Power Integrations (POWI) 10-K 12 Feb 24 2023 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ / shares in Units, shares in Thousands, $ in Billions	12 Months Ended
	Dec. 31, 2023	Feb. 05, 2024	Jun. 30, 2023
Document and Entity Information
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2023
Document Transition Report	false
Entity File Number	000-23441
Entity Registrant Name	POWER INTEGRATIONS, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	94-3065014
Entity Address, Address Line One	5245 Hellyer Avenue
Entity Address, City or Town	San Jose
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	95138-1002
City Area Code	408
Local Phone Number	414-9200
Title of 12(b) Security	Common Stock
Trading Symbol	POWI
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Document Financial Statement Error Correction	false
Entity Shell Company	false
Entity Public Float			$ 4.1
Entity Common Stock, Shares Outstanding		56,886
Entity Listing, Par Value Per Share	$ 0.001
Entity Central Index Key	0000833640
Current Fiscal Year End Date	--12-31
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2023
Amendment Flag	false
Auditor Name	DELOITTE & TOUCHE LLP
Auditor Location	San Jose, California
Auditor Firm ID	34

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
CURRENT ASSETS:
Cash and cash equivalents	$ 63,929	$ 105,372
Short-term marketable securities	247,640	248,441
Accounts receivable, net	14,674	20,836
Inventories	163,164	135,420
Prepaid expenses and other current assets	22,193	15,004
Total current assets	511,600	525,073
PROPERTY AND EQUIPMENT, net	164,213	176,681
INTANGIBLE ASSETS, net	4,424	6,597
GOODWILL	91,849	91,849
DEFERRED TAX ASSETS	28,325	19,034
OTHER ASSETS	19,457	20,862
Total assets	819,868	840,096
CURRENT LIABILITIES:
Accounts payable	26,390	30,088
Accrued payroll and related expenses	13,551	14,778
Taxes payable	1,016	938
Other accrued liabilities	7,910	12,572
Total current liabilities	48,867	58,376
LONG-TERM INCOME TAXES PAYABLE	6,244	15,757
OTHER LIABILITIES	12,516	10,747
Total liabilities	67,627	84,880
COMMITMENTS AND CONTINGENCIES (Notes 11, 12 and 13)
STOCKHOLDERS' EQUITY:
Common stock, $0.001 par value, Authorized - 140,000 shares, Outstanding - 56,738 and 56,961 shares in 2023 and 2022, respectively	23	24
Additional paid-in capital	0	0
Accumulated other comprehensive loss	(1,462)	(7,344)
Retained earnings	753,680	762,536
Total stockholders' equity	752,241	755,216
Total liabilities and stockholders' equity	$ 819,868	$ 840,096

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares shares in Thousands	Dec. 31, 2023	Dec. 31, 2022
CONSOLIDATED BALANCE SHEETS
Common stock, par value per share	$ 0.001	$ 0.001
Common stock, shares authorized	140,000	140,000
Common stock, shares outstanding	56,738	56,961

CONSOLIDATED STATEMENTS OF INCO

CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
CONSOLIDATED STATEMENTS OF INCOME
NET REVENUES	$ 444,538	$ 651,138	$ 703,277
COST OF REVENUES	215,582	284,231	342,638
GROSS PROFIT	228,956	366,907	360,639
OPERATING EXPENSES:
Research and development	96,067	93,894	84,933
Sales and marketing	64,598	62,574	60,808
General and administrative	33,232	28,897	39,840
Other operating expenses, net	0	1,130	0
Total operating expenses	193,897	186,495	185,581
INCOME FROM OPERATIONS	35,059	180,412	175,058
OTHER INCOME	10,848	3,014	1,077
INCOME BEFORE INCOME TAXES	45,907	183,426	176,135
PROVISION (BENEFIT) FOR INCOME TAXES	(9,828)	12,575	11,722
NET INCOME	$ 55,735	$ 170,851	$ 164,413
EARNINGS PER SHARE:
Basic (in dollars per share)	$ 0.97	$ 2.96	$ 2.73
Diluted (in dollars per share)	$ 0.97	$ 2.93	$ 2.67
SHARES USED IN PER SHARE CALCULATION:
Basic (in shares)	57,195	57,801	60,327
Diluted (in shares)	57,622	58,371	61,467

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME
Net income	$ 55,735	$ 170,851	$ 164,413
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments, net of $0 tax in 2023, 2022 and 2021	(420)	(985)	(486)
Unrealized gain (loss) on marketable securities, net of $0 tax in 2023, 2022 and 2021	5,579	(4,158)	(2,055)
Unrealized actuarial gain on pension benefits, net of tax of ($130), ($271) and ($334) in 2023, 2022 and 2021, respectively	723	1,536	967
Total other comprehensive income (loss)	5,882	(3,607)	(1,574)
TOTAL COMPREHENSIVE INCOME	$ 61,617	$ 167,244	$ 162,839

CONSOLIDATED STATEMENTS OF CO_2

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME
Foreign currency translation adjustments, tax	$ 0	$ 0	$ 0
Unrealized gain (loss) on marketable securities, tax	0	0	0
Unrealized actuarial gain on pension benefits, tax	$ (130)	$ (271)	$ (334)

CONSOLIDATED STATEMENTS OF STOC

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Loss	Retained Earnings	Total
Beginning Balance (in shares) at Dec. 31, 2020	59,910
Beginning balance at Dec. 31, 2020	$ 28	$ 190,920	$ (2,163)	$ 621,626	$ 810,411
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock under employee stock option and stock award plans (in shares)	780
Issuance of common stock under employee stock option and stock award plans		1,644			1,644
Repurchase of common stock (in shares)	(878)
Repurchase of common stock	$ (1)	(73,937)			(73,938)
Issuance of common stock under employee stock purchase plan (in shares)	101
Issuance of common stock under employee stock purchase plan	$ 1	6,065			6,066
Stock-based compensation expense related to employee stock options and awards		35,647			35,647
Stock-based compensation expense related to employee stock purchases		1,962			1,962
Payment of dividends to stockholders				(32,599)	(32,599)
Unrealized actuarial gain on pension benefits			967		967
Unrealized gain (loss) on marketable securities			(2,055)		(2,055)
Foreign currency translation adjustment			(486)		(486)
Net income				164,413	164,413
Ending Balance (in shares) at Dec. 31, 2021	59,913
Ending balance at Dec. 31, 2021	$ 28	162,301	(3,737)	753,440	912,032
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock under employee stock option and stock award plans (in shares)	731
Issuance of common stock under employee stock option and stock award plans		257			257
Repurchase of common stock (in shares)	(3,770)
Repurchase of common stock	$ (4)	(190,827)		(120,263)	(311,094)
Issuance of common stock under employee stock purchase plan (in shares)	87
Issuance of common stock under employee stock purchase plan		5,905			5,905
Stock-based compensation expense related to employee stock options and awards		20,494			20,494
Stock-based compensation expense related to employee stock purchases		1,870			1,870
Payment of dividends to stockholders				(41,492)	(41,492)
Unrealized actuarial gain on pension benefits			1,536		1,536
Unrealized gain (loss) on marketable securities			(4,158)		(4,158)
Foreign currency translation adjustment			(985)		(985)
Net income				170,851	170,851
Ending Balance (in shares) at Dec. 31, 2022	56,961
Ending balance at Dec. 31, 2022	$ 24		(7,344)	762,536	755,216
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock under employee stock option and stock award plans (in shares)	476
Repurchase of common stock (in shares)	(784)
Repurchase of common stock	$ (1)	(34,765)		(20,583)	(55,349)
Issuance of common stock under employee stock purchase plan (in shares)	85
Issuance of common stock under employee stock purchase plan		6,237			6,237
Stock-based compensation expense related to employee stock options and awards		26,624			26,624
Stock-based compensation expense related to employee stock purchases		$ 1,904			1,904
Payment of dividends to stockholders				(44,008)	(44,008)
Unrealized actuarial gain on pension benefits			723		723
Unrealized gain (loss) on marketable securities			5,579		5,579
Foreign currency translation adjustment			(420)		(420)
Net income				55,735	55,735
Ending Balance (in shares) at Dec. 31, 2023	56,738
Ending balance at Dec. 31, 2023	$ 23		$ (1,462)	$ 753,680	$ 752,241

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 55,735	$ 170,851	$ 164,413
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	35,203	34,930	31,454
Amortization of intangibles	2,173	2,415	3,494
Loss on disposal of property and equipment	100	1,371	3,105
Stock-based compensation expense	28,528	22,364	37,609
Amortization of premium (accretion of discount) on marketable securities	(351)	3,292	1,590
Deferred income taxes	(9,247)	(2,566)	(13,240)
Increase (decrease) in accounts receivable allowance for credit losses	(454)	690	18
Change in operating assets and liabilities:
Accounts receivable	6,616	19,867	(5,501)
Inventories	(27,744)	(36,154)	3,612
Prepaid expenses and other assets	(1,183)	7,343	4,326
Accounts payable	(5,435)	(3,836)	4,067
Taxes payable and accrued liabilities	(18,182)	(5,224)	(4,079)
Net cash provided by operating activities	65,759	215,343	230,868
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property and equipment	(20,884)	(39,211)	(47,272)
Proceeds from sale of property and equipment	0	1,202	35
Purchases of marketable securities	(191,211)	(55,820)	(554,018)
Proceeds from sales and maturities of marketable securities	197,942	172,165	368,457
Net cash provided by (used in) investing activities	(14,153)	78,336	(232,798)
CASH FLOWS FROM FINANCING ACTIVITIES:
Issuance of common stock under employee stock plans	6,237	6,162	7,710
Repurchase of common stock	(55,278)	(311,094)	(73,938)
Payments of dividends to stockholders	(44,008)	(41,492)	(32,599)
Net cash used in financing activities	(93,049)	(346,424)	(98,827)
NET DECREASE IN CASH AND CASH EQUIVALENTS	(41,443)	(52,745)	(100,757)
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	105,372	158,117	258,874
CASH AND CASH EQUIVALENTS AT END OF PERIOD	63,929	105,372	158,117
SUPPLEMENTAL DISCLOSURE OF NON-CASH INVESTING AND FINANCING ACTIVITIES:
Unpaid property and equipment	2,747	1,082	10,879
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION:
Cash paid for income taxes, net	$ 13,769	$ 17,880	$ 25,644

THE COMPANY

THE COMPANY	12 Months Ended
	Dec. 31, 2023
THE COMPANY
THE COMPANY	1. THE COMPANY: Power Integrations, Inc. (“Power Integrations” or the “Company”), incorporated in California on March 25, 1988, and reincorporated in Delaware in December 1997, designs, develops, manufactures and markets analog and mixed-signal integrated circuits (“ICs”) and other electronic components and circuitry used in high-voltage power conversion. The Company’s products are used in power converters that convert electricity from a high-voltage source to the type of power required for a specified downstream use. In most cases, this conversion entails, among other functions, converting alternating current (“AC”) to direct current (“DC”) or vice versa, reducing or increasing the voltage, and regulating the output voltage and/or current according to the customer’s specifications. ​ A large percentage of the Company’s products are ICs used in AC-DC power supplies, which convert the high-voltage AC from a wall outlet to the low-voltage DC required by most electronic devices. Power supplies incorporating the Company’s products are used with all manner of electronic products including mobile phones, computing and networking equipment, appliances, electronic utility meters, battery-powered tools, industrial controls, and “home-automation,” or “internet of things” applications such as networked thermostats, power strips and other building-automation and security devices. The Company also supplies high-voltage LED drivers, which are AC-DC ICs specifically designed for lighting applications that utilize light-emitting diodes, and motor-drivers ICs for brushless DC (“BLDC”) motors used in consumer appliances, HVAC systems, ceiling fans and a variety of industrial applications. The Company also offers high-voltage gate drivers—either standalone ICs or circuit boards containing ICs, electrical isolation components and other circuitry—used to operate high-voltage switches such as insulated-gate bipolar transistors (“IGBTs”) and silicon-carbide (“SiC”) MOSFETs. These combinations of switches and drivers are used for power conversion in high-power applications (i.e., power levels ranging from approximately 100 kilowatts up to gigawatts) such as industrial motors, solar- and wind-power systems, electric vehicles and high-voltage DC transmission systems.

SIGNIFICANT ACCOUNTING POLICIES

SIGNIFICANT ACCOUNTING POLICIES AND RECENT ACCOUNTING PRONOUNCEMENTS	12 Months Ended
	Dec. 31, 2023
SIGNIFICANT ACCOUNTING POLICIES AND RECENT ACCOUNTING PRONOUNCEMENTS
SIGNIFICANT ACCOUNTING POLICIES AND RECENT ACCOUNTING PRONOUNCEMENTS	2. SIGNIFICANT ACCOUNTING POLICIES AND RECENT ACCOUNTING PRONOUNCEMENTS: Significant Accounting Policies and Estimates Segment Reporting The Company is organized and operates as one reportable segment, the design, development, manufacture and marketing of integrated circuits and related components for use primarily in the high-voltage power conversion markets. The Company’s chief operating decision maker, the Chief Executive Officer, reviews financial information presented on a consolidated basis for purposes of making operating decisions and assessing financial performance. Principles of Consolidation The consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries after elimination of all intercompany transactions and balances. Estimates The preparation of financial statements in conformity with U.S. Generally Accepted Accounting Principles (“GAAP”) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. On an ongoing basis, the Company evaluates its estimates, including those related to revenue recognition, allowances for receivables, inventories, litigation and income taxes. These estimates are based on historical facts and various other factors, which the Company believes to be reasonable at the time the estimates are made. However, as the effects of future events cannot be determined with precision, actual results could differ significantly from management’s estimates. Revenue Recognition The Company applies the provisions of Accounting Standards Codification (“ASC”) 606-10, Revenue from Contracts with Customers (4) allocate the transaction price to the performance obligations in the contract, and (5) recognize revenue when a performance obligation is satisfied. Product revenues consist of sales to original equipment manufacturers, or OEMs, merchant power supply manufacturers and distributors. The Company considers customer purchase orders, which in some cases are governed by master sales agreements, to be the contracts with a customer. In situations where sales are to a distributor, the Company has concluded that its contracts are with the distributor as the Company holds a contract bearing enforceable rights and obligations only with the distributor. As part of its consideration of the contract, the Company evaluates certain factors including the customer’s ability to pay (or credit risk). For each contract, the Company considers the promise to transfer products, each of which is distinct, to be the identified performance obligations. In determining the transaction price the Company evaluates whether the price is subject to refund or adjustment to determine the net consideration to which the Company expects to be entitled. As the Company’s standard payment terms are less than one year, the Company has elected the practical expedient under ASC 606-10-32-18 to not assess whether a contract has a significant financing component. The Company allocates the transaction price to each distinct product based on their relative standalone selling price. The product price as specified on the purchase order is considered the standalone selling price as it is an observable input which depicts the price as if sold to a similar customer in similar circumstances. Revenue is recognized when control of the product is transferred to the customer (i.e., when the Company’s performance obligation is satisfied), which typically occurs at shipment. Further, in determining whether control has transferred, the Company considers if there is a present right to payment and legal title, along with risks and rewards of ownership having transferred to the customer. Frequently, the Company receives orders for products to be delivered over multiple dates that may extend across several reporting periods. The Company invoices for each delivery upon shipment and recognizes revenues for each distinct product delivered, assuming transfer of control has occurred. As scheduled delivery dates are within one year, under the optional exemption provided by ASC 606-10-50-14 revenues allocated to future shipments of partially completed contracts are not disclosed. The Company has also elected the practical expedient under ASC 340-40-25-4 to expense commissions when incurred as the amortization period of the commission asset the Company would have otherwise recognized is less than one year. Sales to international customers that are shipped from the Company’s facility outside of the United States are pursuant to EX Works, or EXW, shipping terms, meaning that control of the product transfers to the customer upon shipment from the Company’s foreign warehouse. Sales to international customers that are shipped from the Company’s facility in California are pursuant to Delivered at Frontier, or DAF, shipping terms. As such, control of the product passes to the customer when the shipment reaches the destination country and revenue is recognized upon the arrival of the product in that country. Shipments to customers in the Americas are pursuant to Free on Board, or FOB, point of origin shipping terms meaning that control is passed to the customer upon shipment. Sales to most distributors are made under terms allowing certain price adjustments and limited rights of return (known as “stock rotation”) of the Company’s products held in their inventory or upon sale to their end customers. Revenue from sales to distributors is recognized upon the transfer of control to the distributor. Frequently, distributors need to sell at a price lower than the standard distribution price in order to win business. At the time the distributor invoices its customer or soon thereafter, the distributor submits a “ship-and-debit” price adjustment claim to the Company to adjust the distributor’s cost from the standard price to the pre-approved lower price. After the Company verifies that the claim was pre-approved, a credit memo is issued to the distributor for the ship-and-debit claim. In determining the transaction price, the Company considers ship-and-debit price adjustments to be variable consideration. Such price adjustments are estimated using the expected value method based on an analysis of actual ship-and-debit claims, at the distributor and product level, over a period of time considered adequate to account for current pricing and business trends. Historically, actual price adjustments for ship-and-debit claims have not materially differed from those estimated and included when determining the transaction price. Stock rotation rights grant the distributor the ability to return certain specified amounts of inventory. Stock rotation adjustments are an additional form of variable consideration and are also estimated using the expected value method based on historical return rates. Historically, distributor stock rotation adjustments have not been material. Sales to certain distributors are made under terms that do not include rights of return or price concessions after the product is shipped to the distributor. Accordingly, upon application of steps one through five above, product revenue is recognized upon shipment and transfer of control. The Company generally provides an assurance warranty that its products will substantially conform to the published specifications for twelve months from the date of shipment. The Company’s liability is limited to either a credit equal to the purchase price or replacement of the defective part. Returns under warranty have historically been immaterial. As such, the Company does not record a specific warranty reserve or consider activities related to such warranty, if any, to be a separate performance obligation. Inventories Inventories (which consist of costs associated with the purchases of wafers from domestic and offshore foundries and of packaged components from offshore assembly manufacturers, as well as internal labor and overhead associated with the testing of both wafers and packaged components). Inventory is recorded at standard cost, which approximates actual cost computed on a first-in, first-out basis, not in excess of net realizable value. The Company routinely evaluates quantities and values of inventories and records a provision for excess and obsolete inventories to reduce its recorded inventory balance to its estimated net realizable value. In order to determine the provision management considers historical usage, forecasted demand, current economic trends and historical write-offs. Income Taxes Income-tax expense is an estimate of current income taxes payable or refundable in the current fiscal year based on reported income before income taxes. Deferred income taxes reflect the effect of temporary differences and carry-forwards that are recognized for financial reporting and income tax purposes. The Company accounts for income taxes under the provisions of ASC 740, Income Taxe The U.S. tax rules require U.S. tax on foreign earnings, known as global intangible low taxed income. Under U.S. GAAP, we are allowed to make an accounting policy choice of either (1) treating taxes due on future U.S. inclusions as a current-period expense when incurred (the “period cost method”) or (2) factoring such amounts into a company’s measurement of its deferred taxes (the “deferred method”). We selected the deferred method of accounting and recorded the associated basis differences anticipated to influence prospective income inclusion calculations. Goodwill and Intangible Assets Goodwill and the Company’s domain name are evaluated in accordance with ASC 350-10, Goodwill and Other Intangible Assets, In accordance with ASC 360-10, Accounting for the Impairment or Disposal of Long-Lived Assets Cash and Cash Equivalents The Company considers cash invested in highly liquid financial instruments with maturities of three months or less at the date of purchase to be cash equivalents. Marketable Securities The Company generally holds securities until maturity; however, they may be sold under certain circumstances including, but not limited to, when necessary for the funding of acquisitions and other strategic investments. As a result, the Company classifies its investment portfolio as available-for-sale. The Company classifies all investments with a maturity date greater than three months at the date of purchase as short-term marketable securities in its consolidated balance sheet. As of December 31, 2023 and 2022, the Company’s marketable securities consisted primarily of commercial paper, corporate bonds, government securities and/or other high-quality commercial securities. Employee Benefits Plan The Company sponsors a 401(k) tax-deferred savings plan for all employees in the United States who meet certain eligibility requirements. Participants may contribute up to the amount allowable as a deduction for federal income tax purposes. The Company is not required to contribute; however, the Company contributes a certain percentage of employee annual salaries on a discretionary basis, not to exceed an established threshold. The Company provided for a contribution of approximately $2.1 million, $2.0 million and $1.9 million in 2023, 2022 and 2021, respectively. Retirement Benefit Obligations (Pension) The Company recognizes the over-funded or under-funded status of a defined benefit pension or post-retirement plan as an asset or liability in the accompanying consolidated balance sheets. Actuarial gains and losses are recorded in accumulated other comprehensive loss, a component of stockholders’ equity, and are amortized as a component of net periodic cost over the remaining estimated service period of participants. Foreign Currency Risk and Foreign Currency Translation As of December 31, 2023, the Company’s primary transactional currency was U.S. dollars; in addition, the Company holds cash in Swiss francs and euros to fund the operations of the Company’s Swiss subsidiary. The foreign exchange rate fluctuation between the U.S. dollar versus the Swiss franc and euro is recorded in other income in the consolidated statements of income. Gains and losses arising from the remeasurement of non-functional currency balances are recorded in other income in the accompanying consolidated statements of income. The Company recognized a loss of $0.4 million in 2023, an immaterial foreign exchange loss in 2022 and a loss of $0.6 million in 2021. The functional currencies of the Company’s other subsidiaries are the local currencies. Accordingly, all assets and liabilities are translated into U.S. dollars at the current exchange rates as of the applicable balance sheet date. Revenues and expenses are translated at the average exchange rate prevailing during the period. Cumulative gains and losses from the translation of the foreign subsidiaries’ financial statements have been included accumulated other comprehensive loss in stockholders’ equity. Warranty The Company generally warrants that its products will substantially conform to the published specifications for 12 months Advertising Advertising costs are expensed as incurred and amounted to $1.3 million, $1.4 million and $1.3 million in 2023, 2022 and 2021, respectively. Research and Development Research and development costs are expensed as incurred. Indemnifications The Company sells products to its distributors under contracts, collectively referred to as Distributor Sales Agreements (“DSA”). Each DSA contains the relevant terms of the contractual arrangement with the distributor, and generally includes certain provisions for indemnifying the distributor against losses, expenses, and liabilities from damages that may be awarded against the distributor in the event the Company’s products are found to infringe upon a patent, copyright, trademark, or other proprietary right of a third party (Customer Indemnification). The DSA generally limits the scope of and remedies for the Customer Indemnification obligations in a variety of industry-standard respects, including, but not limited to, limitations based on time and geography, and a right to replace an infringing product. The Company also, from time to time, has granted a specific indemnification right to individual customers. The Company believes its internal development processes and other policies and practices limit its exposure related to such indemnifications. In addition, the Company requires its employees to sign a proprietary information and inventions agreement, which assigns the rights to its employees’ development work to the Company. To date, the Company has not had to reimburse any of its distributors or customers for any losses related to these indemnifications and no material claims were outstanding as of December 31, 2023. For several reasons, including the lack of prior indemnification claims and the lack of a monetary liability limit for certain infringement cases, the Company cannot determine the maximum amount of potential future payments, if any, related to such indemnifications. Recently Issued Accounting Pronouncements In November 2023, the FASB issued ASU 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures (“ASU 2023-07”), which is intended to improve reportable segment disclosure requirements and expand public entities’ segment disclosures in the annual and interim financial statements. The amendment will require disclosure of significant segment expenses that are regularly provided to the chief operating decision maker and within each reported measure of segment profit or loss, an amount and description of its composition for other segment items and interim disclosures of a reportable segment’s profit or loss and assets. The Company is required to adopt the amendments in fiscal year 2024 for annual and retrospective reporting periods and in the first quarter of fiscal year 2025 for all interim and retrospective reporting periods; with early adoption permitted. The Company is currently evaluating the effect of adopting these amendments on its consolidated financial statements. The Company does not expect the amendment to have a material impact on its consolidated financial statements upon adoption. In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures (“ASU 2023-09”), which modifies the rules on income tax disclosures to require entities to disclose (1) specific categories in the rate reconciliation, (2) the income or loss from continuing operations before income tax expense or benefit (separated between domestic and foreign) and (3) income tax expense or benefit from continuing operations (separated by federal, state and foreign). ASU 2023-09 also requires entities to disclose their income tax payments to international, federal, state and local jurisdictions, among other changes. The guidance is effective for annual periods beginning after December 15, 2024. Early adoption is permitted for annual financial statements that have not yet been issued or made available for issuance. ASU 2023-09 should be applied on a prospective basis, but retrospective application is permitted. The Company is currently evaluating the potential impact of adopting this new guidance on its consolidated financial statements. ​

