$ 2,226	$ 1,687

Balance Sheet Components - Accr

Balance Sheet Components - Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Balance Sheet Related Disclosures [Abstract]
Accrued sales commission payable	$ 260	$ 387
Accrued manufacturing expenses	1,023	692
Liabilities to certain customers		366
Warranty reserve	504	505
Lighting disposal liabilities	1,404
Deferred revenue, current portion	649	1,848
Other accrued liabilities	1,932	1,374
Total accrued expenses and other current liabilities	$ 5,772	$ 5,172

Fair Value Measurements - Finan

Fair Value Measurements - Financial Assets and Liabilities Measured at Fair Value (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Assets, Fair Value Disclosure [Abstract]
Debt securities, available-for-sale, type	us-gaap:USTreasuryAndGovernmentMember	us-gaap:USTreasuryAndGovernmentMember
Fair Value, Measurements, Recurring [Member]
Assets, Fair Value Disclosure [Abstract]
Debt securities, available-for-sale	$ 300	$ 1,282
Assets, Fair Value Disclosure, Total	760	1,740
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Earn-out liability	10,130	10,450
Fair Value, Measurements, Recurring [Member] | Money Market Funds [Member]
Assets, Fair Value Disclosure [Abstract]
Cash and cash equivalents, fair value disclosure	460	458
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Assets, Fair Value Disclosure [Abstract]
Debt securities, available-for-sale	300	1,282
Assets, Fair Value Disclosure, Total	760	1,740
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Money Market Funds [Member]
Assets, Fair Value Disclosure [Abstract]
Cash and cash equivalents, fair value disclosure	460	458
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Earn-out liability	$ 10,130	$ 10,450

Fair Value Measurements - Earn-

Fair Value Measurements - Earn-out Liability - General Information (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Valuation Technique and Input, Description [Abstract]
Earn-out liability, valuation technique	us-gaap:IncomeApproachValuationTechniqueMember	us-gaap:IncomeApproachValuationTechniqueMember
Fair Value, Measurements, Recurring [Member]
Valuation Technique and Input, Description [Abstract]
Earn-out liability	$ 10,130	$ 10,450

Fair Value Measurements - Ear_2

Fair Value Measurements - Earn-out Liability - Roll Forward (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2019USD ($)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$ 10,450
Change in fair value	(320)
Ending balance	$ 10,130

Intangible Assets, net - Acquis

Intangible Assets, net - Acquisitions (Details) - USD ($) $ in Thousands	Sep. 14, 2018	May 09, 2018	Sep. 28, 2012
Certain Flash Memory Product Assets from Atmel Corporation [Member]
Finite Lived Intangible Assets [Line Items]
Finite-lived intangible assets acquired			$ 16,400
S3 Asic Semiconductors Limited [Member]
Finite Lived Intangible Assets [Line Items]
Finite-lived intangible assets acquired		$ 15,340
Echelon Corporation [Member]
Finite Lived Intangible Assets [Line Items]
Finite-lived intangible assets acquired	$ 17,690

Intangible Assets, net - Estima

Intangible Assets, net - Estimated Useful Life (Details)	May 09, 2018	Sep. 30, 2019	Dec. 31, 2018
Developed Technology Rights [Member] | S3 Asic Semiconductors Limited [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets, estimated useful life	5 years
Developed Technology Rights [Member] | Minimum
Finite Lived Intangible Assets [Line Items]
Intangible assets, estimated useful life		4 years	4 years
Developed Technology Rights [Member] | Maximum
Finite Lived Intangible Assets [Line Items]
Intangible assets, estimated useful life		10 years	10 years
Customer Relationships [Member] | S3 Asic Semiconductors Limited [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets, estimated useful life	7 years
Customer Relationships [Member] | Minimum
Finite Lived Intangible Assets [Line Items]
Intangible assets, estimated useful life		7 years	7 years
Customer Relationships [Member] | Maximum
Finite Lived Intangible Assets [Line Items]
Intangible assets, estimated useful life		12 years	12 years
Order or Production Backlog [Member] | Certain Flash Memory Product Assets from Atmel Corporation [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets, estimated useful life		1 year	1 year
Order or Production Backlog [Member] | S3 Asic Semiconductors Limited [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets, estimated useful life	6 months	6 months	6 months
Non-compete Agreements [Member] | S3 Asic Semiconductors Limited [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets, estimated useful life	2 years
Non-compete Agreements [Member] | Minimum
Finite Lived Intangible Assets [Line Items]
Intangible assets, estimated useful life		2 years	2 years
Non-compete Agreements [Member] | Maximum
Finite Lived Intangible Assets [Line Items]
Intangible assets, estimated useful life		5 years	5 years
Trademarks [Member] | S3 Asic Semiconductors Limited [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets, estimated useful life	12 years
Trademarks [Member] | Minimum
Finite Lived Intangible Assets [Line Items]
Intangible assets, estimated useful life		8 years	8 years
Trademarks [Member] | Maximum
Finite Lived Intangible Assets [Line Items]
Intangible assets, estimated useful life		12 years	12 years