COMPONENTS OF THE COMPANY'S CON

COMPONENTS OF THE COMPANY'S CONSOLIDATED BALANCE SHEETS	12 Months Ended
	Dec. 31, 2023
COMPONENTS OF THE COMPANY'S CONSOLIDATED BALANCE SHEETS
COMPONENTS OF THE COMPANY'S CONSOLIDATED BALANCE SHEETS	3. COMPONENTS OF THE COMPANY’S CONSOLIDATED BALANCE SHEETS: Accounts Receivable ​ ​ ​ ​ ​ ​ ​ ​ December 31, December 31, (In thousands) ​ 2023 ​ 2022 Accounts receivable trade ​ $ 53,147 ​ $ 78,914 Allowance for ship-and-debit ​ (36,017) ​ (53,184) Allowance for stock rotation and rebate ​ (1,775) ​ (3,759) Allowance for credit losses ​ ​ (681) ​ ​ (1,135) Total ​ $ 14,674 ​ $ 20,836 ​ The Company maintains an allowance for estimated credit losses resulting from the inability of customers to make required payments. This allowance is established using estimates formulated by the Company’s management based upon factors such as the composition of the accounts receivable aging, historical losses, changes in payments patterns, customer creditworthiness, and current economic trends. Receivables determined to be uncollectible are written off and deducted from the allowance. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Allowance for Credit Losses ​ ​ Year Ended ​ ​ December 31, (In thousands) ​ 2023 2022 Beginning balance ​ $ (1,135) ​ $ (445) Provision for credit loss expense ​ (619) ​ (1,859) Receivables written off ​ — ​ 49 Recoveries collected ​ 1,073 ​ 1,120 Ending balance ​ $ (681) ​ $ (1,135) ​ Inventories ​ ​ ​ ​ ​ ​ ​ ​ December 31, December 31, (In thousands) ​ 2023 ​ 2022 Raw materials ​ $ 96,467 ​ $ 75,355 Work-in-process ​ 24,727 ​ 15,440 Finished goods ​ 41,970 ​ 44,625 Total ​ $ 163,164 ​ $ 135,420 ​ Property and Equipment ​ ​ ​ ​ ​ ​ ​ ​ December 31, December 31, (In thousands) ​ 2023 ​ 2022 Land ​ $ 22,178 ​ $ 22,166 Construction-in-progress ​ 17,022 ​ 19,195 Building and improvements ​ 92,049 ​ 89,704 Machinery and equipment ​ 267,941 ​ 253,308 Computer software and hardware and office furniture and fixtures ​ 67,450 ​ 62,574 Total ​ 466,640 ​ 446,947 Less: Accumulated depreciation ​ (302,427) ​ (270,266) Property and equipment, net ​ $ 164,213 ​ $ 176,681 ​ Depreciation expense for property and equipment for fiscal years ended December 31, 2023, 2022 and 2021, was approximately $35.2 million, $34.9 million and $31.5 million, respectively, and was determined using the straight-line method over the following useful lives: ​ ​ ​ ​ ​ ​ Building and improvements ​ ​ 4 - 40 years Machinery and equipment ​ 2 - 8 years Computer software and hardware and office furniture and fixtures ​ 4 - 7 years ​ Total property and equipment (excluding accumulated depreciation) located in the United States at December 31, 2023, 2022 and 2021, was approximately $203.6 million, $190.3 million and $174.6 million, respectively. In 2023, 2022 and 2021, approximately 11%, 12% and 14%, respectively, of total property and equipment (excluding accumulated depreciation) was held in Thailand by one of the Company’s subcontractors. In 2023, 2022 and 2021, approximately 15% of total property and equipment (excluding accumulated depreciation was held by one of the Company’s subcontractors in Malaysia. No other country held 10% or more of total property and equipment in the periods presented. Accumulated Other Comprehensive Loss Changes in accumulated other comprehensive loss for the three years ended December 31, 2023: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Unrealized Gains ​ ​ ​ ​ ​ ​ ​ ​ and Losses on ​ ​ ​ ​ Foreign ​ ​ ​ ​ ​ Available-for-Sale ​ Defined Benefit ​ Currency ​ ​ ​ (In thousands) ​ Securities ​ Pension Items ​ Items ​ Total Balance at January 1, 2021 ​ $ 890 ​ $ (1,641) ​ $ (1,412) ​ $ (2,163) Other comprehensive income (loss) before reclassifications ​ (2,055) ​ 800 ​ (486) ​ (1,741) Amounts reclassified from accumulated other comprehensive loss ​ — ​ 167 (1) — ​ 167 Other comprehensive loss ​ (2,055) ​ 967 ​ (486) ​ (1,574) Balance at December 31, 2021 ​ (1,165) ​ (674) ​ (1,898) ​ (3,737) Other comprehensive income (loss) before reclassifications ​ (4,158) ​ 1,459 ​ (985) ​ (3,684) Amounts reclassified from accumulated other comprehensive loss ​ — ​ 77 (1) — ​ 77 Other comprehensive loss ​ (4,158) ​ 1,536 ​ (985) ​ (3,607) Balance at December 31, 2022 ​ (5,323) ​ 862 ​ (2,883) ​ (7,344) Other comprehensive income (loss) before reclassifications ​ 5,579 ​ 811 ​ (420) ​ 5,970 Amounts reclassified from accumulated other comprehensive loss ​ — ​ (88) (1) — ​ (88) Other comprehensive income ​ 5,579 ​ 723 ​ (420) ​ 5,882 Balance at December 31, 2023 ​ $ 256 ​ $ 1,585 ​ $ (3,303) ​ $ (1,462) (1) This component of accumulated other comprehensive loss is included in the computation of net periodic pension cost for the years ended December 31, 2023, 2022 and 2021.

FAIR VALUE MEASUREMENTS

FAIR VALUE MEASUREMENTS	12 Months Ended
	Dec. 31, 2023
FAIR VALUE MEASUREMENTS
FAIR VALUE MEASUREMENTS	4. FAIR VALUE MEASUREMENTS: ASC 820-10, Fair Value Measurements The Company’s cash equivalents and investment instruments are classified within Level 1 or Level 2 of the fair-value hierarchy because they are valued using quoted market prices, broker or dealer quotations, or alternative pricing sources with reasonable levels of price transparency. The type of instrument valued based on quoted market prices in active markets primarily includes money market securities. This type of instrument is generally classified within Level 1 of the fair-value hierarchy. The types of instruments valued based on other observable inputs (Level 2 of the fair-value hierarchy) include investment-grade corporate bonds and commercial paper. Such types of investments are valued by using a multi-dimensional relational model, the inputs are primarily benchmark yields, reported trades, broker/dealer quotes, issuer spreads, two-sided markets, benchmark securities, bids, offers, and reference data including market research publications. The Company does not hold any instruments that would be classified within Level 3 of the fair-value hierarchy. The fair value hierarchy of the Company’s cash equivalents and marketable securities at December 31, 2023 and 2022, was as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Measurement at ​ ​ December 31, 2023 ​ ​ ​ Quoted Prices in ​ ​ ​ ​ ​ ​ ​ Active Markets for ​ Significant Other ​ ​ ​ ​ ​ Identical Assets ​ Observable Inputs (In thousands) ​ Total Fair Value ​ (Level 1) ​ (Level 2) Commercial paper ​ $ 20,275 ​ $ — ​ $ 20,275 Corporate securities ​ ​ 246,922 ​ ​ — ​ ​ 246,922 Money market funds ​ 491 ​ 491 ​ — Total ​ $ 267,688 ​ $ 491 ​ $ 267,197 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Measurement at ​ ​ December 31, 2022 ​ ​ ​ Quoted Prices in ​ ​ ​ ​ ​ ​ ​ Active Markets for ​ Significant Other ​ ​ ​ ​ ​ Identical Assets ​ Observable Inputs (In thousands) ​ Total Fair Value ​ (Level 1) ​ (Level 2) Commercial paper ​ $ 58,683 ​ $ — ​ $ 58,683 Corporate securities ​ ​ 248,441 ​ ​ — ​ ​ 248,441 Money market funds ​ 363 ​ 363 ​ — Total ​ $ 307,487 ​ $ 363 ​ $ 307,124 ​ The Company did not transfer any investments between level 1 and level 2 of the fair value hierarchy in the years ended December 31, 2023 and 2022.

MARKETABLE SECURITIES

MARKETABLE SECURITIES	12 Months Ended
	Dec. 31, 2023
MARKETABLE SECURITIES
MARKETABLE SECURITIES	5. MARKETABLE SECURITIES: Amortized cost and estimated fair market value of marketable securities classified as available-for-sale (excluding cash equivalents) at December 31, 2023, were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amortized ​ Gross Unrealized ​ Estimated Fair (In thousands) Cost Gains Losses Market Value Investments due in 3 months or less: ​ ​ ​ ​ Corporate securities ​ $ 10,688 ​ $ — ​ $ (42) ​ $ 10,646 Total ​ 10,688 ​ — ​ (42) ​ 10,646 Investments due in 4-12 months: ​ ​ ​ ​ Commercial paper ​ 718 ​ — ​ — ​ 718 Corporate securities ​ ​ 48,680 ​ 15 ​ (347) ​ 48,348 Total ​ 49,398 ​ 15 ​ (347) ​ 49,066 Investments due in 12 months or greater: ​ ​ ​ ​ Corporate securities ​ 187,298 ​ 952 ​ (322) ​ 187,928 Total ​ ​ 187,298 ​ 952 ​ ​ (322) ​ 187,928 Total marketable securities ​ $ 247,384 ​ $ 967 ​ $ (711) ​ $ 247,640 ​ Accrued interest receivable was $2.3 million at December 31, 2023 and was recorded within prepaid expenses and other current assets on the consolidated balance sheet. Amortized cost and estimated fair market value of marketable securities classified as available-for-sale (excluding cash equivalents) at December 31, 2022, were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amortized ​ Gross Unrealized ​ Estimated Fair (In thousands) Cost Gains Losses Market Value Investments due in 3 months or less: ​ ​ ​ ​ Corporate securities ​ $ 21,803 ​ $ — ​ $ (135) ​ $ 21,668 Total ​ 21,803 ​ — ​ (135) ​ 21,668 Investments due in 4-12 months: ​ ​ ​ ​ Corporate securities ​ 173,833 ​ — ​ (4,019) ​ 169,814 Total ​ 173,833 ​ — ​ (4,019) ​ 169,814 Investments due in 12 months or greater: ​ ​ ​ ​ Corporate securities ​ 58,128 ​ 71 ​ (1,240) ​ 56,959 Total ​ 58,128 ​ 71 ​ (1,240) ​ 56,959 Total marketable securities ​ $ 253,764 ​ $ 71 ​ $ (5,394) ​ $ 248,441 ​ Accrued interest receivable was $1.2 million at December 31, 2022 and was recorded within prepaid expenses and other current assets on the consolidated balance sheet. ​ As of December 31, 2023 and 2022 the Company had no marketable securities classified as available-for-sale (excluding cash equivalents) in a continuous unrealized loss position for which an allowance for credit losses was recorded. The following table summarizes marketable securities classified as available-for-sale (excluding cash equivalents) in a continuous unrealized loss position for which an allowance for credit losses was not recorded at December 31, 2023: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Less Than 12 Months ​ 12 Months or Longer ​ Total ​ Estimated Gross Estimated Gross Estimated Gross ​ ​ Fair Market ​ Unrealized ​ Fair Market ​ Unrealized ​ Fair Market ​ Unrealized (In thousands) ​ Value ​ Losses ​ Value ​ Losses ​ Value ​ Losses December 31, 2023 ​ ​ ​ ​ ​ ​ Corporate securities ​ $ 102,729 ​ $ (371) ​ $ 25,401 ​ $ (340) ​ $ 128,130 ​ $ (711) Total marketable securities ​ $ 102,729 ​ $ (371) ​ $ 25,401 ​ $ (340) ​ $ 128,130 ​ $ (711) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Less Than 12 Months ​ 12 Months or Longer ​ Total ​ Estimated Gross Estimated Gross Estimated Gross ​ ​ Fair Market ​ Unrealized ​ Fair Market ​ Unrealized ​ Fair Market ​ Unrealized (In thousands) ​ Value ​ Losses ​ Value ​ Losses ​ Value ​ Losses December 31, 2022 ​ ​ ​ ​ ​ ​ Corporate securities ​ $ 45,047 ​ $ (662) ​ $ 191,443 ​ $ (4,732) ​ $ 236,490 ​ $ (5,394) Total marketable securities ​ $ 45,047 ​ $ (662) ​ $ 191,443 ​ $ (4,732) ​ $ 236,490 ​ $ (5,394) ​ The weighted average interest rate of investments at December 31, 2023 and 2022, was approximately 4.87% and 2.08%, respectively. In the years ended December 31, 2023 and 2022, no unrealized losses on marketable securities were recognized in income.