Intangible Assets, net - Schedu

Intangible Assets, net - Schedule of Intangible Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Finite Lived Intangible Assets [Line Items]
Gross carrying amount	$ 49,384	$ 49,384
Accumulated amortization	18,488	13,123
Net carrying amount	30,896	36,261
Developed Technology Rights [Member]
Finite Lived Intangible Assets [Line Items]
Gross carrying amount	16,032	16,032
Accumulated amortization	6,076	3,593
Net carrying amount	9,956	12,439
Customer Relationships [Member]
Finite Lived Intangible Assets [Line Items]
Gross carrying amount	28,411	28,411
Accumulated amortization	8,727	6,085
Net carrying amount	19,684	22,326
Order or Production Backlog [Member] | Certain Flash Memory Product Assets from Atmel Corporation [Member]
Finite Lived Intangible Assets [Line Items]
Gross carrying amount	2,779	2,779
Accumulated amortization	2,779	2,779
Order or Production Backlog [Member] | S3 Asic Semiconductors Limited [Member]
Finite Lived Intangible Assets [Line Items]
Gross carrying amount	210	210
Accumulated amortization	210	210
Non-compete Agreements [Member]
Finite Lived Intangible Assets [Line Items]
Gross carrying amount	662	662
Accumulated amortization	541	398
Net carrying amount	121	264
Trademarks [Member]
Finite Lived Intangible Assets [Line Items]
Gross carrying amount	1,290	1,290
Accumulated amortization	155	58
Net carrying amount	$ 1,135	$ 1,232

Intangible Assets, net - Amorti

Intangible Assets, net - Amortization Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Finite Lived Intangible Assets [Line Items]
Amortization expense, acquisition related intangible assets	$ 1,789	$ 1,138	$ 5,365	$ 2,119
Research and Development Expense [Member]
Finite Lived Intangible Assets [Line Items]
Amortization expense, acquisition related intangible assets	828	323	2,484	567
Sales and Marketing [Member]
Finite Lived Intangible Assets [Line Items]
Amortization expense, acquisition related intangible assets	$ 961	$ 815	$ 2,881	$ 1,552

Intangible Assets, net - Esti_2

Intangible Assets, net - Estimated Future Amortization Expense (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
2019 (remaining 3 months)	$ 1,788
2020	7,037
2021	6,962
2022	6,070
2023	3,735
Thereafter	5,304
Net carrying amount	$ 30,896	$ 36,261

Investment in Unconsolidated _2

Investment in Unconsolidated Affiliates (Details) - USD ($) $ in Millions	Jun. 15, 2017	Jun. 30, 2018	Sep. 30, 2019	Dec. 31, 2018
Long-term Investments and Receivables, Net [Abstract]
Notes receivable and accrued interest converted to shares	$ 0.4	$ 0.5
Shares resulting from the conversion of notes receivable and accrued interest (in shares)	233,335	312,076
Semitech Semiconductor Pty Ltd [Member]
Long-term Investments and Receivables, Net [Abstract]
Invested in notes receivable			$ 0.2
Other Noncurrent Assets [Member] | Semitech Semiconductor Pty Ltd [Member]
Long-term Investments and Receivables, Net [Abstract]
Investments in notes receivable			$ 0.6	$ 0.2

Borrowings - Western Alliance B

Borrowings - Western Alliance Bank Term Loan (Details) $ in Thousands	Sep. 29, 2017	Jul. 07, 2016USD ($)installment	May 31, 2018USD ($)	Sep. 30, 2019USD ($)	Sep. 30, 2018USD ($)
Debt Instrument [Line Items]
Amortization of debt discount and issuance costs				$ 5,149	$ 707
Term loan borrowings repaid				$ 35,492	$ 12,000
Western Alliance Bank Term Loan [Member]
Debt Instrument [Line Items]
Facility fee		$ 150
Debt instrument diligence fee		25
Debt Instrument additional fee liability		10
Unamortized debt discount		25
Secured Debt [Member] | Western Alliance Bank Term Loan [Member]
Debt Instrument [Line Items]
Aggregate principal amount		$ 18,000
Borrowings mature date		Jun. 30, 2019
Debt instrument, description of payment terms		We made interest-only payments on the Term Loan from July 2016 through September 2016 and began making interest payments and principal payments in 33 equal monthly installments starting October 2016.
Number of monthly installments | installment		33
Term loan borrowings repaid			$ 12,000
Secured Debt [Member] | Western Alliance Bank Term Loan [Member] | Interest Expense [Member]
Debt Instrument [Line Items]
Unamortized debt discount			$ 66
Revolving Credit Facility [Member] | Western Alliance Bank Term Loan [Member]
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity		$ 5,000
Line of credit facility, maximum borrowing capacity as a percentage of eligible accounts receivable		80.00%
Borrowings mature date		Jul. 31, 2018
Prime Rate [Member] | Secured Debt [Member] | Western Alliance Bank Term Loan [Member]
Debt Instrument [Line Items]
Debt instrument, description of variable rate basis	The Term Loan bore interest at a rate per annum equal to the greater of the prime rate or 3.5%	The Term Loan bore interest at a rate per annum equal to the greater of the prime rate or 3.5%
Debt instrument, prime rate, minimum (as a percent)		3.50%
Debt instrument, basis spread on variable rate (as a percent)		0.75%
Prime Rate [Member] | Revolving Credit Facility [Member] | Western Alliance Bank Term Loan [Member]
Debt Instrument [Line Items]
Debt instrument, description of variable rate basis	The Line of Credit bore interest at a rate per annum equal to the greater of the prime rate or 3.5%	The Line of Credit bore interest at a rate per annum equal to the greater of the prime rate or 3.5%
Debt instrument, prime rate, minimum (as a percent)		3.50%
Debt instrument, basis spread on variable rate (as a percent)		0.50%

Borrowings - Tennenbaum Capital

Borrowings - Tennenbaum Capital Partners, LLC Term Loan (Details) - USD ($) $ / shares in Units, $ in Thousands	May 08, 2018	Sep. 30, 2019	Sep. 30, 2018	Sep. 27, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Repayment of borrowings		$ 35,492	$ 12,000
Amortization of debt discount and issuance costs		$ 5,149	707
Common Stock Warrants [Member]
Debt Instrument [Line Items]
Number of shares warrants may purchase (in shares)		1,165,282			1,239,423
Exercise price (in dollars per share)		$ 8.11		$ 30.35	$ 8.11
Common Stock Warrants, Tennenbaum Capital Partners, LLC Warrant [Member]
Debt Instrument [Line Items]
Number of warrants (in shares)	1
Number of shares warrants may purchase (in shares)	850,000	850,000			850,000
Number of shares each warrant may purchase (in shares)	850,000
Exercise price (in dollars per share)	$ 8.30	$ 8.30			$ 8.30
Term of warrant	6 years
Tennenbaum Capital Partners, LLC Term Loan [Member] | Secured Debt [Member]
Debt Instrument [Line Items]
Liable to prepayment premium		$ 700
Tennenbaum Capital Partners, LLC Term Loan [Member] | Secured Debt [Member]
Debt Instrument [Line Items]
Aggregate principal amount	$ 35,000
Borrowings mature date	May 8, 2022
Debt instrument, interest rate spread above otherwise applicable interest rate (as a percent)	2.00%
Financing costs paid	$ 1,400
Unamortized debt discount	$ 4,800
Repayment of borrowings		33,800
Amortization of debt discount and issuance costs		$ 5,100	$ 700
Tennenbaum Capital Partners, LLC Term Loan [Member] | Secured Debt [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate (as a percent)	8.75%

Borrowings - Outstanding Borrow

Borrowings - Outstanding Borrowings (Details) $ in Thousands	Dec. 31, 2018USD ($)
Long-term Debt, Unclassified [Abstract]
Term loan, current	$ 141
Term loan, non-current	$ 29,418

Borrowings - Interest Expense (

Borrowings - Interest Expense (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Interest Expense, Debt [Abstract]
Interest expense (excluding unamortized discount)	$ 6	$ 8.8	$ 1.1	$ 2.4