GOODWILL AND INTANGIBLE ASSETS

GOODWILL AND INTANGIBLE ASSETS	12 Months Ended
	Dec. 31, 2023
GOODWILL AND INTANGIBLE ASSETS
GOODWILL AND INTANGIBLE ASSETS	6. GOODWILL AND INTANGIBLE ASSETS: The carrying amount of goodwill as of December 31, 2023 and 2022 was $91.8 million; there were no changes to goodwill in either of the respective fiscal years. Intangible assets consist primarily of developed technology, acquired licenses, and domain name and are reported net of accumulated amortization. The Company amortizes the cost of all intangible assets over the estimated useful life of the developed technology and technology licenses, which range from two www.power.com primary domain name; the cost to acquire the domain name has been recorded as an intangible asset and will not be amortized as it has an indefinite useful life. Amortization of acquired intangible assets was approximately $2.2 million, $2.4 million and $3.5 million in the years ended December 31, 2023, 2022 and 2021, respectively. The Company does not believe there is any significant residual value associated with the following intangible assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2023 ​ December 31, 2022 ​ ​ ​ Accumulated ​ ​ ​ ​ Accumulated ​ ​ (In thousands) ​ Gross ​ Amortization ​ Net ​ Gross ​ Amortization ​ Net Domain name ​ $ 1,261 ​ $ — ​ $ 1,261 ​ $ 1,261 ​ $ — ​ $ 1,261 Developed technology ​ 37,960 ​ (35,459) ​ 2,501 ​ 37,960 ​ (33,531) ​ 4,429 Technology licenses ​ 1,926 ​ (1,264) ​ 662 ​ 1,926 ​ (1,019) ​ 907 Total intangible assets ​ $ 41,147 ​ $ (36,723) ​ $ 4,424 ​ $ 41,147 ​ $ (34,550) ​ $ 6,597 The estimated future amortization expense related to definite-lived intangible assets at December 31, 2023, is as follows: ​ ​ ​ ​ ​ Estimated ​ ​ Amortization Fiscal Year ​ (In thousands) 2024 ​ $ 1,279 2025 ​ 832 2026 ​ 687 2027 ​ 365 Total ​ $ 3,163 ​

STOCK PLANS AND SHARE BASED COM

STOCK PLANS AND SHARE BASED COMPENSATION	12 Months Ended
	Dec. 31, 2023
STOCK PLANS AND SHARE BASED COMPENSATION
STOCK PLANS AND SHARE BASED COMPENSATION	7. STOCK PLANS AND SHARE BASED COMPENSATION: Stock Plans As of December 31, 2023, the Company had three stock-based compensation plans (the “Plans”) which are described below. 2007 Equity Incentive Plan The 2007 Equity Incentive Plan (“2007 Plan”) was adopted by the board of directors on September 10, 2007, and approved by the stockholders on November 7, 2007, as an amendment and restatement of the 1997 Stock Option Plan (“1997 Plan”). The 2007 Plan provides for the grant of incentive stock options, non-statutory stock options, restricted stock awards, restricted stock unit (“RSU”) awards, stock appreciation rights, performance-based (“PSU”) awards, long-term performance based (“PRSU”) awards and other stock awards to employees, directors and consultants. The 2007 Plan expired in September 2017 with no further grants to be made under this plan; however previous grants under this plan shall remain outstanding until they are exercised, vest, forfeited or expire. 2016 Incentive Award Plan The 2016 Incentive Award Plan (“2016 Plan”) was adopted by the board of directors on March 17, 2016 and approved by the stockholders on May 13, 2016. The 2016 Plan provides for the grant of RSU awards, PSU awards and PRSU awards. No other forms of equity-based awards, including stock options and stock appreciation rights, may be granted under the 2016 Plan. As of December 31, 2023, 3.4 million awards have been issued, net of forfeitures or cancellations, and approximately 3.6 million shares of common stock remain available for future grant under the 2016 Plan. 1997 Employee Stock Purchase Plan Under the 1997 Employee Stock Purchase Plan (Purchase Plan), eligible employees may apply accumulated payroll deductions, which may not exceed 15% of an employee’s compensation, to the purchase of shares of the Company’s common stock at periodic intervals. The purchase price of stock under the Purchase Plan is equal to 85% of the lower of (i) the fair market value of the Company’s common stock on the first day of each offering period, or (ii) the fair market value of the Company’s common stock on the purchase date (as defined in the Purchase Plan). Each offering period consists of one purchase period of approximately six months reserved for issuance, 6.9 million shares had been purchased and 0.6 million shares were reserved for future issuance under the Purchase Plan. Shares Reserved As of December 31, 2023, the Company had approximately 4.4 million shares of common stock reserved for future grant under all stock plans. Stock-Based Compensation The Company applies the provisions of ASC 718-10, Stock Compensation The following table summarizes the stock-based compensation expense recognized in accordance with ASC 718-10 for the years ended December 31, 2023, 2022 and 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, (In thousands) 2023 2022 2021 Cost of revenues ​ $ 1,692 ​ $ 1,132 ​ $ 2,359 Research and development ​ 10,939 ​ 10,428 ​ 12,127 Sales and marketing ​ 6,888 ​ 6,035 ​ 7,630 General and administrative ​ 9,009 ​ 4,769 ​ 15,493 Total stock-based compensation expense ​ $ 28,528 ​ $ 22,364 ​ $ 37,609 ​ The following table summarizes total compensation expense related to unvested awards not yet recognized, net of expected forfeitures, and the weighted average period over which it is expected to be recognized as of December 31, 2023: ​ ​ ​ ​ ​ ​ ​ Unrecognized Compensation Weighted Average ​ ​ Expense for Unvested ​ Remaining Recognition ​ ​ Awards ​ Period ​ ​ (In thousands) ​ (In years) Long-term performance-based awards ​ $ — — Restricted stock units ​ 46,856 2.66 Purchase plan ​ 155 0.08 Total unrecognized compensation expense ​ $ 47,011 ​ Stock-based compensation expense in the year ended December 31, 2023, was approximately $28.5 million, comprising approximately $23.4 million related to restricted stock units, $3.2 million related to performance-based awards and long-term performance-based awards and $1.9 million related to the Company’s Purchase Plan. Stock-based compensation expense in the year ended December 31, 2022, was approximately $22.4 million, comprising approximately $23.2 million related to restricted stock units, $1.9 million related to the Company’s Purchase Plan and a $2.7 million credit related to performance-based awards and long-term performance-based awards. Stock-based compensation expense in the year ended December 31, 2021, was approximately $37.6 million, comprising approximately $19.9 million related to restricted stock units, $15.7 million related to performance-based awards and $2.0 million related to the Company’s Purchase Plan. The fair value of employees’ stock purchase rights under the Purchase Plan was estimated using the Black-Scholes model with the following weighted-average assumptions used during the three years ended December 31, 2023, 2022 and 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ 2023 ​ 2022 ​ 2021 Risk-free interest rates ​ 5.15 % ​ ​ 1.71 % ​ ​ 0.07 % Expected volatility rates ​ 37 % ​ ​ 41 % ​ ​ 41 % Expected dividend yield ​ 0.90 % ​ ​ 0.89 % ​ ​ 0.57 % Expected term of purchase rights (in years) ​ 0.49 ​ ​ 0.50 ​ ​ 0.50 Weighted-average estimated fair value of purchase rights ​ $ 23.75 ​ ​ $ 21.63 ​ ​ $ 23.92 ​ ​ No options were granted or remain outstanding PSU Awards Under the performance-based awards program, the Company grants awards in the performance year in an amount equal to twice the target number of shares to be issued if the maximum performance metrics are met. The number of shares that are released at the end of the performance year can range from zero to 200% of the target number depending on the Company’s performance. The performance metrics of this program are annual targets consisting of a combination of net revenue, non-GAAP operating earnings and strategic goals. As the net revenue, non-GAAP operating income and strategic goals are considered performance conditions, expense associated with these awards, net of estimated forfeitures, is recognized over the service period based on an assessment of the achievement of the performance targets. The fair value of these PSUs is determined using the fair value of the Company’s common stock on the date of the grant, reduced by the discounted present value of dividends expected to be declared before the awards vest. If the performance conditions are not achieved, no compensation cost is recognized and any previously recognized compensation is reversed. A summary of PSU awards outstanding as of December 31, 2023, and activity during the three years then ended, is presented below: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted- ​ ​ ​ ​ ​ ​ ​ ​ ​ Average ​ ​ ​ ​ ​ ​ ​ Weighted-Average ​ Remaining ​ Aggregate ​ ​ Shares ​ Grant Date Fair ​ Contractual Term ​ Intrinsic Value ​ (In thousands) Value Per Share (In years) (In thousands) Outstanding at January 1, 2021 150 ​ $ 46.27 ​ Granted 105 ​ $ 84.48 ​ Vested (150) ​ $ 46.27 ​ Forfeited or canceled (1) ​ $ 85.01 ​ Outstanding at December 31, 2021 104 ​ $ 84.47 ​ Granted 119 ​ $ 79.91 ​ Vested (104) ​ $ 84.48 ​ Forfeited or canceled (85) ​ $ 79.89 ​ Outstanding at December 31, 2022 34 ​ $ 79.94 ​ Granted 131 ​ $ 82.96 ​ Vested (34) ​ $ 79.94 ​ Forfeited or canceled (93) ​ $ 82.96 ​ Outstanding at December 31, 2023 38 ​ $ 82.95 — ​ $ 3,131 Outstanding and expected to vest at December 31, 2023 38 ​ ​ ​ — ​ $ 3,131 ​ In February 2023, it was determined that approximately 34,000 shares subject to the PSUs granted in 2022 vested in aggregate; the shares were released to the Company’s employees and executives in the first quarter of 2023. The grant-date fair value of PSU awards released, which were fully vested, in the years ended December 31, 2023, 2022 and 2021, was approximately $2.7 million, $8.8 million and $6.9 million, respectively. PRSU Awards (Long-term Performance Based) The Company’s PRSU program provides for the issuance of PRSUs which will vest based on the Company’s performance measured against the PRSU program’s established performance targets. PRSUs are granted in an amount equal to twice the target number of shares to be issued if the maximum performance metrics are met. The actual number of shares the recipient receives is determined at the end of a three-year performance period based on results achieved versus the Company’s performance goals, and may range from zero to 200% of the target number. The performance goals for PRSUs granted in fiscal 2021, 2022 and 2023 were based on the Company’s compound annual growth rate (“CAGR”) of revenue as measured against the revenue CAGR of the analog semiconductor industry (“Relative Measure”), in each case over the respective three-year performance period. In addition, the PRSUs granted in 2023 (“2023 PRSUs”) also include a performance goal related to the Company’s revenue growth over the respective three-year performance period as compared to defined targets (“Absolute Measure”) with the actual vesting of the 2023 PRSUs calculated based on higher achievement under the Relative Measure or the Absolute Measure. Expense associated with these awards, net of estimated forfeitures, is recorded throughout the year based on an assessment of the expected achievement of the performance targets. If the performance conditions are not achieved, no compensation cost is recognized and any previously recognized compensation is reversed. Expense associated with these awards, net of estimated forfeitures, is recorded throughout the year based on an assessment of the expected achievement of the performance targets. If the performance conditions are not achieved, no compensation cost is recognized and any previously recognized compensation is reversed. A summary of PRSU awards outstanding as of December 31, 2023, and activity during the three years then ended, is presented below: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-Average ​ Aggregate ​ ​ ​ ​ Weighted-Average ​ Remaining ​ Intrinsic ​ ​ Shares ​ Grant Date Fair ​ Contractual Term ​ Value ​ (In thousands) Value Per Share (In years) (In thousands) Outstanding at January 1, 2021 301 ​ $ 41.90 ​ Granted 103 ​ $ 82.92 ​ Vested (6) ​ $ 29.94 ​ Forfeited or canceled (15) ​ $ 40.05 ​ Outstanding at December 31, 2021 383 ​ $ 53.14 ​ ​ Granted 110 ​ $ 78.96 ​ Vested (135) ​ $ 34.09 ​ Forfeited or canceled (122) ​ $ 49.68 ​ Outstanding at December 31, 2022 236 ​ $ 77.82 ​ Granted 146 ​ $ 80.92 ​ Vested (23) ​ $ 49.68 ​ Forfeited or canceled (103) ​ $ 82.92 ​ Outstanding at December 31, 2023 256 ​ $ 80.08 1.57 ​ $ 20,987 Outstanding and expected to vest at December 31, 2023 — ​ ​ ​ ​ — ​ $ — ​ In February 2023 it was determined that approximately 23,000 shares subject to the PRSUs granted in 2020 vested in aggregate; the shares were released to the Company’s executives in the first quarter of 2023. , RSU Awards RSUs granted to employees typically vest ratably over a four-year period and are converted into shares of the Company’s common stock upon vesting on a one-for-one basis subject to the employee’s continued service to the Company over that period. The fair value of RSUs is determined using the fair value of the Company’s common stock on the date of the grant, reduced by the discounted present value of dividends expected to be declared before the awards vest. Compensation expense is recognized on a straight-line basis over the requisite service period of each grant adjusted for estimated forfeitures. A summary of RSU awards outstanding as of December 31, 2023, and activity during the three years then ended, is presented below: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-Average ​ Aggregate ​ ​ ​ ​ Weighted-Average ​ Remaining ​ Intrinsic ​ ​ Shares ​ Grant Date Fair ​ Contractual Term ​ Value ​ (In thousands) Value Per Share (In years) (In thousands) Outstanding at January 1, 2021 1,518 ​ $ 35.51 ​ Granted 271 ​ $ 83.79 ​ Vested (546) ​ $ 35.03 ​ Forfeited (99) ​ $ 39.85 ​ Outstanding at December 31, 2021 1,144 ​ $ 46.81 ​ Granted 519 ​ $ 76.01 ​ Vested (481) ​ $ 44.70 ​ Forfeited (86) ​ $ 60.02 ​ Outstanding at December 31, 2022 1,096 ​ $ 60.52 ​ Granted 335 ​ $ 80.97 ​ Vested (418) ​ $ 53.08 ​ Forfeited (32) ​ $ 73.29 ​ Outstanding at December 31, 2023 981 ​ $ 70.27 1.48 ​ $ 80,585 Outstanding and expected to vest at December 31, 2023 918 ​ ​ ​ 1.39 ​ $ 75,384 ​ The grant-date fair value of RSUs vested in the years ended December 31, 2023, 2022 and 2021, was approximately $22.2 million, $21.5 million and $19.1 million, respectively.

SIGNIFICANT CUSTOMERS AND GEOGR

SIGNIFICANT CUSTOMERS AND GEOGRAPHIC NET REVENUES	12 Months Ended
	Dec. 31, 2023
SIGNIFICANT CUSTOMERS AND GEOGRAPHIC NET REVENUES
SIGNIFICANT CUSTOMERS AND GEOGRAPHIC NET REVENUES	8. SIGNIFICANT CUSTOMERS AND GEOGRAPHIC NET REVENUES: Customer Concentration The Company’s top ten customers accounted for approximately 80%, 76% and 78% of revenues in 2023, 2022 and 2021, respectively. A significant portion of these revenues are attributable to sales of the Company’s products to distributors of electronic components. These distributors sell the Company’s products to a broad, diverse range of end users, including OEMs and merchant power supply manufacturers. Sales to distributors in 2023, 2022 and 2021 were $307.4 million, $457.7 million and $525.7 million, respectively. Direct sales to OEMs and power-supply manufacturers accounted for the remainder. The following customers represented 10% or more of the Company’s net revenues for the respective years ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, Customer 2023 ​ 2022 ​ 2021 Avnet ​ 27 % ​ 31 % ​ 30 % Honestar Technologies Co., Ltd. ​ 18 % ​ 11 % ​ 16 % Salcomp Group 10 % ​ * ​ ​ * ​ * Total customer revenue was less than 10% of net revenues. No other customers accounted for 10% or more of the Company’s net revenues in the periods presented. Concentration of Credit Risk Financial instruments that potentially subject the Company to concentrations of credit risk consisted principally of cash investments and trade receivables. The Company does not have any off-balance-sheet credit exposure related to its customers. As of December 31, 2023 and 2022, 86% and 87% of accounts receivable were concentrated with the Company’s top ten customers, respectively. The following customers represented 10% or more of accounts receivable: ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, Customer 2023 ​ 2022 Avnet ​ 39 % ​ 42 % Honestar Technologies Co., Ltd. ​ 20 % ​ * ​ Salcomp Group 10 % ​ 13 % Flextronics Group * ​ ​ 11 % * Total customer accounts receivable was less than 10% of accounts receivable. No other customers accounted for 10% or more of the Company’s accounts receivable in the periods presented. Geographic Net Revenues The Company markets its products globally through its sales personnel and a worldwide network of independent sales representatives and distributors. Geographic net revenues based on “bill to” customer locations were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, (In thousands) 2023 2022 2021 United States of America ​ $ 8,676 ​ $ 25,500 ​ $ 17,238 Hong Kong/China ​ 265,936 ​ 356,865 ​ 446,980 India ​ ​ 34,558 ​ ​ 33,159 ​ ​ 25,961 Taiwan ​ 15,774 ​ 19,789 ​ 25,991 Korea ​ 24,956 ​ 52,074 ​ 59,501 Western Europe (excluding Germany) ​ 27,819 ​ 32,429 ​ 35,835 Japan ​ 16,177 ​ 34,924 ​ 25,101 Germany ​ 23,041 ​ 52,876 ​ 32,664 Other ​ 27,601 ​ 43,522 ​ 34,006 Total net revenues ​ $ 444,538 ​ $ 651,138 ​ $ 703,277 ​

COMMON STOCK REPURCHASES AND CA

COMMON STOCK REPURCHASES AND CASH DIVIDENDS	12 Months Ended
	Dec. 31, 2023
COMMON STOCK REPURCHASES AND CASH DIVIDENDS
COMMON STOCK REPURCHASES AND CASH DIVIDENDS	9. COMMON STOCK REPURCHASES AND CASH DIVIDENDS: Common Stock Repurchases From time to time the Company’s board of directors has authorized the use of funds to repurchase shares of the Company’s common stock. In October 2018, the Company’s board of director’s authorized the use of $80.0 million for the repurchase of the Company’s common stock, and in each of April 2021 and October 2021 In 2023, 2022 and 2021 the Company purchased approximately 0.8 million shares, 3.8 million shares and 0.9 million shares, respectively, for approximately $55.3 million, $311.1 million and $73.9 million, respectively. As of December 31, 2023, the Company had $26.0 million available for future stock repurchases. Authorization of future stock repurchase programs is at the discretion of the Company’s board of directors and will depend on the Company’s financial condition, results of operations, capital requirements and business conditions as well as other factors. Common Stock Dividend The following table presents the quarterly dividends declared per share of the Company’s common stock for the periods indicated: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2023 2022 2021 First Quarter ​ $ 0.19 ​ $ 0.18 ​ $ 0.13 Second Quarter ​ $ 0.19 ​ $ 0.18 ​ $ 0.13 Third Quarter ​ $ 0.19 ​ $ 0.18 ​ $ 0.13 Fourth Quarter ​ $ 0.20 ​ $ 0.18 ​ $ 0.15 ​ The Company paid approximately $44.0 million, $41.5 million and $32.6 million in cash dividends during 2023, 2022 and 2021, respectively. In January 2021, 2022 In January 2022, the Company’s board of directors raised the quarterly cash dividend by an additional $0.03 per share with the declaration of four cash dividends of $0.18 per share (in lieu of the $0.15 per share announced in October 2021) to be paid to stockholders of record at the end of each quarter in 2022. In February 2023, 2024

EARNINGS PER SHARE

EARNINGS PER SHARE	12 Months Ended
	Dec. 31, 2023
EARNINGS PER SHARE
EARNINGS PER SHARE	10. EARNINGS PER SHARE: Basic earnings per share are calculated by dividing net income by the weighted-average shares of common stock outstanding during the period. Diluted earnings per share are calculated by dividing net income by the weighted-average shares of common stock and dilutive common equivalent shares outstanding during the period. Dilutive common equivalent shares included in this calculation consist of dilutive shares issuable upon the assumed exercise of outstanding common stock options, the assumed vesting of outstanding restricted stock units, the assumed issuance of awards under the stock purchase plan and contingently issuable performance-based awards, as computed using the treasury stock method. A summary of the earnings per share calculation is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, (In thousands, except per share amounts) 2023 2022 2021 Basic earnings per share: ​ ​ ​ Net income ​ $ 55,735 ​ $ 170,851 ​ $ 164,413 Weighted-average common shares ​ 57,195 ​ 57,801 ​ 60,327 Basic earnings per share ​ $ 0.97 ​ $ 2.96 ​ $ 2.73 Diluted earnings per share: (1) ​ ​ ​ Net income ​ $ 55,735 ​ $ 170,851 ​ $ 164,413 Weighted-average common shares ​ 57,195 ​ 57,801 ​ 60,327 Effect of dilutive awards: ​ ​ ​ Employee stock plans ​ 427 ​ 570 ​ 1,140 Diluted weighted-average common shares ​ 57,622 ​ 58,371 ​ 61,467 Diluted earnings per share ​ $ 0.97 ​ $ 2.93 ​ $ 2.67 (1) The Company includes the shares underlying performance-based awards in the calculation of diluted earnings per share if the performance conditions have been satisfied as of the end of the reporting period and excludes such shares when the necessary conditions have not been met. The Company has included in the 2023, 2022 and 2021 calculations those shares that were contingently issuable upon the satisfaction of the performance conditions as of the end of the respective periods. In the years ended December 31, 2023, 2022 and 2021, no outstanding stock awards were determined to be anti-dilutive and therefore were excluded from the computation of diluted earnings per share.