Convertible Senior Notes (Detai

Convertible Senior Notes (Details) $ in Thousands	Sep. 23, 2019USD ($)shares	Sep. 30, 2019USD ($)$ / item	Sep. 30, 2018USD ($)	Sep. 30, 2019USD ($)$ / item	Sep. 30, 2018USD ($)
Debt Instrument [Line Items]
Provision for (benefit from) income taxes		$ 337	$ (64)	$ 236	$ (80)
Initial strike price of Capped Calls | $ / item		12		12
Cap price of Capped Calls | $ / item		15.86		15.86
Premium paid for purchase of Capped Calls				$ 6,200
Convertible Notes Payable [Member]
Debt Instrument [Line Items]
Aggregate principal amount	$ 80,500
Interest rate (as percentage)	4.25%
Implied estimated effective rate	12.30%
Number of shares per $1,000 principal amount of Notes | shares	83.3021
Notes at fair value	$ 57,900
Capital in excess of Par Value	22,600	$ 21,662		21,662
Initial purchasers discount	3,220
Other costs	300
Issuance costs	3,500
Issuance costs relating to Additional Paid-In Capital	1,000	$ (987)		$ (987)
Convertible senior notes	$ 2,500
Percentage of aggregate principal amount of outstanding of notes due and payable	25
Scenario, One [Member] | Convertible Notes Payable [Member] | Minimum
Debt Instrument [Line Items]
Number of trading days	20 days
Percentage of conversion price	130
Scenario, One [Member] | Convertible Notes Payable [Member] | Maximum
Debt Instrument [Line Items]
Total number of trading days	30 days
Scenario, Two [Member] | Convertible Notes Payable [Member] | Minimum
Debt Instrument [Line Items]
Number of trading days	5 days
Scenario, Two [Member] | Convertible Notes Payable [Member] | Maximum
Debt Instrument [Line Items]
Total number of trading days	10 days
Percentage of conversion price	98

Convertible Senior Notes - equi

Convertible Senior Notes - equity and liability components (Details) - Convertible Notes Payable [Member] - USD ($) $ in Thousands	Sep. 30, 2019	Sep. 23, 2019
Debt Instrument [Line Items]
Principal amount of 2024 Notes outstanding	$ 57,851
Unamortized discount (including unamortized debt issuance cost)	(2,536)
Total long-term portion of notes payable	55,315
Equity component of notes	22,649
Less: Issuance costs	(987)	$ 1,000
Capital in excess of Par Value	$ 21,662	$ 22,600

Segment Information - General I

Segment Information - General Information (Details) - segment	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting [Abstract]
Number of business segments	1	1	1	1

Segment Information - Revenue b

Segment Information - Revenue by Geographic Region (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue, net	$ 32,028	$ 21,927	$ 90,297	$ 55,412
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue, net	8,648	7,253	24,310	15,472
Rest of Americas [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue, net	1,015	583	4,608	868
Europe [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue, net	6,085	5,087	16,989	11,708
Asia Pacific [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue, net	15,905	8,865	43,502	27,078
Rest of World [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue, net	$ 375	$ 139	$ 888	$ 286

Segment Information - Long-Live

Segment Information - Long-Lived Assets by Geographic Region - Property and Equipment, Net (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	$ 8,040	$ 7,085
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	3,415	3,879
Asia Pacific [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	3,868	2,968
Europe [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	$ 757	$ 238

Segment Information - Long-Li_2

Segment Information - Long-Lived Assets by Geographic Region - Right-of-use Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Jan. 01, 2019
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating lease right-of-use assets	$ 4,474	$ 4,877
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating lease right-of-use assets	2,165
Asia Pacific [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating lease right-of-use assets	199
Europe [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating lease right-of-use assets	$ 2,110

Commitments and Contingencies -

Commitments and Contingencies - Operating Leases - Lease Assets and Lease Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Jan. 01, 2019
Assets and Liabilities, Lessee [Abstract]
Operating lease right-of-use assets	$ 4,474	$ 4,877
Operating lease liabilities, current	1,186	1,116
Operating lease liabilities, non-current	$ 5,048	$ 5,917

Commitments and Contingencies_2

Commitments and Contingencies - Operating Leases - Lease Cost (Details) $ in Thousands	3 Months Ended
	Sep. 30, 2019USD ($)
Lease, Cost [Abstract]
Operating lease cost	$ 1,626

Commitments and Contingencies_3

Commitments and Contingencies - Operating Leases - Maturity of Operating Lease Liabilities (Details) $ in Thousands	Sep. 30, 2019USD ($)
Maturity of operating lease liabilities
2019 (remaining 3 months)	$ 519
2020	1,962
2021	1,734
2022	1,569
2023	1,021
Thereafter	2,235
Total lease payments	$ 9,040

Commitments and Contingencies_4

Commitments and Contingencies - Operating Leases - Present Value of Lease Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Jan. 01, 2019
Operating Lease Liabilities, Gross Difference, Amount [Abstract]
Total lease payments	$ 9,040
Less: Interest	(2,806)
Present value of lease liabilities	$ 6,234	$ 7,000

Commitments and Contingencies_5

Commitments and Contingencies - Operating Leases - Lease Term and Discount Rate (Details)	Sep. 30, 2019
Lessee Disclosure [Abstract]
Weighted-average remaining lease term (in years)	7 years 2 months 12 days
Weighted-average discount rate	11.56%

Commitments and Contingencies_6

Commitments and Contingencies - Operating Leases - Other Information (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2019USD ($)
Lessee Disclosure [Abstract]
Operating cash outflows from operating leases	$ 1,626
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 0

Commitments and Contingencies_7

Commitments and Contingencies - Purchase Commitments (Details) $ in Millions	Sep. 30, 2019USD ($)
Purchase Commitments with Third-party Foundries [Member]
Purchase Commitment, Excluding Long-term Commitment [Line Items]
Purchase commitments	$ 5

Common Stock, Common Stock Wa_3

Common Stock, Common Stock Warrants and Stock Option Plan - Common Stock (Details)	9 Months Ended		12 Months Ended
	Sep. 30, 2019Vote$ / sharesshares	Sep. 30, 2018$ / shares	Dec. 31, 2018Vote$ / sharesshares
Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Common stock, shares authorized (in shares) | shares	100,000,000		100,000,000
Common stock, par value (in dollars per share)	$ 0.0001		$ 0.0001
Voting right common stock holder	Each holder of common stock is entitled to one vote per share.		Each holder of common stock is entitled to one vote per share.
Common stock, votes per share (in votes) | Vote	1		1
Common stock, dividends declared	$ 0	$ 0

Common Stock, Common Stock Wa_4

Common Stock, Common Stock Warrants and Stock Option Plan - Public Offering (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended
	Jul. 31, 2018	Jun. 30, 2017
Follow-on Offering [Member]
Subsidiary, Sale of Stock [Line Items]
Stock issued (in shares)	7,705,000	5,000,000
Share price (in dollars per share)	$ 6	$ 4
Proceeds from public offering, net of underwriting discounts and commissions	$ 42.7	$ 18.4
Over-Allotment Option [Member]
Subsidiary, Sale of Stock [Line Items]
Stock issued (in shares)	1,005,000	625,000

Common Stock, Common Stock Wa_5

Common Stock, Common Stock Warrants and Stock Option Plan - Stock Reserved for Future Issuance (Details) - shares	Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2015
Class of Stock [Line Items]
Common stock, capital shares reserved for future issuance (in shares)	14,260,159	4,719,271
Convertible Notes Payable [Member]
Class of Stock [Line Items]
Common stock, capital shares reserved for future issuance (in shares)	8,885,204
Share-based Payment Arrangement, Option [Member]
Class of Stock [Line Items]
Common stock, capital shares reserved for future issuance (in shares)	1,958,989	1,865,415
Restricted Stock Units (RSUs) [Member]
Class of Stock [Line Items]
Common stock, capital shares reserved for future issuance (in shares)	1,617,258	1,154,980
Shares available for future grants (in shares)	259,998	96,515
Employee Stock [Member]
Class of Stock [Line Items]
Common stock, capital shares reserved for future issuance (in shares)	373,428	362,938	150,000
Common Stock Warrants [Member]
Class of Stock [Line Items]
Warrants to purchase common stock (in shares)	1,165,282	1,239,423

Common Stock, Common Stock Wa_6

Common Stock, Common Stock Warrants and Stock Option Plan - Common Stock Warrants - Warrant Issued (Details) - USD ($) $ / shares in Units, $ in Millions	Sep. 30, 2019	Dec. 31, 2018	May 08, 2018
Tennenbaum Capital Partners, LLC Term Loan [Member] | Secured Debt [Member]
Class of Warrant or Right [Line Items]
Unamortized debt discount			$ 4.8
Common Stock Warrants, Tennenbaum Capital Partners, LLC Warrant [Member]
Class of Warrant or Right [Line Items]
Number of warrants (in shares)			1
Number of shares warrants may purchase (in shares)	850,000	850,000	850,000
Number of shares each warrant may purchase (in shares)			850,000
Exercise price (in dollars per share)	$ 8.30	$ 8.30	$ 8.30
Term of warrant			6 years