PROVISION (BENEFIT) FOR INCOME

PROVISION (BENEFIT) FOR INCOME TAXES	12 Months Ended
	Dec. 31, 2023
PROVISION (BENEFIT) FOR INCOME TAXES
PROVISION (BENEFIT) FOR INCOME TAXES	11. PROVISION (BENEFIT) FOR INCOME TAXES: Income Taxes The Company accounts for income taxes under the provisions of ASC 740, Income Taxes U.S. and foreign components of income before income taxes were: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, (In thousands) 2023 2022 2021 U.S. operations ​ $ 2,995 ​ $ 17,250 ​ $ 241 Foreign operations ​ 42,912 ​ 166,176 ​ 175,894 Total income before income taxes ​ $ 45,907 ​ $ 183,426 ​ $ 176,135 ​ The components of the provision (benefit) for income taxes are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, (In thousands) 2023 2022 2021 Current provision (benefit): ​ ​ ​ Federal ​ $ (1,193) ​ $ 19,740 ​ $ 23,648 State ​ 3 ​ 2 ​ 2 Foreign ​ 1,331 ​ 1,079 ​ 1,608 ​ ​ 141 ​ 20,821 ​ 25,258 Deferred provision (benefit): ​ ​ ​ Federal ​ (9,178) ​ (7,962) ​ (11,449) State ​ — ​ — ​ — Foreign ​ (791) ​ (284) ​ (2,087) ​ ​ (9,969) ​ (8,246) ​ (13,536) Total ​ $ (9,828) ​ $ 12,575 ​ $ 11,722 ​ The provision (benefit) for income taxes differs from the amount that would result by applying the applicable federal income tax rate to income before income taxes, as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2023 ​ 2022 ​ 2021 Provision (benefit) computed at Federal statutory rate 21.0 % ​ 21.0 % ​ 21.0 % Business tax credits (12.2) ​ (3.7) ​ (3.6) Stock-based compensation (0.1) ​ (1.6) ​ (0.6) Foreign income taxed at different rate (17.6) ​ (18.5) ​ (23.8) GILTI inclusion 4.1 ​ 8.5 ​ 13.1 Uncertain tax positions (18.6) ​ (0.1) ​ (0.6) Valuation allowance 4.3 ​ 1.3 ​ 1.3 Other (2.3) ​ — ​ (0.1) Total (21.4) % ​ 6.9 % ​ 6.7 % ​ The Company’s effective tax rate is impacted by the geographic distribution of the Company’s world-wide earnings in lower-tax jurisdictions, federal research tax credits and the recognition of excess tax benefits related to share-based payments. In 2023, the rate was further favorably impacted by release of $7.6 million of reserves related to federal uncertain tax positions as the statute of limitations for review of these positions expired. These benefits were partially offset by foreign income subject to U.S. tax, known as global intangible low-taxed income. The Company’s primary jurisdiction where foreign earnings are derived is the Cayman Islands, which is a non-taxing jurisdiction. Income earned in other foreign jurisdictions was not material. The Company has not been granted any incentivized tax rates and does not operate under any tax holidays in any jurisdiction. The components of the net deferred income tax assets (liabilities) were as follows: ​ ​ ​ ​ ​ ​ ​ ​ December 31, (In thousands) ​ 2023 ​ 2022 Deferred tax assets: ​ ​ Capitalized R&D costs ​ $ 30,886 ​ $ 20,666 Other reserves and accruals ​ ​ 861 ​ ​ 2,516 Tax credit carry-forwards ​ 28,223 ​ 26,154 Stock compensation ​ 1,543 ​ 1,559 Capital losses ​ 141 ​ 150 Net operating loss ​ 2,269 ​ 2,217 Other ​ 465 ​ 439 Valuation allowance ​ (31,031) ​ (29,036) ​ ​ 33,357 ​ 24,665 Deferred tax liabilities: ​ ​ Depreciation ​ (5,040) ​ (5,596) ​ ​ (5,040) ​ (5,596) Net deferred tax assets ​ $ 28,317 ​ $ 19,069 ​ In assessing the realizability of deferred tax assets, management considers whether it is more likely than not that some portion or all of the deferred tax assets will not be realized. The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income during the periods in which those temporary differences become deductible. Management considers the scheduled reversal of deferred tax liabilities and projected future taxable income. In the event that the Company determines, based on available evidence and management judgment, that all or part of the net deferred tax assets will not be realized in the future, the Company would record a valuation allowance in the period the determination is made. In addition, the calculation of tax liabilities involves significant judgment in estimating the impact of uncertainties in the application of complex tax laws. Resolution of these uncertainties in a manner inconsistent with the Company’s expectations could have a material impact on its results of operations and financial position. As of December 31, 2023, the Company continues to maintain a valuation allowance primarily as a result of its California, New Jersey and Canada deferred tax assets as the Company believes that it is not more likely than not that the deferred tax assets will be fully realized. As of December 31, 2023, the Company had utilized all of its federal research and development tax credit carryforwards. As of December 31, 2023, the Company had California research and development tax credit carryforwards of approximately $40.7 million (there is no expiration of research and development tax credit carryforwards for the state of California) and California net operating losses of $44.2 million which will begin to expire in 2032 2030 2029 The Tax Act signed into law on December 22, 2017, generally allows companies to repatriate accumulated foreign earnings without incurring additional U.S. federal taxes beginning after December 31, 2017. Local foreign and U.S. states taxes may still be incurred upon repatriation. The Company has not provided for U.S. taxes on its undistributed earnings of foreign subsidiaries. The determination of the future tax consequences of the remittance of these earnings is not practicable. Unrecognized Tax Benefits The Company applies the provisions of ASC 740-10, relating to accounting for uncertain income taxes. Reconciliation of the beginning and ending amount of unrecognized tax benefits: ​ ​ ​ ​ ​ Unrecognized (In thousands) ​ Tax Benefits Unrecognized tax benefits balance at January 1, 2021 ​ $ 21,051 Gross increase for tax positions of current year ​ 2,068 Gross decrease for tax positions of prior years ​ ​ — Statute of limitation release for tax positions of prior years ​ (1,756) Unrecognized tax benefits balance at December 31, 2021 ​ 21,363 Gross increase for tax positions of current year ​ 2,188 Gross decrease for tax positions of prior years ​ ​ — Statute of limitation release for tax positions of prior years ​ (165) Unrecognized tax benefits balance at December 31, 2022 ​ 23,386 Gross increase for tax positions of current year ​ 605 Gross decrease for tax positions of prior years ​ ​ — Statute of limitation release for tax positions of prior years ​ (7,602) Unrecognized tax benefits balance at December 31, 2023 ​ $ 16,389 ​ The Company’s total unrecognized tax benefits as of December 31, 2023, 2022 and 2021, were $16.4 million, $23.4 million and $21.4 million, respectively. An income tax benefit of $4.5 million, net of valuation allowance adjustments, would be recorded if fiscal year 2023 unrecognized tax benefits are recognized. The Company cannot reasonably estimate the amount of the unrecognized tax benefit that could be adjusted in the next twelve months. The Company’s continuing practice is to recognize interest and/or penalties related to income tax matters in income tax expense. The Company had accrued interest and penalties of $0.3 million and $1.2 million as of December 31, 2023 and 2022, respectively, which have been recorded in long-term income taxes payable in the accompanying consolidated balance sheets. As of December 31, 2023, the Company has concluded all U.S. federal income tax matters for the years through 2019. However, due to tax attributes, the IRS may calculate tax adjustments for the 2017 transition tax calculation for positions taken prior to 2017 since it has an extended statute of limitations period totaling six years. The California Franchise Tax Board has started an audit for the Company’s tax years 2018 and 2019, it is currently ongoing.

LEASES AND COMMITMENTS

LEASES AND COMMITMENTS	12 Months Ended
	Dec. 31, 2023
LEASES AND COMMITMENTS
LEASES AND COMMITMENTS	12. LEASES AND COMMITMENTS: Facilities and Leases The Company owns its main executive, administrative, manufacturing and technical offices in San Jose, California. The Company also owns a research and development facility in New Jersey, a design center in Germany and a multipurpose office building in Switzerland. The Company’s leases consist of operating leases for administrative office spaces, research-and-development facilities and sales offices in various countries around the world. The Company determines whether an arrangement is a lease at inception. Some lease agreements contain lease and non-lease components, which are accounted for as a single lease component. Total lease expense was $3.6 million for the year ended December 31, 2023, and $3.3 million in both the years ended December 31, 2022 and 2021; short-term and variable lease expenses were not material during these periods. Balance sheet information related to leases was as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, (In thousands) ​ Balance Sheet Classification ​ 2023 ​ 2022 Right-of-use assets ​ ​ ​ ​ ​ ​ Operating lease assets ​ Other assets ​ $ 10,398 ​ $ 9,153 ​ ​ ​ ​ ​ ​ ​ ​ ​ Lease liabilities ​ ​ ​ Current operating lease liabilities ​ Other accrued liabilities ​ $ 2,626 ​ $ 2,895 Non-current operating lease liabilities ​ Other liabilities ​ 7,354 ​ 5,831 Total ​ ​ ​ $ 9,980 ​ $ 8,726 ​ Initial lease terms are determined at commencement and may include options to extend or terminate the lease when it is reasonably certain the Company will exercise the option. Remaining lease terms range from one some of which include options to extend for up to five years, and some of which include options to terminate within one year. Leases with an initial term of twelve months or less are not recorded on the balance sheet. As the Company’s leases do not provide an implicit rate, the present value of future lease payments is determined using the Company’s incremental borrowing rate based on information available at commencement date. ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, Lease term and discount rate ​ 2023 ​ 2022 Weighted average remaining lease term ​ 3.8 years ​ 4.0 years Weighted average discount rate 6.1 % ​ 4.6 % ​ Supplemental cash flows information related to leases was as follow: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, (In thousands) ​ 2023 ​ 2022 Cash paid for amounts included in the measurement of lease liabilities: ​ ​ ​ ​ ​ Operating cash flows from operating leases ​ $ 3,579 ​ $ 3,245 Right-of-use assets obtained in exchange for new operating lease obligations ​ $ 4,889 ​ $ 1,795 ​ Future minimum lease payments under all non-cancelable lease agreements as of December 31, 2023, are as follows: ​ ​ ​ ​ ​ ​ December 31, (In thousands) ​ 2023 2024 ​ $ 3,168 2025 ​ 3,103 2026 ​ 2,514 2027 ​ 1,359 2028 ​ ​ 852 Thereafter ​ 243 Total future minimum lease payments ​ 11,239 Less imputed interest ​ (1,259) Total ​ $ 9,980 ​ Purchase Obligations At December 31, 2023, the Company had no non-cancelable purchase obligations that were due beyond one year.

LEGAL PROCEEDINGS AND CONTINGEN

LEGAL PROCEEDINGS AND CONTINGENCIES	12 Months Ended
	Dec. 31, 2023
LEGAL PROCEEDINGS AND CONTINGENCIES
LEGAL PROCEEDINGS AND CONTINGENCIES	13. LEGAL PROCEEDINGS AND CONTINGENCIES: From time to time in the ordinary course of business, the Company becomes involved in lawsuits, or customers and distributors may make claims against the Company. In accordance with ASC 450 10, Contingencies, the Company makes a provision for a liability when it is both probable that a liability has been incurred and the amount of the loss can be reasonably estimated. On January 6, 2020, the Company filed a complaint against CogniPower LLC in the United States District Court for the District of Delaware for infringement of two of the Company’s patents and seeking a declaration of non-infringement with respect to patents that CogniPower had charged the Company’s customers with infringing, based on customer use of the Company’s products. In response, CogniPower filed a motion to dismiss the Company’s declaratory judgment claims on the basis that CogniPower had not threatened the Company directly with suit. That motion was granted, so CogniPower’s claims for infringement initially went forward separately in their lawsuit against the Company’s customers in the District of Delaware, but the Company filed a motion to intervene in that lawsuit and received a ruling allowing the Company to intervene in CogniPower’s customer lawsuit on February 1, 2021, and the parties thereafter agreed to dismiss the Company’s separate lawsuit against CogniPower. The remaining case is currently stayed, but the Company recently filed a motion to amend its claims against CogniPower to include three additional patents that are in the same family as the two CogniPower patents that are already in the lawsuit, after CogniPower accused the Company’s customers of infringing those three related patents in a lawsuit in the Eastern District of Texas. A ruling on the Company’s motion is expected in the coming months, and the Company believes it has strong claims and defenses with respect to all of CogniPower’s asserted patents and intends to vigorously defend itself against CogniPower’s claims against the Company’s technology, with appeals to follow if necessary. On October 31, 2022, Waverly Licensing LLC filed a complaint against the Company in the United States District Court for the Western District of Texas. In its complaint, Waverly alleged that the Company was infringing one patent pertaining to charging a battery-operated device. The Company believes it has strong claims and defenses, and intends to vigorously defend itself against Waverly’s claims, with appeals to follow if necessary. Because the Company believed that Waverly’s Texas complaint was improperly filed in the wrong court, the Company filed a motion to dismiss, and on November 30, 2022, the Company filed a complaint against Waverly Licensing LLC and related entities IP Edge LLC, Mavexar LLC, and Array IP LLC in the United States District Court for the District of Delaware seeking a declaration of non-infringement with respect to a patent that Waverly charged the Company with infringing. The Texas court thereafter dismissed Waverly’s Texas complaint. The Company’s Delaware lawsuit is in its earliest stages, but on April 6, 2023, the Delaware defendants filed a motion to dismiss based on a series of covenants not to sue that the Delaware defendants filed with the Court, with further proceedings on the Delaware defendants’ motion expected in the coming months. The Company is unable to predict the outcome of legal proceedings with certainty, and there can be no assurance that the Company will prevail in the above-mentioned unsettled litigations. These litigations, whether or not determined in the Company’s favor or settled, will be costly and will divert the efforts and attention of the Company’s management and technical personnel from normal business operations, potentially causing a material adverse effect on the business, financial condition and operating results. Currently, the Company is not able to estimate a loss or a range of loss for the ongoing litigations disclosed above, however adverse determinations in litigation could result in monetary losses, the loss of proprietary rights, subject the Company to significant liabilities, require the Company to seek licenses from third parties or prevent the Company from licensing the technology, any of which could have a material adverse effect on the Company’s business, financial condition and operating results.

RETIREMENT PLANS

RETIREMENT PLANS	12 Months Ended
	Dec. 31, 2023
RETIREMENT PLANS
RETIREMENT PLANS	14. RETIREMENT PLANS: The Company sponsors a defined benefit pension plan (Pension Plan) for its Swiss subsidiary in accordance with the legal requirements of Switzerland. The plan assets, which provide benefits in the event of an employee’s retirement, death or disability, are held in legally autonomous trustee-administered funds that are subject to Swiss law. Benefits are based on the employee’s age, years of service and salary, and the plan is financed by contributions by both the employee and the Company. The net periodic benefit cost of the Pension Plan was not material to the Company’s financial statements during the years ended December 31, 2023, 2022 and 2021. At December 31, 2023, the projected benefit obligation was $11.4 million, the plan assets were $7.9 million and the net pension liability was $3.5 million. As of December 31, 2022, the projected benefit obligation was $12.1 million, the plan assets were $8.2 million, and the net pension liability was $3.9 million. The Company has recorded the unfunded amount as a liability in its consolidated balance sheet at December 31, 2023 and 2022, under the other liabilities caption. The Company expects to make contributions to the Pension Plan of approximately $0.4 million during 2024. The accumulated unrealized actuarial activity on pension benefits, net of tax, at December 31, 2023, 2022 and 2021 was $1.6 million gain, $0.9 million gain and $0.7 million loss, respectively. These amounts were reflected in Note 3 under the caption accumulated other comprehensive loss. In accordance with the Compensation-Retirement Benefits Topic of ASC 715-20, Defined Benefits Plan

BANK LINE OF CREDIT

BANK LINE OF CREDIT	12 Months Ended
	Dec. 31, 2023
BANK LINE OF CREDIT
BANK LINE OF CREDIT	15. BANK LINE OF CREDIT: On July 27, 2016, the Company entered into a credit agreement with Wells Fargo Bank, National Association (the "Credit Agreement") that provides the Company with a $75.0 million revolving line of credit to use for general corporate purposes with a $20.0 million sub-limit for the issuance of standby and trade letters of credit. The Credit Agreement was amended on April 30, 2018, to extend the termination date from July 26, 2019, to April 30, 2022, with all other terms remaining the same. The Credit Agreement was amended on June 7, 2021, to provide an alternate borrowing rate as a replacement for LIBOR and extend the termination date from April 30, 2022, to June 7, 2026, with all other terms remaining the same. The Credit Agreement was amended with an effective date of June 28, 2023 to include the Secured Overnight Financing Rates (“SOFR”) as interest rate benchmark rates, with all other terms remaining the same. The Company’s ability to borrow under the revolving line of credit is conditioned upon the Company’s compliance with specified covenants, including reporting and financial covenants, primarily a minimum cash requirement and a debt to earnings ratio. The Credit Agreement terminates on June 7, 2026; all advances under the revolving line of credit will become due on such date, or earlier in the event of a default. The Company was compliant with all covenants and had no advances outstanding under the Credit Agreement as of December 31, 2023.

Schedule II - Valuation and Qua

Schedule II - Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2023
Schedule II - Valuation and Qualifying Accounts
Schedule II - Valuation and Qualifying Accounts	Schedule II Valuation and Qualifying Accounts The Company maintains an allowance for the distributors’ ship-and-debit credits relating to the sell-through of the Company’s products. This reserve is established using the Company’s historical ship-and-debit amounts and levels of inventory in the distributor channels. The following is a summary of the activity in the allowance for ship-and-debit credits: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balance at ​ ​ ​ ​ ​ ​ ​ ​ Beginning ​ ​ ​ ​ ​ ​ ​ Balance at End (In thousands) of Period Additions Deductions (1) of Period Allowance for ship-and-debit credits: ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, 2021 ​ $ 26,435 ​ $ 311,443 ​ $ (296,279) ​ $ 41,599 Year ended December 31, 2022 ​ $ 41,599 ​ $ 241,817 ​ $ (230,232) ​ $ 53,184 Year ended December 31, 2023 ​ $ 53,184 ​ $ 202,159 ​ $ (219,326) ​ $ 36,017 (1) Deductions relate to ship-and-debit credits issued which adjust the sales price from the standard distribution price to the pre-approved lower price. Refer to Note 2, Significant Accounting Policies and Recent Accounting Pronouncements , for the Company’s revenue recognition policy, including the Company’s accounting for ship-and-debit claims.