Common Stock, Common Stock Wa_7

Common Stock, Common Stock Warrants and Stock Option Plan - Common Stock Warrants - Fair Value Measurement Inputs (Details) - Common Stock Warrants, Tennenbaum Capital Partners, LLC Warrant [Member]	May 08, 2018Y$ / shares
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants, valuation technique	us-gaap:ValuationTechniqueOptionPricingModelMember
Measurement Input, Share Price [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants, measurement input | $ / shares	8.70
Measurement Input, Expected Dividend Rate [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants, measurement input	0
Measurement Input, Price Volatility [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants, measurement input	0.6973
Measurement Input, Risk Free Interest Rate [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants, measurement input	0.0287
Measurement Input, Expected Term [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants, measurement input | Y	6

Common Stock, Common Stock Wa_8

Common Stock, Common Stock Warrants and Stock Option Plan - Common Stock Warrants - Tabular Disclosure (Details) - $ / shares	Sep. 30, 2019	Sep. 27, 2019	Dec. 31, 2018	May 08, 2018
Common Stock Warrants [Member]
Class of Warrant or Right [Line Items]
Warrants to purchase common stock (in shares)	1,165,282		1,239,423
Exercise price of warrant	$ 8.11	$ 30.35	$ 8.11
Common Stock Warrants Three [Member]
Class of Warrant or Right [Line Items]
Warrants to purchase common stock (in shares)	315,282		315,282
Exercise price of warrant	$ 2.38		$ 2.38
Common Stock Warrants, Tennenbaum Capital Partners, LLC Warrant [Member]
Class of Warrant or Right [Line Items]
Warrants to purchase common stock (in shares)	850,000		850,000	850,000
Exercise price of warrant	$ 8.30		$ 8.30	$ 8.30

Common Stock, Common Stock Wa_9

Common Stock, Common Stock Warrants and Stock Option Plan - Common Stock Warrants - Additional Information (Details) - Common Stock Warrants [Member] - USD ($)	Sep. 30, 2019	Sep. 27, 2019	Dec. 31, 2018
Class of Warrant or Right [Line Items]
Unexercised warrants		$ 74,141
Exercise price of warrant	$ 8.11	$ 30.35	$ 8.11

Common Stock, Common Stock W_10

Common Stock, Common Stock Warrants and Stock Option Plan - 2007 Equity Incentive Plan (Details) - shares	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018	Dec. 31, 2015	Oct. 26, 2015	Dec. 31, 2007	Jan. 31, 2007
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock, capital shares reserved for future issuance (in shares)	14,260,159	4,719,271
Share-based Payment Arrangement, Option [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock, capital shares reserved for future issuance (in shares)	1,958,989	1,865,415
2007 Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock, capital shares reserved for future issuance (in shares)			2,651,515		787,878	272,727
Percentage of fair market value of common stock (as a percent)	85.00%
Number of shares available for grant (in shares)				0
2007 Plan [Member] | New Employee [Member] | Share-based Compensation Award, Tranche One [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting percentage (as a percent)	25.00%
2007 Plan [Member] | Share-based Payment Arrangement, Option [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period	4 years
Exercisable period	10 years
2007 Plan [Member] | Restricted Stock [Member] | Persons controlling more than 10% of Company's stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of fair market value of common stock (as a percent)	100.00%

Common Stock, Common Stock W_11

Common Stock, Common Stock Warrants and Stock Option Plan - 2015 Equity Incentive Plan (Details) - shares	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018	Oct. 26, 2015
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock, capital shares reserved for future issuance (in shares)	14,260,159	4,719,271
2015 Equity Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock, capital shares reserved for future issuance (in shares)			1,813,272
Stock option grants description	The number of shares reserved for issuance under our 2015 Equity Incentive Plan will increase automatically on the first day of January of each of 2016 through 2025 by the number of shares equal to 4% of the total outstanding shares of our common stock as of the immediately preceding December 31.
Percentage threshold of outstanding shares increased annually under the plan (as a percent)	4.00%
Incentive stock options, maximum shares that may be issued (in shares)	25,000,000
Existing Employee [Member] | 2015 Equity Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock shares authorized for issuance (in shares)	2,000,000
New Employee [Member] | 2015 Equity Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock shares authorized for issuance (in shares)	4,000,000
Non Employee Director [Member] | 2015 Equity Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock shares authorized for issuance (in shares)	300,000