SIGNIFICANT ACCOUNTING POLICI_2

SIGNIFICANT ACCOUNTING POLICIES AND RECENT ACCOUNTING PRONOUNCEMENTS (Policies)	12 Months Ended
	Dec. 31, 2023
SIGNIFICANT ACCOUNTING POLICIES AND RECENT ACCOUNTING PRONOUNCEMENTS
Segment Reporting	Segment Reporting The Company is organized and operates as one reportable segment, the design, development, manufacture and marketing of integrated circuits and related components for use primarily in the high-voltage power conversion markets. The Company’s chief operating decision maker, the Chief Executive Officer, reviews financial information presented on a consolidated basis for purposes of making operating decisions and assessing financial performance.
Principles of Consolidation	Principles of Consolidation The consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries after elimination of all intercompany transactions and balances.
Estimates	Estimates The preparation of financial statements in conformity with U.S. Generally Accepted Accounting Principles (“GAAP”) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. On an ongoing basis, the Company evaluates its estimates, including those related to revenue recognition, allowances for receivables, inventories, litigation and income taxes. These estimates are based on historical facts and various other factors, which the Company believes to be reasonable at the time the estimates are made. However, as the effects of future events cannot be determined with precision, actual results could differ significantly from management’s estimates.
Revenue Recognition	Revenue Recognition The Company applies the provisions of Accounting Standards Codification (“ASC”) 606-10, Revenue from Contracts with Customers (4) allocate the transaction price to the performance obligations in the contract, and (5) recognize revenue when a performance obligation is satisfied. Product revenues consist of sales to original equipment manufacturers, or OEMs, merchant power supply manufacturers and distributors. The Company considers customer purchase orders, which in some cases are governed by master sales agreements, to be the contracts with a customer. In situations where sales are to a distributor, the Company has concluded that its contracts are with the distributor as the Company holds a contract bearing enforceable rights and obligations only with the distributor. As part of its consideration of the contract, the Company evaluates certain factors including the customer’s ability to pay (or credit risk). For each contract, the Company considers the promise to transfer products, each of which is distinct, to be the identified performance obligations. In determining the transaction price the Company evaluates whether the price is subject to refund or adjustment to determine the net consideration to which the Company expects to be entitled. As the Company’s standard payment terms are less than one year, the Company has elected the practical expedient under ASC 606-10-32-18 to not assess whether a contract has a significant financing component. The Company allocates the transaction price to each distinct product based on their relative standalone selling price. The product price as specified on the purchase order is considered the standalone selling price as it is an observable input which depicts the price as if sold to a similar customer in similar circumstances. Revenue is recognized when control of the product is transferred to the customer (i.e., when the Company’s performance obligation is satisfied), which typically occurs at shipment. Further, in determining whether control has transferred, the Company considers if there is a present right to payment and legal title, along with risks and rewards of ownership having transferred to the customer. Frequently, the Company receives orders for products to be delivered over multiple dates that may extend across several reporting periods. The Company invoices for each delivery upon shipment and recognizes revenues for each distinct product delivered, assuming transfer of control has occurred. As scheduled delivery dates are within one year, under the optional exemption provided by ASC 606-10-50-14 revenues allocated to future shipments of partially completed contracts are not disclosed. The Company has also elected the practical expedient under ASC 340-40-25-4 to expense commissions when incurred as the amortization period of the commission asset the Company would have otherwise recognized is less than one year. Sales to international customers that are shipped from the Company’s facility outside of the United States are pursuant to EX Works, or EXW, shipping terms, meaning that control of the product transfers to the customer upon shipment from the Company’s foreign warehouse. Sales to international customers that are shipped from the Company’s facility in California are pursuant to Delivered at Frontier, or DAF, shipping terms. As such, control of the product passes to the customer when the shipment reaches the destination country and revenue is recognized upon the arrival of the product in that country. Shipments to customers in the Americas are pursuant to Free on Board, or FOB, point of origin shipping terms meaning that control is passed to the customer upon shipment. Sales to most distributors are made under terms allowing certain price adjustments and limited rights of return (known as “stock rotation”) of the Company’s products held in their inventory or upon sale to their end customers. Revenue from sales to distributors is recognized upon the transfer of control to the distributor. Frequently, distributors need to sell at a price lower than the standard distribution price in order to win business. At the time the distributor invoices its customer or soon thereafter, the distributor submits a “ship-and-debit” price adjustment claim to the Company to adjust the distributor’s cost from the standard price to the pre-approved lower price. After the Company verifies that the claim was pre-approved, a credit memo is issued to the distributor for the ship-and-debit claim. In determining the transaction price, the Company considers ship-and-debit price adjustments to be variable consideration. Such price adjustments are estimated using the expected value method based on an analysis of actual ship-and-debit claims, at the distributor and product level, over a period of time considered adequate to account for current pricing and business trends. Historically, actual price adjustments for ship-and-debit claims have not materially differed from those estimated and included when determining the transaction price. Stock rotation rights grant the distributor the ability to return certain specified amounts of inventory. Stock rotation adjustments are an additional form of variable consideration and are also estimated using the expected value method based on historical return rates. Historically, distributor stock rotation adjustments have not been material. Sales to certain distributors are made under terms that do not include rights of return or price concessions after the product is shipped to the distributor. Accordingly, upon application of steps one through five above, product revenue is recognized upon shipment and transfer of control. The Company generally provides an assurance warranty that its products will substantially conform to the published specifications for twelve months from the date of shipment. The Company’s liability is limited to either a credit equal to the purchase price or replacement of the defective part. Returns under warranty have historically been immaterial. As such, the Company does not record a specific warranty reserve or consider activities related to such warranty, if any, to be a separate performance obligation.
Inventories	Inventories Inventories (which consist of costs associated with the purchases of wafers from domestic and offshore foundries and of packaged components from offshore assembly manufacturers, as well as internal labor and overhead associated with the testing of both wafers and packaged components). Inventory is recorded at standard cost, which approximates actual cost computed on a first-in, first-out basis, not in excess of net realizable value. The Company routinely evaluates quantities and values of inventories and records a provision for excess and obsolete inventories to reduce its recorded inventory balance to its estimated net realizable value. In order to determine the provision management considers historical usage, forecasted demand, current economic trends and historical write-offs.
Income Taxes	Income Taxes Income-tax expense is an estimate of current income taxes payable or refundable in the current fiscal year based on reported income before income taxes. Deferred income taxes reflect the effect of temporary differences and carry-forwards that are recognized for financial reporting and income tax purposes. The Company accounts for income taxes under the provisions of ASC 740, Income Taxe The U.S. tax rules require U.S. tax on foreign earnings, known as global intangible low taxed income. Under U.S. GAAP, we are allowed to make an accounting policy choice of either (1) treating taxes due on future U.S. inclusions as a current-period expense when incurred (the “period cost method”) or (2) factoring such amounts into a company’s measurement of its deferred taxes (the “deferred method”). We selected the deferred method of accounting and recorded the associated basis differences anticipated to influence prospective income inclusion calculations.
Goodwill and Intangible Assets	Goodwill and Intangible Assets Goodwill and the Company’s domain name are evaluated in accordance with ASC 350-10, Goodwill and Other Intangible Assets, In accordance with ASC 360-10, Accounting for the Impairment or Disposal of Long-Lived Assets
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers cash invested in highly liquid financial instruments with maturities of three months or less at the date of purchase to be cash equivalents.
Marketable Securities	Marketable Securities The Company generally holds securities until maturity; however, they may be sold under certain circumstances including, but not limited to, when necessary for the funding of acquisitions and other strategic investments. As a result, the Company classifies its investment portfolio as available-for-sale. The Company classifies all investments with a maturity date greater than three months at the date of purchase as short-term marketable securities in its consolidated balance sheet. As of December 31, 2023 and 2022, the Company’s marketable securities consisted primarily of commercial paper, corporate bonds, government securities and/or other high-quality commercial securities.
Employee Benefits Plan	Employee Benefits Plan The Company sponsors a 401(k) tax-deferred savings plan for all employees in the United States who meet certain eligibility requirements. Participants may contribute up to the amount allowable as a deduction for federal income tax purposes. The Company is not required to contribute; however, the Company contributes a certain percentage of employee annual salaries on a discretionary basis, not to exceed an established threshold. The Company provided for a contribution of approximately $2.1 million, $2.0 million and $1.9 million in 2023, 2022 and 2021, respectively.
Retirement Benefit Obligations (Pension)	Retirement Benefit Obligations (Pension) The Company recognizes the over-funded or under-funded status of a defined benefit pension or post-retirement plan as an asset or liability in the accompanying consolidated balance sheets. Actuarial gains and losses are recorded in accumulated other comprehensive loss, a component of stockholders’ equity, and are amortized as a component of net periodic cost over the remaining estimated service period of participants.
Foreign Currency Risk and Foreign Currency Translation	Foreign Currency Risk and Foreign Currency Translation As of December 31, 2023, the Company’s primary transactional currency was U.S. dollars; in addition, the Company holds cash in Swiss francs and euros to fund the operations of the Company’s Swiss subsidiary. The foreign exchange rate fluctuation between the U.S. dollar versus the Swiss franc and euro is recorded in other income in the consolidated statements of income. Gains and losses arising from the remeasurement of non-functional currency balances are recorded in other income in the accompanying consolidated statements of income. The Company recognized a loss of $0.4 million in 2023, an immaterial foreign exchange loss in 2022 and a loss of $0.6 million in 2021. The functional currencies of the Company’s other subsidiaries are the local currencies. Accordingly, all assets and liabilities are translated into U.S. dollars at the current exchange rates as of the applicable balance sheet date. Revenues and expenses are translated at the average exchange rate prevailing during the period. Cumulative gains and losses from the translation of the foreign subsidiaries’ financial statements have been included accumulated other comprehensive loss in stockholders’ equity.
Warranty	Warranty The Company generally warrants that its products will substantially conform to the published specifications for 12 months
Advertising	Advertising Advertising costs are expensed as incurred and amounted to $1.3 million, $1.4 million and $1.3 million in 2023, 2022 and 2021, respectively.
Research and Development	Research and Development Research and development costs are expensed as incurred.
Indemnifications	Indemnifications The Company sells products to its distributors under contracts, collectively referred to as Distributor Sales Agreements (“DSA”). Each DSA contains the relevant terms of the contractual arrangement with the distributor, and generally includes certain provisions for indemnifying the distributor against losses, expenses, and liabilities from damages that may be awarded against the distributor in the event the Company’s products are found to infringe upon a patent, copyright, trademark, or other proprietary right of a third party (Customer Indemnification). The DSA generally limits the scope of and remedies for the Customer Indemnification obligations in a variety of industry-standard respects, including, but not limited to, limitations based on time and geography, and a right to replace an infringing product. The Company also, from time to time, has granted a specific indemnification right to individual customers. The Company believes its internal development processes and other policies and practices limit its exposure related to such indemnifications. In addition, the Company requires its employees to sign a proprietary information and inventions agreement, which assigns the rights to its employees’ development work to the Company. To date, the Company has not had to reimburse any of its distributors or customers for any losses related to these indemnifications and no material claims were outstanding as of December 31, 2023. For several reasons, including the lack of prior indemnification claims and the lack of a monetary liability limit for certain infringement cases, the Company cannot determine the maximum amount of potential future payments, if any, related to such indemnifications.
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements In November 2023, the FASB issued ASU 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures (“ASU 2023-07”), which is intended to improve reportable segment disclosure requirements and expand public entities’ segment disclosures in the annual and interim financial statements. The amendment will require disclosure of significant segment expenses that are regularly provided to the chief operating decision maker and within each reported measure of segment profit or loss, an amount and description of its composition for other segment items and interim disclosures of a reportable segment’s profit or loss and assets. The Company is required to adopt the amendments in fiscal year 2024 for annual and retrospective reporting periods and in the first quarter of fiscal year 2025 for all interim and retrospective reporting periods; with early adoption permitted. The Company is currently evaluating the effect of adopting these amendments on its consolidated financial statements. The Company does not expect the amendment to have a material impact on its consolidated financial statements upon adoption. In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures (“ASU 2023-09”), which modifies the rules on income tax disclosures to require entities to disclose (1) specific categories in the rate reconciliation, (2) the income or loss from continuing operations before income tax expense or benefit (separated between domestic and foreign) and (3) income tax expense or benefit from continuing operations (separated by federal, state and foreign). ASU 2023-09 also requires entities to disclose their income tax payments to international, federal, state and local jurisdictions, among other changes. The guidance is effective for annual periods beginning after December 15, 2024. Early adoption is permitted for annual financial statements that have not yet been issued or made available for issuance. ASU 2023-09 should be applied on a prospective basis, but retrospective application is permitted. The Company is currently evaluating the potential impact of adopting this new guidance on its consolidated financial statements. ​

FAIR VALUE MEASUREMENTS (Polici

FAIR VALUE MEASUREMENTS (Policies)	12 Months Ended
	Dec. 31, 2023
FAIR VALUE MEASUREMENTS
Fair Value of Financial Instruments	The Company’s cash equivalents and investment instruments are classified within Level 1 or Level 2 of the fair-value hierarchy because they are valued using quoted market prices, broker or dealer quotations, or alternative pricing sources with reasonable levels of price transparency. The type of instrument valued based on quoted market prices in active markets primarily includes money market securities. This type of instrument is generally classified within Level 1 of the fair-value hierarchy. The types of instruments valued based on other observable inputs (Level 2 of the fair-value hierarchy) include investment-grade corporate bonds and commercial paper. Such types of investments are valued by using a multi-dimensional relational model, the inputs are primarily benchmark yields, reported trades, broker/dealer quotes, issuer spreads, two-sided markets, benchmark securities, bids, offers, and reference data including market research publications.

STOCK PLANS AND SHARE BASED C_2

STOCK PLANS AND SHARE BASED COMPENSATION (Policies)	12 Months Ended
	Dec. 31, 2023
STOCK PLANS AND SHARE BASED COMPENSATION
Stock-Based Compensation	Stock-Based Compensation The Company applies the provisions of ASC 718-10, Stock Compensation

COMPONENTS OF THE COMPANY'S C_2

COMPONENTS OF THE COMPANY'S CONSOLIDATED BALANCE SHEETS (Tables)	12 Months Ended
	Dec. 31, 2023
COMPONENTS OF THE COMPANY'S CONSOLIDATED BALANCE SHEETS
Schedule of Accounts Receivable	Accounts Receivable ​ ​ ​ ​ ​ ​ ​ ​ December 31, December 31, (In thousands) ​ 2023 ​ 2022 Accounts receivable trade ​ $ 53,147 ​ $ 78,914 Allowance for ship-and-debit ​ (36,017) ​ (53,184) Allowance for stock rotation and rebate ​ (1,775) ​ (3,759) Allowance for credit losses ​ ​ (681) ​ ​ (1,135) Total ​ $ 14,674 ​ $ 20,836
Schedule of Allowance for Credit Losses	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Allowance for Credit Losses ​ ​ Year Ended ​ ​ December 31, (In thousands) ​ 2023 2022 Beginning balance ​ $ (1,135) ​ $ (445) Provision for credit loss expense ​ (619) ​ (1,859) Receivables written off ​ — ​ 49 Recoveries collected ​ 1,073 ​ 1,120 Ending balance ​ $ (681) ​ $ (1,135)
Schedule of Inventories	Inventories ​ ​ ​ ​ ​ ​ ​ ​ December 31, December 31, (In thousands) ​ 2023 ​ 2022 Raw materials ​ $ 96,467 ​ $ 75,355 Work-in-process ​ 24,727 ​ 15,440 Finished goods ​ 41,970 ​ 44,625 Total ​ $ 163,164 ​ $ 135,420
Property and Equipment	Property and Equipment ​ ​ ​ ​ ​ ​ ​ ​ December 31, December 31, (In thousands) ​ 2023 ​ 2022 Land ​ $ 22,178 ​ $ 22,166 Construction-in-progress ​ 17,022 ​ 19,195 Building and improvements ​ 92,049 ​ 89,704 Machinery and equipment ​ 267,941 ​ 253,308 Computer software and hardware and office furniture and fixtures ​ 67,450 ​ 62,574 Total ​ 466,640 ​ 446,947 Less: Accumulated depreciation ​ (302,427) ​ (270,266) Property and equipment, net ​ $ 164,213 ​ $ 176,681
Property and Equipment Useful Lives	​ ​ ​ ​ ​ ​ Building and improvements ​ ​ 4 - 40 years Machinery and equipment ​ 2 - 8 years Computer software and hardware and office furniture and fixtures ​ 4 - 7 years
Schedule of Accumulated Other Comprehensive Loss	Changes in accumulated other comprehensive loss for the three years ended December 31, 2023: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Unrealized Gains ​ ​ ​ ​ ​ ​ ​ ​ and Losses on ​ ​ ​ ​ Foreign ​ ​ ​ ​ ​ Available-for-Sale ​ Defined Benefit ​ Currency ​ ​ ​ (In thousands) ​ Securities ​ Pension Items ​ Items ​ Total Balance at January 1, 2021 ​ $ 890 ​ $ (1,641) ​ $ (1,412) ​ $ (2,163) Other comprehensive income (loss) before reclassifications ​ (2,055) ​ 800 ​ (486) ​ (1,741) Amounts reclassified from accumulated other comprehensive loss ​ — ​ 167 (1) — ​ 167 Other comprehensive loss ​ (2,055) ​ 967 ​ (486) ​ (1,574) Balance at December 31, 2021 ​ (1,165) ​ (674) ​ (1,898) ​ (3,737) Other comprehensive income (loss) before reclassifications ​ (4,158) ​ 1,459 ​ (985) ​ (3,684) Amounts reclassified from accumulated other comprehensive loss ​ — ​ 77 (1) — ​ 77 Other comprehensive loss ​ (4,158) ​ 1,536 ​ (985) ​ (3,607) Balance at December 31, 2022 ​ (5,323) ​ 862 ​ (2,883) ​ (7,344) Other comprehensive income (loss) before reclassifications ​ 5,579 ​ 811 ​ (420) ​ 5,970 Amounts reclassified from accumulated other comprehensive loss ​ — ​ (88) (1) — ​ (88) Other comprehensive income ​ 5,579 ​ 723 ​ (420) ​ 5,882 Balance at December 31, 2023 ​ $ 256 ​ $ 1,585 ​ $ (3,303) ​ $ (1,462) (1) This component of accumulated other comprehensive loss is included in the computation of net periodic pension cost for the years ended December 31, 2023, 2022 and 2021.

FAIR VALUE MEASUREMENTS (Tables

FAIR VALUE MEASUREMENTS (Tables)	12 Months Ended
	Dec. 31, 2023
FAIR VALUE MEASUREMENTS
Fair Value of Cash Equivalents and Marketable Securities	The fair value hierarchy of the Company’s cash equivalents and marketable securities at December 31, 2023 and 2022, was as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Measurement at ​ ​ December 31, 2023 ​ ​ ​ Quoted Prices in ​ ​ ​ ​ ​ ​ ​ Active Markets for ​ Significant Other ​ ​ ​ ​ ​ Identical Assets ​ Observable Inputs (In thousands) ​ Total Fair Value ​ (Level 1) ​ (Level 2) Commercial paper ​ $ 20,275 ​ $ — ​ $ 20,275 Corporate securities ​ ​ 246,922 ​ ​ — ​ ​ 246,922 Money market funds ​ 491 ​ 491 ​ — Total ​ $ 267,688 ​ $ 491 ​ $ 267,197 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Measurement at ​ ​ December 31, 2022 ​ ​ ​ Quoted Prices in ​ ​ ​ ​ ​ ​ ​ Active Markets for ​ Significant Other ​ ​ ​ ​ ​ Identical Assets ​ Observable Inputs (In thousands) ​ Total Fair Value ​ (Level 1) ​ (Level 2) Commercial paper ​ $ 58,683 ​ $ — ​ $ 58,683 Corporate securities ​ ​ 248,441 ​ ​ — ​ ​ 248,441 Money market funds ​ 363 ​ 363 ​ — Total ​ $ 307,487 ​ $ 363 ​ $ 307,124

MARKETABLE SECURITIES (Tables)

MARKETABLE SECURITIES (Tables)	12 Months Ended
	Dec. 31, 2023
MARKETABLE SECURITIES
Schedule of Available-for-sale Securities	Amortized cost and estimated fair market value of marketable securities classified as available-for-sale (excluding cash equivalents) at December 31, 2023, were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amortized ​ Gross Unrealized ​ Estimated Fair (In thousands) Cost Gains Losses Market Value Investments due in 3 months or less: ​ ​ ​ ​ Corporate securities ​ $ 10,688 ​ $ — ​ $ (42) ​ $ 10,646 Total ​ 10,688 ​ — ​ (42) ​ 10,646 Investments due in 4-12 months: ​ ​ ​ ​ Commercial paper ​ 718 ​ — ​ — ​ 718 Corporate securities ​ ​ 48,680 ​ 15 ​ (347) ​ 48,348 Total ​ 49,398 ​ 15 ​ (347) ​ 49,066 Investments due in 12 months or greater: ​ ​ ​ ​ Corporate securities ​ 187,298 ​ 952 ​ (322) ​ 187,928 Total ​ ​ 187,298 ​ 952 ​ ​ (322) ​ 187,928 Total marketable securities ​ $ 247,384 ​ $ 967 ​ $ (711) ​ $ 247,640 ​ Amortized cost and estimated fair market value of marketable securities classified as available-for-sale (excluding cash equivalents) at December 31, 2022, were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amortized ​ Gross Unrealized ​ Estimated Fair (In thousands) Cost Gains Losses Market Value Investments due in 3 months or less: ​ ​ ​ ​ Corporate securities ​ $ 21,803 ​ $ — ​ $ (135) ​ $ 21,668 Total ​ 21,803 ​ — ​ (135) ​ 21,668 Investments due in 4-12 months: ​ ​ ​ ​ Corporate securities ​ 173,833 ​ — ​ (4,019) ​ 169,814 Total ​ 173,833 ​ — ​ (4,019) ​ 169,814 Investments due in 12 months or greater: ​ ​ ​ ​ Corporate securities ​ 58,128 ​ 71 ​ (1,240) ​ 56,959 Total ​ 58,128 ​ 71 ​ (1,240) ​ 56,959 Total marketable securities ​ $ 253,764 ​ $ 71 ​ $ (5,394) ​ $ 248,441 ​
Schedule of Available-for-sale Securities in an Unrealized Loss Position	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Less Than 12 Months ​ 12 Months or Longer ​ Total ​ Estimated Gross Estimated Gross Estimated Gross ​ ​ Fair Market ​ Unrealized ​ Fair Market ​ Unrealized ​ Fair Market ​ Unrealized (In thousands) ​ Value ​ Losses ​ Value ​ Losses ​ Value ​ Losses December 31, 2023 ​ ​ ​ ​ ​ ​ Corporate securities ​ $ 102,729 ​ $ (371) ​ $ 25,401 ​ $ (340) ​ $ 128,130 ​ $ (711) Total marketable securities ​ $ 102,729 ​ $ (371) ​ $ 25,401 ​ $ (340) ​ $ 128,130 ​ $ (711) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Less Than 12 Months ​ 12 Months or Longer ​ Total ​ Estimated Gross Estimated Gross Estimated Gross ​ ​ Fair Market ​ Unrealized ​ Fair Market ​ Unrealized ​ Fair Market ​ Unrealized (In thousands) ​ Value ​ Losses ​ Value ​ Losses ​ Value ​ Losses December 31, 2022 ​ ​ ​ ​ ​ ​ Corporate securities ​ $ 45,047 ​ $ (662) ​ $ 191,443 ​ $ (4,732) ​ $ 236,490 ​ $ (5,394) Total marketable securities ​ $ 45,047 ​ $ (662) ​ $ 191,443 ​ $ (4,732) ​ $ 236,490 ​ $ (5,394)

GOODWILL AND INTANGIBLE ASSETS

GOODWILL AND INTANGIBLE ASSETS (Tables)	12 Months Ended
	Dec. 31, 2023
GOODWILL AND INTANGIBLE ASSETS
Schedule Of Intangible Assets	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2023 ​ December 31, 2022 ​ ​ ​ Accumulated ​ ​ ​ ​ Accumulated ​ ​ (In thousands) ​ Gross ​ Amortization ​ Net ​ Gross ​ Amortization ​ Net Domain name ​ $ 1,261 ​ $ — ​ $ 1,261 ​ $ 1,261 ​ $ — ​ $ 1,261 Developed technology ​ 37,960 ​ (35,459) ​ 2,501 ​ 37,960 ​ (33,531) ​ 4,429 Technology licenses ​ 1,926 ​ (1,264) ​ 662 ​ 1,926 ​ (1,019) ​ 907 Total intangible assets ​ $ 41,147 ​ $ (36,723) ​ $ 4,424 ​ $ 41,147 ​ $ (34,550) ​ $ 6,597
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense	The estimated future amortization expense related to definite-lived intangible assets at December 31, 2023, is as follows: ​ ​ ​ ​ ​ Estimated ​ ​ Amortization Fiscal Year ​ (In thousands) 2024 ​ $ 1,279 2025 ​ 832 2026 ​ 687 2027 ​ 365 Total ​ $ 3,163 ​

STOCK PLANS AND SHARE BASED C_3

STOCK PLANS AND SHARE BASED COMPENSATION (Tables)	12 Months Ended
	Dec. 31, 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of Stock-based Compensation Expense	The following table summarizes the stock-based compensation expense recognized in accordance with ASC 718-10 for the years ended December 31, 2023, 2022 and 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, (In thousands) 2023 2022 2021 Cost of revenues ​ $ 1,692 ​ $ 1,132 ​ $ 2,359 Research and development ​ 10,939 ​ 10,428 ​ 12,127 Sales and marketing ​ 6,888 ​ 6,035 ​ 7,630 General and administrative ​ 9,009 ​ 4,769 ​ 15,493 Total stock-based compensation expense ​ $ 28,528 ​ $ 22,364 ​ $ 37,609
Share-based Payment Arrangement, Nonvested Award, Cost	The following table summarizes total compensation expense related to unvested awards not yet recognized, net of expected forfeitures, and the weighted average period over which it is expected to be recognized as of December 31, 2023: ​ ​ ​ ​ ​ ​ ​ Unrecognized Compensation Weighted Average ​ ​ Expense for Unvested ​ Remaining Recognition ​ ​ Awards ​ Period ​ ​ (In thousands) ​ (In years) Long-term performance-based awards ​ $ — — Restricted stock units ​ 46,856 2.66 Purchase plan ​ 155 0.08 Total unrecognized compensation expense ​ $ 47,011
Fair value assumptions for employees' stock purchase rights under the Purchase Plan	The fair value of employees’ stock purchase rights under the Purchase Plan was estimated using the Black-Scholes model with the following weighted-average assumptions used during the three years ended December 31, 2023, 2022 and 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ 2023 ​ 2022 ​ 2021 Risk-free interest rates ​ 5.15 % ​ ​ 1.71 % ​ ​ 0.07 % Expected volatility rates ​ 37 % ​ ​ 41 % ​ ​ 41 % Expected dividend yield ​ 0.90 % ​ ​ 0.89 % ​ ​ 0.57 % Expected term of purchase rights (in years) ​ 0.49 ​ ​ 0.50 ​ ​ 0.50 Weighted-average estimated fair value of purchase rights ​ $ 23.75 ​ ​ $ 21.63 ​ ​ $ 23.92 ​
Schedule of Share-based Compensation, Restricted Stock Units Award Activity	A summary of RSU awards outstanding as of December 31, 2023, and activity during the three years then ended, is presented below: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-Average ​ Aggregate ​ ​ ​ ​ Weighted-Average ​ Remaining ​ Intrinsic ​ ​ Shares ​ Grant Date Fair ​ Contractual Term ​ Value ​ (In thousands) Value Per Share (In years) (In thousands) Outstanding at January 1, 2021 1,518 ​ $ 35.51 ​ Granted 271 ​ $ 83.79 ​ Vested (546) ​ $ 35.03 ​ Forfeited (99) ​ $ 39.85 ​ Outstanding at December 31, 2021 1,144 ​ $ 46.81 ​ Granted 519 ​ $ 76.01 ​ Vested (481) ​ $ 44.70 ​ Forfeited (86) ​ $ 60.02 ​ Outstanding at December 31, 2022 1,096 ​ $ 60.52 ​ Granted 335 ​ $ 80.97 ​ Vested (418) ​ $ 53.08 ​ Forfeited (32) ​ $ 73.29 ​ Outstanding at December 31, 2023 981 ​ $ 70.27 1.48 ​ $ 80,585 Outstanding and expected to vest at December 31, 2023 918 ​ ​ ​ 1.39 ​ $ 75,384
Performance Based Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Summary of performance-based awards outstanding	A summary of PSU awards outstanding as of December 31, 2023, and activity during the three years then ended, is presented below: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted- ​ ​ ​ ​ ​ ​ ​ ​ ​ Average ​ ​ ​ ​ ​ ​ ​ Weighted-Average ​ Remaining ​ Aggregate ​ ​ Shares ​ Grant Date Fair ​ Contractual Term ​ Intrinsic Value ​ (In thousands) Value Per Share (In years) (In thousands) Outstanding at January 1, 2021 150 ​ $ 46.27 ​ Granted 105 ​ $ 84.48 ​ Vested (150) ​ $ 46.27 ​ Forfeited or canceled (1) ​ $ 85.01 ​ Outstanding at December 31, 2021 104 ​ $ 84.47 ​ Granted 119 ​ $ 79.91 ​ Vested (104) ​ $ 84.48 ​ Forfeited or canceled (85) ​ $ 79.89 ​ Outstanding at December 31, 2022 34 ​ $ 79.94 ​ Granted 131 ​ $ 82.96 ​ Vested (34) ​ $ 79.94 ​ Forfeited or canceled (93) ​ $ 82.96 ​ Outstanding at December 31, 2023 38 ​ $ 82.95 — ​ $ 3,131 Outstanding and expected to vest at December 31, 2023 38 ​ ​ ​ — ​ $ 3,131
Long-Term Performance-Based Awards (PRSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Summary of performance-based awards outstanding	A summary of PRSU awards outstanding as of December 31, 2023, and activity during the three years then ended, is presented below: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-Average ​ Aggregate ​ ​ ​ ​ Weighted-Average ​ Remaining ​ Intrinsic ​ ​ Shares ​ Grant Date Fair ​ Contractual Term ​ Value ​ (In thousands) Value Per Share (In years) (In thousands) Outstanding at January 1, 2021 301 ​ $ 41.90 ​ Granted 103 ​ $ 82.92 ​ Vested (6) ​ $ 29.94 ​ Forfeited or canceled (15) ​ $ 40.05 ​ Outstanding at December 31, 2021 383 ​ $ 53.14 ​ ​ Granted 110 ​ $ 78.96 ​ Vested (135) ​ $ 34.09 ​ Forfeited or canceled (122) ​ $ 49.68 ​ Outstanding at December 31, 2022 236 ​ $ 77.82 ​ Granted 146 ​ $ 80.92 ​ Vested (23) ​ $ 49.68 ​ Forfeited or canceled (103) ​ $ 82.92 ​ Outstanding at December 31, 2023 256 ​ $ 80.08 1.57 ​ $ 20,987 Outstanding and expected to vest at December 31, 2023 — ​ ​ ​ ​ — ​ $ —

SIGNIFICANT CUSTOMERS AND GEO_2

SIGNIFICANT CUSTOMERS AND GEOGRAPHIC NET REVENUES (Tables)	12 Months Ended
	Dec. 31, 2023
Concentration Risk [Line Items]
Schedules of Geographic Net Revenues	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, (In thousands) 2023 2022 2021 United States of America ​ $ 8,676 ​ $ 25,500 ​ $ 17,238 Hong Kong/China ​ 265,936 ​ 356,865 ​ 446,980 India ​ ​ 34,558 ​ ​ 33,159 ​ ​ 25,961 Taiwan ​ 15,774 ​ 19,789 ​ 25,991 Korea ​ 24,956 ​ 52,074 ​ 59,501 Western Europe (excluding Germany) ​ 27,819 ​ 32,429 ​ 35,835 Japan ​ 16,177 ​ 34,924 ​ 25,101 Germany ​ 23,041 ​ 52,876 ​ 32,664 Other ​ 27,601 ​ 43,522 ​ 34,006 Total net revenues ​ $ 444,538 ​ $ 651,138 ​ $ 703,277
Net revenue
Concentration Risk [Line Items]
Schedules of Concentration of Risk, by Risk Factor	The following customers represented 10% or more of the Company’s net revenues for the respective years ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, Customer 2023 ​ 2022 ​ 2021 Avnet ​ 27 % ​ 31 % ​ 30 % Honestar Technologies Co., Ltd. ​ 18 % ​ 11 % ​ 16 % Salcomp Group 10 % ​ * ​ ​ * ​ * Total customer revenue was less than 10% of net revenues.
Accounts receivable
Concentration Risk [Line Items]
Schedules of Concentration of Risk, by Risk Factor	The following customers represented 10% or more of accounts receivable: ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, Customer 2023 ​ 2022 Avnet ​ 39 % ​ 42 % Honestar Technologies Co., Ltd. ​ 20 % ​ * ​ Salcomp Group 10 % ​ 13 % Flextronics Group * ​ ​ 11 % * Total customer accounts receivable was less than 10% of accounts receivable.

COMMON STOCK REPURCHASES AND _2

COMMON STOCK REPURCHASES AND CASH DIVIDENDS (Tables)	12 Months Ended
	Dec. 31, 2023
COMMON STOCK REPURCHASES AND CASH DIVIDENDS
Schedule of Dividends Declared and Paid	The following table presents the quarterly dividends declared per share of the Company’s common stock for the periods indicated: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2023 2022 2021 First Quarter ​ $ 0.19 ​ $ 0.18 ​ $ 0.13 Second Quarter ​ $ 0.19 ​ $ 0.18 ​ $ 0.13 Third Quarter ​ $ 0.19 ​ $ 0.18 ​ $ 0.13 Fourth Quarter ​ $ 0.20 ​ $ 0.18 ​ $ 0.15

EARNINGS PER SHARE (Tables)

EARNINGS PER SHARE (Tables)	12 Months Ended
	Dec. 31, 2023
EARNINGS PER SHARE
Schedule of Earnings per share calculation	A summary of the earnings per share calculation is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, (In thousands, except per share amounts) 2023 2022 2021 Basic earnings per share: ​ ​ ​ Net income ​ $ 55,735 ​ $ 170,851 ​ $ 164,413 Weighted-average common shares ​ 57,195 ​ 57,801 ​ 60,327 Basic earnings per share ​ $ 0.97 ​ $ 2.96 ​ $ 2.73 Diluted earnings per share: (1) ​ ​ ​ Net income ​ $ 55,735 ​ $ 170,851 ​ $ 164,413 Weighted-average common shares ​ 57,195 ​ 57,801 ​ 60,327 Effect of dilutive awards: ​ ​ ​ Employee stock plans ​ 427 ​ 570 ​ 1,140 Diluted weighted-average common shares ​ 57,622 ​ 58,371 ​ 61,467 Diluted earnings per share ​ $ 0.97 ​ $ 2.93 ​ $ 2.67 (1) The Company includes the shares underlying performance-based awards in the calculation of diluted earnings per share if the performance conditions have been satisfied as of the end of the reporting period and excludes such shares when the necessary conditions have not been met. The Company has included in the 2023, 2022 and 2021 calculations those shares that were contingently issuable upon the satisfaction of the performance conditions as of the end of the respective periods.