Common Stock, Common Stock W_12

Common Stock, Common Stock Warrants and Stock Option Plan - 2015 Employee Stock Purchase Plan (Details) - USD ($)	Jul. 31, 2019	Jan. 31, 2019	Jul. 31, 2018	Jan. 31, 2018	Jul. 29, 2016	Sep. 30, 2015	Sep. 30, 2019	Dec. 31, 2017	Dec. 31, 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock, capital shares reserved for future issuance (in shares)							14,260,159		4,719,271
Employee Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock, capital shares reserved for future issuance (in shares)						150,000	373,428		362,938
Employee stock purchase plan description							The number of shares reserved for issuance under our 2015 Employee Stock Purchase Plan will increase automatically on the first day of January following the first offering date by the number of shares equal to 1% of the total outstanding shares of our common stock as of the immediately preceding December 31 (rounded to the nearest whole share).
Percentage threshold of outstanding shares increased annually under the plan (as a percent)						1.00%
Common stock shares authorized for issuance (in shares)						2,250,000
Payroll deduction (as a percent)							15.00%
Percentage of fair market value of common stock (as a percent)							85.00%
Shares issued (in shares)	154,116	129,815	69,761	55,806	68,392			110,711
Maximum fair market value, that would permit employee to purchase common stock under plan							$ 25,000
Maximum number of shares issued each participants (in shares)							2,500

Common Stock, Common Stock W_13

Common Stock, Common Stock Warrants and Stock Option Plan - Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Shares
Outstanding, beginning of period (in shares)		1,865,415	1,560,453	991,895
Granted (in shares)	0	189,856	479,375	835,480
Exercised (in shares)		(91,173)	(112,965)	(230,123)
Cancelled (in shares)		(5,109)	(61,448)	(36,799)
Outstanding, end of period (in shares)	1,958,989	1,958,989	1,865,415	1,560,453	991,895
Weighted Average Exercise Price
Outstanding, beginning of period (in dollars per share)		$ 4.63	$ 3.63	$ 2.68
Granted (in dollars per share)		6.16	7.25	4.30
Exercised (in dollars per share)		3.16	2.48	1.92
Cancelled (in dollars per share)		7.26	3.65	4.16
Outstanding, end of period (in dollars per share)	$ 4.84	$ 4.84	$ 4.63	$ 3.63	$ 2.68
Additional information
Weighted Average Remaining Contractual Term (Years)		7 years 2 months 12 days	7 years 7 months 6 days	7 years 7 months 6 days	6 years 3 months 18 days
Aggregate Intrinsic Value	$ 7,371	$ 7,371	$ 1,540	$ 4,632	$ 161
Options vested and exercisable, end of period (in shares)	1,137,160	1,137,160
Options vested and exercisable, end of period (in dollars per share)	$ 4.08	$ 4.08
Options vested and exercisable		6 years 4 months 24 days
Options vested and exercisable as of June 30, 2018	$ 5,173	$ 5,173
Vested and expected to vest
Options vested and expected to vest, end of period (in shares)	1,903,094	1,903,094
Options vested and expected to vest, end of period (in dollars per share)	$ 4.80	$ 4.80
Options vested and expected to vest		7 years 2 months 12 days
Options vested and expected to vest as of June 30, 2018	$ 7,241	$ 7,241

Common Stock, Common Stock W_14

Common Stock, Common Stock Warrants and Stock Option Plan - Restricted Stock Units - Activity (Details) - Restricted Stock Units (RSUs) [Member] - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Shares
Outstanding, beginning of period (in shares)	1,154,980	509,894	490,954
Granted (in shares)	965,313	925,578	541,513
Released (in shares)	(361,742)	(264,568)	(497,009)
Forfeited/expired (in shares)	(141,293)	(15,924)	(25,564)
Outstanding, end of period (in shares)	1,617,258	1,154,980	509,894	490,954
Weighted Average Grant Date Fair Value
Outstanding, beginning of period (in dollars per share)	$ 5.50	$ 2.84	$ 5.80
Granted (in dollars per share)	6.33	6.55	2.88
Released (in dollars per share)	5.26	4.02	5.64
Forfeited/expired (in dollars per share)	4.88	8.34	5.98
Outstanding, end of period (in dollars per share)	$ 6.10	$ 5.50	$ 2.84	$ 5.80
Weighted Average Remaining Contractual Term (Years)
Weighted Average Remaining Contractual Term (Years)	1 year 4 months 24 days	1 year 4 months 24 days	1 year 4 months 24 days	6 months
Aggregate Intrinsic Value
Outstanding, end of period	$ 13,844	$ 5,082	$ 3,288	$ 908

Stock-based Compensation - Gene

Stock-based Compensation - General Information (Details)	3 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Employee's requisite service period		4 years
Share-based Payment Arrangement, Option [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected dividend yield (as a percent)	0.00%	0.00%	0.00%