PROVISION (BENEFIT) FOR INCOM_2

PROVISION (BENEFIT) FOR INCOME TAXES (Tables)	12 Months Ended
	Dec. 31, 2023
PROVISION (BENEFIT) FOR INCOME TAXES
U.S. and foreign components of income before income taxes	U.S. and foreign components of income before income taxes were: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, (In thousands) 2023 2022 2021 U.S. operations ​ $ 2,995 ​ $ 17,250 ​ $ 241 Foreign operations ​ 42,912 ​ 166,176 ​ 175,894 Total income before income taxes ​ $ 45,907 ​ $ 183,426 ​ $ 176,135
Components of provision (benefit) for income taxes	The components of the provision (benefit) for income taxes are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, (In thousands) 2023 2022 2021 Current provision (benefit): ​ ​ ​ Federal ​ $ (1,193) ​ $ 19,740 ​ $ 23,648 State ​ 3 ​ 2 ​ 2 Foreign ​ 1,331 ​ 1,079 ​ 1,608 ​ ​ 141 ​ 20,821 ​ 25,258 Deferred provision (benefit): ​ ​ ​ Federal ​ (9,178) ​ (7,962) ​ (11,449) State ​ — ​ — ​ — Foreign ​ (791) ​ (284) ​ (2,087) ​ ​ (9,969) ​ (8,246) ​ (13,536) Total ​ $ (9,828) ​ $ 12,575 ​ $ 11,722 ​
Effective income tax rate reconciliation	The provision (benefit) for income taxes differs from the amount that would result by applying the applicable federal income tax rate to income before income taxes, as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2023 ​ 2022 ​ 2021 Provision (benefit) computed at Federal statutory rate 21.0 % ​ 21.0 % ​ 21.0 % Business tax credits (12.2) ​ (3.7) ​ (3.6) Stock-based compensation (0.1) ​ (1.6) ​ (0.6) Foreign income taxed at different rate (17.6) ​ (18.5) ​ (23.8) GILTI inclusion 4.1 ​ 8.5 ​ 13.1 Uncertain tax positions (18.6) ​ (0.1) ​ (0.6) Valuation allowance 4.3 ​ 1.3 ​ 1.3 Other (2.3) ​ — ​ (0.1) Total (21.4) % ​ 6.9 % ​ 6.7 %
Components of net deferred income tax assets (liabilities)	The components of the net deferred income tax assets (liabilities) were as follows: ​ ​ ​ ​ ​ ​ ​ ​ December 31, (In thousands) ​ 2023 ​ 2022 Deferred tax assets: ​ ​ Capitalized R&D costs ​ $ 30,886 ​ $ 20,666 Other reserves and accruals ​ ​ 861 ​ ​ 2,516 Tax credit carry-forwards ​ 28,223 ​ 26,154 Stock compensation ​ 1,543 ​ 1,559 Capital losses ​ 141 ​ 150 Net operating loss ​ 2,269 ​ 2,217 Other ​ 465 ​ 439 Valuation allowance ​ (31,031) ​ (29,036) ​ ​ 33,357 ​ 24,665 Deferred tax liabilities: ​ ​ Depreciation ​ (5,040) ​ (5,596) ​ ​ (5,040) ​ (5,596) Net deferred tax assets ​ $ 28,317 ​ $ 19,069 ​
Unrecognized tax benefits rollforward	The Company applies the provisions of ASC 740-10, relating to accounting for uncertain income taxes. Reconciliation of the beginning and ending amount of unrecognized tax benefits: ​ ​ ​ ​ ​ Unrecognized (In thousands) ​ Tax Benefits Unrecognized tax benefits balance at January 1, 2021 ​ $ 21,051 Gross increase for tax positions of current year ​ 2,068 Gross decrease for tax positions of prior years ​ ​ — Statute of limitation release for tax positions of prior years ​ (1,756) Unrecognized tax benefits balance at December 31, 2021 ​ 21,363 Gross increase for tax positions of current year ​ 2,188 Gross decrease for tax positions of prior years ​ ​ — Statute of limitation release for tax positions of prior years ​ (165) Unrecognized tax benefits balance at December 31, 2022 ​ 23,386 Gross increase for tax positions of current year ​ 605 Gross decrease for tax positions of prior years ​ ​ — Statute of limitation release for tax positions of prior years ​ (7,602) Unrecognized tax benefits balance at December 31, 2023 ​ $ 16,389

LEASES AND COMMITMENTS (Tables)

LEASES AND COMMITMENTS (Tables)	12 Months Ended
	Dec. 31, 2023
LEASES AND COMMITMENTS
Supplemental Balance Sheet Information of Operating Leases	Balance sheet information related to leases was as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, (In thousands) ​ Balance Sheet Classification ​ 2023 ​ 2022 Right-of-use assets ​ ​ ​ ​ ​ ​ Operating lease assets ​ Other assets ​ $ 10,398 ​ $ 9,153 ​ ​ ​ ​ ​ ​ ​ ​ ​ Lease liabilities ​ ​ ​ Current operating lease liabilities ​ Other accrued liabilities ​ $ 2,626 ​ $ 2,895 Non-current operating lease liabilities ​ Other liabilities ​ 7,354 ​ 5,831 Total ​ ​ ​ $ 9,980 ​ $ 8,726
Lease Terms and Discount Rate	​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, Lease term and discount rate ​ 2023 ​ 2022 Weighted average remaining lease term ​ 3.8 years ​ 4.0 years Weighted average discount rate 6.1 % ​ 4.6 %
Supplemental Cash Flow Information Related to Leases	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, (In thousands) ​ 2023 ​ 2022 Cash paid for amounts included in the measurement of lease liabilities: ​ ​ ​ ​ ​ Operating cash flows from operating leases ​ $ 3,579 ​ $ 3,245 Right-of-use assets obtained in exchange for new operating lease obligations ​ $ 4,889 ​ $ 1,795
Lessee, Operating Lease, Liability, Maturity	​ ​ ​ ​ ​ ​ December 31, (In thousands) ​ 2023 2024 ​ $ 3,168 2025 ​ 3,103 2026 ​ 2,514 2027 ​ 1,359 2028 ​ ​ 852 Thereafter ​ 243 Total future minimum lease payments ​ 11,239 Less imputed interest ​ (1,259) Total ​ $ 9,980

SIGNIFICANT ACCOUNTING POLICI_3

SIGNIFICANT ACCOUNTING POLICIES AND RECENT ACCOUNTING PRONOUNCEMENTS (Segment Reporting) (Details)	12 Months Ended
	Dec. 31, 2023 segment
Segment Reporting [Abstract]
Number of reportable segments	1

SIGNIFICANT ACCOUNTING POLICI_4

SIGNIFICANT ACCOUNTING POLICIES AND RECENT ACCOUNTING PRONOUNCEMENTS (Significant Accounting Policies) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Employee Benefits Plan
Defined Contribution Plan, Employer Discretionary Contribution Amount	$ 2.1	$ 2	$ 1.9
Foreign Exchange Transactions
Foreign Currency Transaction Gain (Loss), before Tax	$ (0.4)		(0.6)
Warranty
Product Warranty Period	P12M
Advertising Expense
Advertising Expense	$ 1.3	$ 1.4	$ 1.3

COMPONENTS OF THE COMPANY'S C_3

COMPONENTS OF THE COMPANY'S CONSOLIDATED BALANCE SHEETS (Accounts Receivable) (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
COMPONENTS OF THE COMPANY'S CONSOLIDATED BALANCE SHEETS
Accounts receivable trade	$ 53,147	$ 78,914
Allowance for ship and debit	(36,017)	(53,184)
Allowance for stock rotation and rebate	(1,775)	(3,759)
Allowance for credit losses	(681)	(1,135)	$ (445)
Total	$ 14,674	$ 20,836

COMPONENTS OF THE COMPANY'S C_4

COMPONENTS OF THE COMPANY'S CONSOLIDATED BALANCE SHEETS (Allowance for Estimated Credit Losses) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Allowance for estimated credit losses
Beginning Balance	$ (1,135)	$ (445)
Provision for credit loss expense	(619)	(1,859)
Receivables written off		49
Recoveries collected	1,073	1,120
Ending Balance	$ (681)	$ (1,135)

COMPONENTS OF THE COMPANY'S C_5

COMPONENTS OF THE COMPANY'S CONSOLIDATED BALANCE SHEETS (Inventories) (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Inventory, Net [Abstract]
Raw materials	$ 96,467	$ 75,355
Work-in-process	24,727	15,440
Finished goods	41,970	44,625
Total	$ 163,164	$ 135,420

COMPONENTS OF THE COMPANY'S C_6

COMPONENTS OF THE COMPANY'S CONSOLIDATED BALANCE SHEETS (Property and Equipment) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Property, Plant and Equipment [Line Items]
Property and Equipment, Gross	$ 466,640	$ 446,947
Less: Accumulated depreciation	(302,427)	(270,266)
PROPERTY AND EQUIPMENT, net	164,213	176,681
Depreciation	35,203	34,930	$ 31,454
Property and Equipment | Geographic Concentration Risk | United States of America
Property, Plant and Equipment [Line Items]
Property and Equipment, Gross	$ 203,600	$ 190,300	$ 174,600
Property and Equipment | Geographic Concentration Risk | Thailand
Property, Plant and Equipment [Line Items]
Concentration risk percentage	11%	12%	14%
Property and Equipment | Geographic Concentration Risk | Malaysia
Property, Plant and Equipment [Line Items]
Concentration risk percentage	15%	15%	15%
Land
Property, Plant and Equipment [Line Items]
Property and Equipment, Gross	$ 22,178	$ 22,166
Construction-in-progress
Property, Plant and Equipment [Line Items]
Property and Equipment, Gross	17,022	19,195
Building and improvements
Property, Plant and Equipment [Line Items]
Property and Equipment, Gross	92,049	89,704
Machinery and equipment
Property, Plant and Equipment [Line Items]
Property and Equipment, Gross	267,941	253,308
Computer software and hardware and office furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and Equipment, Gross	$ 67,450	$ 62,574
Minimum | Building and improvements
Property, Plant and Equipment [Line Items]
Property and Equipment, Useful Life	4 years
Minimum | Machinery and equipment
Property, Plant and Equipment [Line Items]
Property and Equipment, Useful Life	2 years
Minimum | Computer software and hardware and office furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and Equipment, Useful Life	4 years
Maximum | Building and improvements
Property, Plant and Equipment [Line Items]
Property and Equipment, Useful Life	40 years
Maximum | Machinery and equipment
Property, Plant and Equipment [Line Items]
Property and Equipment, Useful Life	8 years
Maximum | Computer software and hardware and office furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and Equipment, Useful Life	7 years

COMPONENTS OF THE COMPANY'S C_7

COMPONENTS OF THE COMPANY'S CONSOLIDATED BALANCE SHEETS (Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	$ (7,344)	$ (3,737)	$ (2,163)
Other comprehensive income (loss) before reclassifications	5,970	(3,684)	(1,741)
Amounts reclassified from accumulated other comprehensive loss	(88)	77	167
Other comprehensive income (loss)	5,882	(3,607)	(1,574)
Ending balance	(1,462)	(7,344)	(3,737)
Unrealized Gains and Losses on Marketable Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(5,323)	(1,165)	890
Other comprehensive income (loss) before reclassifications	5,579	(4,158)	(2,055)
Amounts reclassified from accumulated other comprehensive loss	0	0	0
Other comprehensive income (loss)	5,579	(4,158)	(2,055)
Ending balance	256	(5,323)	(1,165)
Defined Benefit Pension Items
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	862	(674)	(1,641)
Other comprehensive income (loss) before reclassifications	811	1,459	800
Amounts reclassified from accumulated other comprehensive loss	(88)	77	167
Other comprehensive income (loss)	723	1,536	967
Ending balance	1,585	862	(674)
Foreign Currency Items
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(2,883)	(1,898)	(1,412)
Other comprehensive income (loss) before reclassifications	(420)	(985)	(486)
Amounts reclassified from accumulated other comprehensive loss	0	0	0
Other comprehensive income (loss)	(420)	(985)	(486)
Ending balance	$ (3,303)	$ (2,883)	$ (1,898)

FAIR VALUE MEASUREMENTS (Detail

FAIR VALUE MEASUREMENTS (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Investments at Fair Value	$ 267,688	$ 307,487
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Investments at Fair Value	491	363
Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Investments at Fair Value	267,197	307,124
Corporate securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments at Fair Value	246,922	248,441
Corporate securities | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments at Fair Value	0	0
Corporate securities | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments at Fair Value	246,922	248,441
Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments at Fair Value	20,275	58,683
Commercial paper | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments at Fair Value	0	0
Commercial paper | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments at Fair Value	20,275	58,683
Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments at Fair Value	491	363
Money market funds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments at Fair Value	491	363
Money market funds | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments at Fair Value	$ 0	$ 0

MARKETABLE SECURITIES (Details)

MARKETABLE SECURITIES (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 247,384	$ 253,764
Gross Unrealized Gains	967	71
Gross Unrealized Losses	(711)	(5,394)
Estimated Fair Market Value	$ 247,640	$ 248,441
Weighted average interest rate on investments	4.87%	2.08%
Interest receivable	$ 2,300	$ 1,200
Investments due in 3 months or less:
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	10,688	21,803
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(42)	(135)
Estimated Fair Market Value	10,646	21,668
Investments due in 4-12 months:
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	49,398	173,833
Gross Unrealized Gains	15	0
Gross Unrealized Losses	(347)	(4,019)
Estimated Fair Market Value	49,066	169,814
Investments due in 12 months or greater:
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	187,298	58,128
Gross Unrealized Gains	952	71
Gross Unrealized Losses	(322)	(1,240)
Estimated Fair Market Value	187,928	56,959
Commercial paper | Investments due in 4-12 months:
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	718
Gross Unrealized Gains	0
Gross Unrealized Losses	0
Estimated Fair Market Value	718
Corporate securities | Investments due in 3 months or less:
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	10,688	21,803
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(42)	(135)
Estimated Fair Market Value	10,646	21,668
Corporate securities | Investments due in 4-12 months:
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	48,680	173,833
Gross Unrealized Gains	15	0
Gross Unrealized Losses	(347)	(4,019)
Estimated Fair Market Value	48,348	169,814
Corporate securities | Investments due in 12 months or greater:
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	187,298	58,128
Gross Unrealized Gains	952	71
Gross Unrealized Losses	(322)	(1,240)
Estimated Fair Market Value	$ 187,928	$ 56,959

MARKETABLE SECURITIES (Continuo

MARKETABLE SECURITIES (Continuous Unrealized Loss Position) (Details) - USD ($)	Dec. 31, 2023	Dec. 31, 2022
Debt Securities, Available-for-sale [Line Items]
Less Than 12 Months Estimated Fair Market Value, Total marketable securities	$ 102,729,000	$ 45,047,000
Less Than 12 Months Gross Unrealized Losses, Total marketable securities	(371,000)	(662,000)
12 Months or Longer Estimated Fair Market Value, Total marketable securities	25,401,000	191,443,000
12 Months or Longer Gross Unrealized Losses, Total marketable securities	(340,000)	(4,732,000)
Total Estimated Fair Market Value, Total marketable securities	128,130,000	236,490,000
Total Gross Unrealized Losses, Total marketable securities	(711,000)	(5,394,000)
Debt Securities, Available-for-sale, Allowance for Credit Loss	0	0
Corporate securities
Debt Securities, Available-for-sale [Line Items]
Less Than 12 Months Estimated Fair Market Value, Total marketable securities	102,729,000	45,047,000
Less Than 12 Months Gross Unrealized Losses, Total marketable securities	(371,000)	(662,000)
12 Months or Longer Estimated Fair Market Value, Total marketable securities	25,401,000	191,443,000
12 Months or Longer Gross Unrealized Losses, Total marketable securities	(340,000)	(4,732,000)
Total Estimated Fair Market Value, Total marketable securities	128,130,000	236,490,000
Total Gross Unrealized Losses, Total marketable securities	$ (711,000)	$ (5,394,000)

MARKETABLE SECURITIES - Unreali

MARKETABLE SECURITIES - Unrealized Losses (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
MARKETABLE SECURITIES
Unrealized losses on marketable securities	$ 0	$ 0

GOODWILL AND INTANGIBLE ASSET_2

GOODWILL AND INTANGIBLE ASSETS Goodwill (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Goodwill [Abstract]
Goodwill	$ 91,849	$ 91,849

GOODWILL AND INTANGIBLE ASSET_3

GOODWILL AND INTANGIBLE ASSETS (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Intangible Assets and Goodwill [Line Items]
Amortization of intangibles	$ 2,173	$ 2,415	$ 3,494
Intangible Assets, Net[Abstract]
Intangible Assets, Gross	41,147	41,147
Accumulated amortization	(36,723)	(34,550)
Total	3,163
Total Intangible Assets, Net	$ 4,424	6,597
Minimum
Intangible Assets and Goodwill [Line Items]
Useful life (in years)	2 years
Maximum
Intangible Assets and Goodwill [Line Items]
Useful life (in years)	12 years
Developed technology
Intangible Assets, Net[Abstract]
Finite-Lived Intangible Assets, Gross	$ 37,960	37,960
Accumulated amortization	(35,459)	(33,531)
Total	2,501	4,429
Technology licenses
Intangible Assets, Net[Abstract]
Finite-Lived Intangible Assets, Gross	1,926	1,926
Accumulated amortization	(1,264)	(1,019)
Total	662	907
Domain name
Intangible Assets, Net[Abstract]
Indefinite-Lived Intangible Assets	1,261	1,261
Accumulated amortization	$ 0	$ 0

GOODWILL AND INTANGIBLE ASSET_4

GOODWILL AND INTANGIBLE ASSETS (Intangible Assets Amortization Expense) (Details) $ in Thousands	Dec. 31, 2023 USD ($)
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
2024	$ 1,279
2025	832
2026	687
2027	365
Total	$ 3,163

STOCK PLANS AND SHARE BASED C_4

STOCK PLANS AND SHARE BASED COMPENSATION (Details) $ in Thousands, shares in Millions	12 Months Ended
	Dec. 31, 2023 USD ($) plan period shares	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of stock-based compensation plans | plan	3
Number of shares available for future issuance	4.4
Stock-based compensation expense | $	$ 28,528	$ 22,364	$ 37,609
2016 Incentive Award Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period	3.4
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	3.6
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards vesting period	4 years
Stock-based compensation expense | $	$ 23,400	23,200	19,900
Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum percentage of employee's compensation eligible for payroll deductions	15%
Purchase price of the purchase plan as percentage of the lower of the fair market value on the first day of each offering period or on the purchase date	85%
Number of purchase periods in each offering period | period	1
Duration of each purchase period in each offering period	6 months
Shares reserved for issuance	7.5
Number of shares purchased	6.9
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	0.6
Stock-based compensation expense | $	$ 1,900	1,900	2,000
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards vesting period	4 years
Performance Based Awards, Long-term and Short-term
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense | $	$ 3,200	$ (2,700)	$ 15,700

STOCK PLANS AND SHARE BASED C_5

STOCK PLANS AND SHARE BASED COMPENSATION (Stock-Based Compensation) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Stock-based compensation expense for stock options, stock awards and employee stock purchases included in operations:
Stock-based compensation expense	$ 28,528	$ 22,364	$ 37,609
Unrecognized Compensation Expense for Unvested Awards	47,011
Long-Term Performance-Based Awards (PRSUs)
Stock-based compensation expense for stock options, stock awards and employee stock purchases included in operations:
Unrecognized Compensation Expense for Unvested Awards	$ 0
Weighted Average Remaining Recognition Period	0 years
Restricted Stock Units (RSUs)
Stock-based compensation expense for stock options, stock awards and employee stock purchases included in operations:
Stock-based compensation expense	$ 23,400	23,200	19,900
Unrecognized Compensation Expense for Unvested Awards	$ 46,856
Weighted Average Remaining Recognition Period	2 years 7 months 28 days
Employee Stock Purchase Plan
Stock-based compensation expense for stock options, stock awards and employee stock purchases included in operations:
Stock-based compensation expense	$ 1,900	1,900	2,000
Unrecognized Compensation Expense for Unvested Awards	$ 155
Weighted Average Remaining Recognition Period	29 days
Performance Based Awards, Long-term and Short-term
Stock-based compensation expense for stock options, stock awards and employee stock purchases included in operations:
Stock-based compensation expense	$ 3,200	(2,700)	15,700
Cost of revenues
Stock-based compensation expense for stock options, stock awards and employee stock purchases included in operations:
Stock-based compensation expense	1,692	1,132	2,359
Research and development
Stock-based compensation expense for stock options, stock awards and employee stock purchases included in operations:
Stock-based compensation expense	10,939	10,428	12,127
Sales and marketing
Stock-based compensation expense for stock options, stock awards and employee stock purchases included in operations:
Stock-based compensation expense	6,888	6,035	7,630
General and administrative
Stock-based compensation expense for stock options, stock awards and employee stock purchases included in operations:
Stock-based compensation expense	$ 9,009	$ 4,769	$ 15,493

STOCK PLANS AND SHARE BASED C_6

STOCK PLANS AND SHARE BASED COMPENSATION (Fair Value Assumptions) (Details) - Employee Stock Purchase Plan - $ / shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rates	5.15%	1.71%	0.07%
Expected volatility rates	37%	41%	41%
Expected dividend yield	0.90%	0.89%	0.57%
Expected term of purchase rights (in years)	5 months 26 days	6 months	6 months
Weighted-average estimated fair value of purchase rights	$ 23.75	$ 21.63	$ 23.92

STOCK PLANS AND SHARE BASED C_7

STOCK PLANS AND SHARE BASED COMPENSATION (Option Activity) (Details) - Employee Stock Option [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Option activity under the Plans
Stock options granted	0
Exercised	0
Stock option shares outstanding	0
Total intrinsic value of options exercised		$ 0.8	$ 4.9

STOCK PLANS AND SHARE BASED C_8

STOCK PLANS AND SHARE BASED COMPENSATION (Performance-based Awards and Restricted Stock Units) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Performance Based Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of performance-based awards shares released as a percentage of target number, minimum	0%
Number of performance-based awards shares released as a percentage of target number, maximum	200%
Shares
Outstanding, shares at beginning of the period	34,000	104,000	150,000
Granted, shares	131,000	119,000	105,000
Vested, shares	(34,000)	(104,000)	(150,000)
Forfeited, shares	(93,000)	(85,000)	(1,000)
Outstanding, shares at ending of the period	38,000	34,000	104,000
Outstanding, weighted-average grant date fair value per share, beginning of period	$ 79.94	$ 84.47	$ 46.27
Granted, weighted-average grant date fair value per share	82.96	79.91	84.48
Vested, weighted-average grant date fair value per share	79.94	84.48	46.27
Forfeited or expired, weighted-average grant date fair value per share	82.96	79.89	85.01
Outstanding, weighted-average grant date fair value per share, end of period	$ 82.95	$ 79.94	$ 84.47
Outstanding, weighted-average remaining contractual term (in years)	0 years
Outstanding, aggregate intrinsic value	$ 3,131
Outstanding and expected to vest, shares	38,000
Outstanding and expected to vest, weighted-average remaining contractual term (in years)	0 years
Outstanding and expected to vest, aggregate intrinsic value	$ 3,131
Grant date fair value of awards released	$ 2,700	$ 8,800	$ 6,900
Long-Term Performance-Based Awards (PRSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of performance-based awards shares released as a percentage of target number, minimum	0%
Number of performance-based awards shares released as a percentage of target number, maximum	200%
Performance period	3 years
Shares
Outstanding, shares at beginning of the period	236,000	383,000	301,000
Granted, shares	146,000	110,000	103,000
Vested, shares	(23,000)	(135,000)	(6,000)
Forfeited, shares	(103,000)	(122,000)	(15,000)
Outstanding, shares at ending of the period	256,000	236,000	383,000
Outstanding, weighted-average grant date fair value per share, beginning of period	$ 77.82	$ 53.14	$ 41.90
Granted, weighted-average grant date fair value per share	80.92	78.96	82.92
Vested, weighted-average grant date fair value per share	49.68	34.09	29.94
Forfeited or expired, weighted-average grant date fair value per share	82.92	49.68	40.05
Outstanding, weighted-average grant date fair value per share, end of period	$ 80.08	$ 77.82	$ 53.14
Outstanding, weighted-average remaining contractual term (in years)	1 year 6 months 25 days
Outstanding, aggregate intrinsic value	$ 20,987
Outstanding and expected to vest, shares	0
Outstanding and expected to vest, weighted-average remaining contractual term (in years)	0 years
Grant date fair value of awards released	$ 1,100	$ 4,600	$ 200
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards vesting period	4 years
Shares
Outstanding, shares at beginning of the period	1,096,000	1,144,000	1,518,000
Granted, shares	335,000	519,000	271,000
Vested, shares	(418,000)	(481,000)	(546,000)
Forfeited, shares	(32,000)	(86,000)	(99,000)
Outstanding, shares at ending of the period	981,000	1,096,000	1,144,000
Outstanding, weighted-average grant date fair value per share, beginning of period	$ 60.52	$ 46.81	$ 35.51
Granted, weighted-average grant date fair value per share	80.97	76.01	83.79
Vested, weighted-average grant date fair value per share	53.08	44.70	35.03
Forfeited or expired, weighted-average grant date fair value per share	73.29	60.02	39.85
Outstanding, weighted-average grant date fair value per share, end of period	$ 70.27	$ 60.52	$ 46.81
Outstanding, weighted-average remaining contractual term (in years)	1 year 5 months 23 days
Outstanding, aggregate intrinsic value	$ 80,585
Outstanding and expected to vest, shares	918,000
Outstanding and expected to vest, weighted-average remaining contractual term (in years)	1 year 4 months 20 days
Outstanding and expected to vest, aggregate intrinsic value	$ 75,384
Grant date fair value of awards released	$ 22,200	$ 21,500	$ 19,100

SIGNIFICANT CUSTOMERS AND GEO_3

SIGNIFICANT CUSTOMERS AND GEOGRAPHIC NET REVENUES (Customer and Credit Risk Concentration) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($) customer	Dec. 31, 2022 USD ($) customer	Dec. 31, 2021 USD ($) customer
Concentration Risk [Line Items]
NET REVENUES | $	$ 444,538	$ 651,138	$ 703,277
Distributors
Concentration Risk [Line Items]
NET REVENUES | $	$ 307,400	$ 457,700	$ 525,700
Credit concentration risk | Accounts receivable
Concentration Risk [Line Items]
Number of major customers | customer	10	10
Credit concentration risk | Accounts receivable | Avnet
Concentration Risk [Line Items]
Concentration risk percentage	39%	42%
Credit concentration risk | Accounts receivable | Honestar Technologies Co., Ltd.
Concentration Risk [Line Items]
Concentration risk percentage	20%
Credit concentration risk | Accounts receivable | Salcomp Group
Concentration Risk [Line Items]
Concentration risk percentage	10%	13%
Credit concentration risk | Accounts receivable | Flextronics Group
Concentration Risk [Line Items]
Concentration risk percentage		11%
Credit concentration risk | Accounts receivable | Ten Customers
Concentration Risk [Line Items]
Concentration risk percentage	86%	87%
Customer concentration risk | Net revenue
Concentration Risk [Line Items]
Number of major customers | customer	10	10	10
Concentration risk, percentage of total net revenues	80%	76%	78%
Customer concentration risk | Net revenue | Avnet
Concentration Risk [Line Items]
Concentration risk, percentage of total net revenues	27%	31%	30%
Customer concentration risk | Net revenue | Honestar Technologies Co., Ltd.
Concentration Risk [Line Items]
Concentration risk, percentage of total net revenues	18%	11%	16%
Customer concentration risk | Net revenue | Salcomp Group
Concentration Risk [Line Items]
Concentration risk, percentage of total net revenues	10%

SIGNIFICANT CUSTOMERS AND GEO_4

SIGNIFICANT CUSTOMERS AND GEOGRAPHIC NET REVENUES (Geographic Net Revenues) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Schedule of Revenues by Geography [Line Items]
NET REVENUES	$ 444,538	$ 651,138	$ 703,277
United States of America
Schedule of Revenues by Geography [Line Items]
NET REVENUES	8,676	25,500	17,238
Hong Kong/China
Schedule of Revenues by Geography [Line Items]
NET REVENUES	265,936	356,865	446,980
India
Schedule of Revenues by Geography [Line Items]
NET REVENUES	34,558	33,159	25,961
Taiwan
Schedule of Revenues by Geography [Line Items]
NET REVENUES	15,774	19,789	25,991
Korea
Schedule of Revenues by Geography [Line Items]
NET REVENUES	24,956	52,074	59,501
Western Europe (excluding Germany)
Schedule of Revenues by Geography [Line Items]
NET REVENUES	27,819	32,429	35,835
Japan
Schedule of Revenues by Geography [Line Items]
NET REVENUES	16,177	34,924	25,101
Germany
Schedule of Revenues by Geography [Line Items]
NET REVENUES	23,041	52,876	32,664
Other
Schedule of Revenues by Geography [Line Items]
NET REVENUES	$ 27,601	$ 43,522	$ 34,006

COMMON STOCK REPURCHASES AND _3

COMMON STOCK REPURCHASES AND CASH DIVIDENDS (Common Stock Repurchases) (Details) - USD ($) $ in Thousands, shares in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Oct. 31, 2022	Apr. 30, 2022	Feb. 28, 2022	Jan. 31, 2022	Oct. 31, 2021	Apr. 30, 2021	Oct. 31, 2018
Class of Stock [Line Items]
Stock Repurchase Program, Authorized Amount				$ 100,000	$ 75,000	$ 50,000	$ 100,000	$ 50,000	$ 50,000	$ 80,000
Stock Repurchased and Retired During Period, Value	$ 55,349	$ 311,094	$ 73,938
Common Stock
Class of Stock [Line Items]
Stock Repurchased and Retired During Period, Shares	0.8	3.8	0.9
Stock Repurchased and Retired During Period, Value	$ 55,300	$ 311,100	$ 73,900
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 26,000

COMMON STOCK REPURCHASES AND _4

COMMON STOCK REPURCHASES AND CASH DIVIDENDS (Cash Dividends) (Details) $ / shares in Units, $ in Thousands	1 Months Ended					3 Months Ended												12 Months Ended
	Oct. 31, 2023 item $ / shares	Feb. 28, 2023 $ / shares	Jan. 31, 2022 dividend $ / shares	Oct. 31, 2021 item $ / shares	Jan. 31, 2021 $ / shares	Dec. 31, 2023 $ / shares	Sep. 30, 2023 $ / shares	Jun. 30, 2023 $ / shares	Mar. 31, 2023 $ / shares	Dec. 31, 2022 $ / shares	Sep. 30, 2022 $ / shares	Jun. 30, 2022 $ / shares	Mar. 31, 2022 $ / shares	Dec. 31, 2021 $ / shares	Sep. 30, 2021 $ / shares	Jun. 30, 2021 $ / shares	Mar. 31, 2021 $ / shares	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
COMMON STOCK REPURCHASES AND CASH DIVIDENDS
Common Stock, Dividends, Per Share, Declared						$ 0.20	$ 0.19	$ 0.19	$ 0.19	$ 0.18	$ 0.18	$ 0.18	$ 0.18	$ 0.15	$ 0.13	$ 0.13	$ 0.13
Payments of dividends to stockholders | $																		$ 44,008	$ 41,492	$ 32,599
Common Stock, Dividends, Number of Quarterly Distributions Declared	4		4	5
Common Stock, Dividends, Per Share, Declared, Two Fiscal Years Prior, Each Quarter					$ 0.13
Common Stock, Dividends, Per Share, Declared, Two Fiscal Years Prior, Fourth Quarter				$ 0.15
Common Stock, Dividends, Increase Per Share, Declared, Prior Fiscal Year, Each Quarter			$ 0.03
Common Stock, Dividends, Per Share, Declared, Prior Fiscal Year, Each Quarter			$ 0.18	$ 0.15
Common Stock, Dividends, Per Share, Declared, Current Fiscal Year, Each Quarter		$ 0.19
Common Stock, Dividends Per Share Declared, Current Fiscal Year, Fourth Quarter	$ 0.20
Common Stock, Dividends, Per Share, Declared, Next Fiscal Year, Each Quarter	$ 0.20

EARNINGS PER SHARE (Details)

EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Basic earnings per share:
Net income	$ 55,735	$ 170,851	$ 164,413
Weighted-average common shares	57,195	57,801	60,327
Basic earnings per share	$ 0.97	$ 2.96	$ 2.73
Diluted earnings per share:
Net income	$ 55,735	$ 170,851	$ 164,413
Weighted-average common shares	57,195	57,801	60,327
Effect of dilutive awards:
Employee stock plans	427	570	1,140
Diluted weighted-average common shares	57,622	58,371	61,467
Diluted earnings per share	$ 0.97	$ 2.93	$ 2.67
Stock awards excluded in the computation of diluted earnings per share	0	0	0

PROVISION (BENEFIT) FOR INCOM_3

PROVISION (BENEFIT) FOR INCOME TAXES (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
U.S. and foreign components of income before income taxes [Abstract]
U.S. operations	$ 2,995	$ 17,250	$ 241
Foreign operations	42,912	166,176	175,894
INCOME BEFORE INCOME TAXES	45,907	183,426	176,135
Current provision (benefit):
Federal	(1,193)	19,740	23,648
State	3	2	2
Foreign	1,331	1,079	1,608
Current provision (benefit)	141	20,821	25,258
Deferred provision (benefit):
Federal	(9,178)	(7,962)	(11,449)
State	0	0	0
Foreign	(791)	(284)	(2,087)
Deferred provision (benefit)	(9,969)	(8,246)	(13,536)
Income Tax Expense (Benefit), Total	$ (9,828)	$ 12,575	$ 11,722
Effective income tax rate reconciliation [Abstract]
Provision (benefit) computed at Federal statutory rate	21%	21%	21%
Business tax credits	(12.20%)	(3.70%)	(3.60%)
Stock-based compensation	(0.10%)	(1.60%)	(0.60%)
Foreign income taxed at different rate	(17.60%)	(18.50%)	(23.80%)
GILTI inclusion	4.10%	8.50%	13.10%
Uncertain tax positions	(18.60%)	(0.10%)	(0.60%)
Valuation allowance	4.30%	1.30%	1.30%
Other	(2.30%)		(0.10%)
Effective Income Tax Rate Reconciliation, Percent, Total	(21.40%)	6.90%	6.70%
Components of deferred income tax assets (liabilities) [Abstract]
Capitalized R&D costs	$ 30,886	$ 20,666
Other reserves and accruals	861	2,516
Tax credit carry-forwards	28,223	26,154
Stock compensation	1,543	1,559
Capital losses	141	150
Net operating loss	2,269	2,217
Other	465	439
Valuation allowance	(31,031)	(29,036)
Deferred tax assets, net of valuation allowance	33,357	24,665
Depreciation	(5,040)	(5,596)
Deferred tax liabilities	(5,040)	(5,596)
Net deferred tax assets	28,317	19,069
Reconciliation of the Beginning and Ending Amount of Unrecognized Tax Benefits [Roll Forward]
Unrecognized tax benefits, balance at beginning of period	23,386	21,363	$ 21,051
Gross increase for tax positions of current Year	605	2,188	2,068
Gross decrease for tax positions of prior years	0	0	0
Statute of limitation release for tax positions of prior years	(7,602)	(165)	(1,756)
Unrecognized tax benefits, balance at end of period	16,389	23,386	21,363
Unrecognized tax benefits [Abstract]
Unrecognized tax benefits, balance at end of period	16,389	23,386	$ 21,363
Income tax benefit that would be recorded if unrecognized tax benefits are recognized	4,500
Income tax interest and penalties accrued	300	$ 1,200
Federal
Unrecognized tax benefits [Abstract]
Unrecognized tax benefits, period increase	7,600
State and Local Jurisdiction | California Taxing Authority
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	44,200
Research Tax Credit Carryforward | State and Local Jurisdiction | California Taxing Authority
Operating Loss Carryforwards [Line Items]
Tax credit carryforward, amount	40,700
Research Tax Credit Carryforward | State and Local Jurisdiction | New Jersey Division of Taxation
Operating Loss Carryforwards [Line Items]
Tax credit carryforward, amount	800
Research Tax Credit Carryforward | Foreign Tax Authority
Operating Loss Carryforwards [Line Items]
Tax credit carryforward, amount	$ 3,800
Earliest Tax Year | State and Local Jurisdiction | California Taxing Authority
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards, Expiration Date	Jan. 01, 2032
Earliest Tax Year | Research Tax Credit Carryforward | State and Local Jurisdiction | New Jersey Division of Taxation
Operating Loss Carryforwards [Line Items]
Tax Credit Carryforward, Expiration Date	Jan. 01, 2029
Earliest Tax Year | Research Tax Credit Carryforward | Foreign Tax Authority
Operating Loss Carryforwards [Line Items]
Tax Credit Carryforward, Expiration Date	Jan. 01, 2030

LEASES AND COMMITMENTS (Leases

LEASES AND COMMITMENTS (Leases Expense and Balance Sheet Information of Operating Leases) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Leases [Abstract]
Operating Lease, Expense	$ 3,600	$ 3,300	$ 3,300
Operating Lease, Right-of-Use Asset	$ 10,398	$ 9,153
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	Other Assets, Noncurrent	Other Assets, Noncurrent
Operating Lease, Liability, Current	$ 2,626	$ 2,895
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Other Accrued Liabilities, Current	Other Accrued Liabilities, Current
Operating Lease, Liability, Noncurrent	$ 7,354	$ 5,831
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Other Liabilities, Noncurrent	Other Liabilities, Noncurrent
Operating Lease, Liability	$ 9,980	$ 8,726

LEASES AND COMMITMENTS Lease Te

LEASES AND COMMITMENTS Lease Terms and Discount Rate (Details)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Lease Terms and Discount Rate [Line Items]
Lessee, Operating Lease, Option Extension Term, Maximum	5 years
Lessee, Operating Lease, Option To Terminate, Minimum Term	1 year
Operating Lease, Weighted Average Remaining Lease Term	3 years 9 months 18 days	4 years
Lessee, Operating Lease, Discount Rate	6.10%	4.60%
Minimum
Lease Terms and Discount Rate [Line Items]
Lessee Operating Lease Remaining Lease Term Range	1 year
Maximum
Lease Terms and Discount Rate [Line Items]
Lessee Operating Lease Remaining Lease Term Range	6 years

LEASES AND COMMITMENTS Suppleme

LEASES AND COMMITMENTS Supplemental Cash Flows Information Regarding Operating Leases (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Leases [Abstract]
Operating cash flows from operating leases	$ 3,579	$ 3,245
Right-of-use assets obtained in exchange for new operating lease obligations	$ 4,889	$ 1,795

LEASES AND COMMITMENTS Maturiti

LEASES AND COMMITMENTS Maturities of Operating Lease Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Leases [Abstract]
2024	$ 3,168
2025	3,103
2026	2,514
2027	1,359
2028	852
Thereafter	243
Total future minimum lease payments	11,239
Less imputed interest	(1,259)
Total	$ 9,980	$ 8,726

LEASES AND COMMITMENTS Commitme

LEASES AND COMMITMENTS Commitments (Details)	Dec. 31, 2023 USD ($)
LEGAL PROCEEDINGS AND CONTINGENCIES
Unrecorded Unconditional Purchase Obligation	$ 0

LEGAL PROCEEDINGS AND CONTING_2

LEGAL PROCEEDINGS AND CONTINGENCIES (Details) - Pending Litigation - patent			12 Months Ended
	Oct. 31, 2022	Jan. 06, 2020	Dec. 31, 2023
Patent Infringement Claim One
Gain and Loss Contingencies [Line Items]
Gain Contingency, Patents Allegedly Infringed upon, Number		2	3
Patent Infringement Claim Two
Gain and Loss Contingencies [Line Items]
Loss Contingency, Patents Allegedly Infringed, Number	1

RETIREMENT PLANS (Details)

RETIREMENT PLANS (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Defined Benefit Plan Disclosure [Line Items]
Net Pension Liability	$ 3.5	$ 3.9
Plan Assets	7.9	8.2
Projected Benefit Obligation	11.4	12.1
Defined Benefit Plan, Estimated Future Employer Contributions in Next Fiscal Year	0.4
Defined Benefit Pension Items
Defined Benefit Plan Disclosure [Line Items]
Accumulated Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax	$ (1.6)	$ (0.9)	$ 0.7

BANK LINE OF CREDIT (Details)

BANK LINE OF CREDIT (Details) - USD ($) $ in Millions	Dec. 31, 2023	Jul. 27, 2016
Line of Credit Facility [Line Items]
Credit Agreement, maximum borrowing capacity		$ 75
Line of credit, amount outstanding	$ 0
Letter of Credit
Line of Credit Facility [Line Items]
Credit Agreement, maximum borrowing capacity		$ 20

Schedule II - Valuation and Q_2

Schedule II - Valuation and Qualifying Accounts (Details) - Allowance for Ship and Debit Credits - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	$ 53,184	$ 41,599	$ 26,435
Additions	202,159	241,817	311,443
Deductions	(219,326)	(230,232)	(296,279)
Balance at End of Period	$ 36,017	$ 53,184	$ 41,599

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Pay vs Performance Disclosure
Net Income (Loss)	$ 55,735	$ 170,851	$ 164,413

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Dec. 31, 2023
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false