Stock-based Compensation - Weig

Stock-based Compensation - Weighted Average Assumptions Used to Value Options (Details) - Share-based Payment Arrangement, Option [Member]	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Volatility (as a percent)	57.00%	77.00%	65.00%	72.00%
Expected dividend yield (as a percent)		0.00%	0.00%	0.00%
Risk-free rate (as a percent)	1.90%	2.80%	2.22%	2.84%
Expected term (in years)	6 years	5 years	6 years	6 years

Stock-based Compensation - Opti

Stock-based Compensation - Options Granted and Weighted Average Grant Date Fair Value of Options Granted (Details) - $ / shares	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Weighted-average grant date fair value of the options granted (in dollars per share)	$ 4.40	$ 3.68
Options granted (in shares)	0	189,856	479,375	835,480

Stock-based Compensation - Perf

Stock-based Compensation - Performance-based RSUs (Details) - $ / shares	Mar. 25, 2019	Apr. 01, 2018	Apr. 01, 2017	Sep. 30, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Restricted Stock Units (RSUs) [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Granted (in shares)				965,313	925,578	541,513
Fair value per share at the time of grant (in dollars per share)				$ 6.33	$ 6.55	$ 2.88
Outstanding units, nonvested (in shares)				1,617,258	1,154,980	509,894	490,954
Performance Shares [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Granted (in shares)	147,954	102,283	204,220
Vesting period	1 year	1 year	1 year
Fair value per share at the time of grant (in dollars per share)	$ 4.05	$ 4.92	$ 0.81
Expected term (in years)	3 years
Performance Shares [Member] | Share-based Compensation Award, Tranche One [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting percentage (as a percent)	20.00%	20.00%
Performance Shares [Member] | Share-based Payment Arrangement, Tranche Two [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period	2 years
Vesting percentage (as a percent)	80.00%	80.00%

Stock-based Compensation - Shar

Stock-based Compensation - Share-based Compensation (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	$ 1,635	$ 940	$ 4,074	$ 2,103
Cost of Sales [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	80	56	212	129
Research and Development Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	638	356	1,517	786
Selling, General and Administrative Expenses [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	$ 917	$ 528	$ 2,345	$ 1,188

Stock-based Compensation - Unre

Stock-based Compensation - Unrecognized Compensation Cost (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2019USD ($)
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized [Abstract]
Unrecognized compensation cost, options	$ 2,600
Share-based Payment Arrangement, Option [Member]
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized [Abstract]
Expected to be recognized over a weighted-average period	2 years 2 months 12 days
Restricted Stock Units (RSUs) [Member]
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized [Abstract]
Unrecognized compensation cost, excluding options	$ 7,900
Expected to be recognized over a weighted-average period	2 years 4 months 24 days
Employee Stock [Member]
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized [Abstract]
Unrecognized compensation cost, excluding options	$ 163
Expected to be recognized over a weighted-average period	3 months 18 days

Income Taxes - Provision (Detai

Income Taxes - Provision (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Tax Disclosure [Abstract]
Benefit from income tax	$ 337	$ (64)	$ 236	$ (80)

Income Taxes - Rate (Details)

Income Taxes - Rate (Details)	9 Months Ended		12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Federal tax at statutory rate (as a percent)	21.00%	21.00%	35.00%

Net Loss Per Share (Details)

Net Loss Per Share (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	11,447,348	4,157,646	11,447,348	4,157,646
Share-based Payment Arrangement, Option [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	1,958,989	1,844,030	1,958,989	1,844,030
Restricted Stock Units (RSUs) [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	1,617,258	1,074,193	1,617,258	1,074,193
Convertible Debt Securities [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	6,705,819		6,705,819
Common Stock Warrants [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	1,165,282	1,239,423	1,165,282	1,239,423

Related Party Transactions (Det

Related Party Transactions (Details) - USD ($) $ in Thousands	9 Months Ended		10 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Jun. 30, 2019	Dec. 31, 2018	Sep. 14, 2018
Related Party Transaction [Line Items]
Payments to related party	$ 0	$ 0
Accounts payable to related party	0			$ 0
Revenue from related parties			$ 600
Accounts receivable from related party	$ 12
Echelon Corporation [Member]
Related Party Transaction [Line Items]
Percentage of issued capital acquired (as a percent)					100.00%

Restructuring (Details)

Restructuring (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2019USD ($)
Restructuring Charges [Abstract]
Restructuring expense	$ 1,694
Closing of Lighting Business [Member]
Restructuring Charges [Abstract]
Restructuring expense	$ 1,700