MACOM Technology Solutions (MTSI) 10-Q 4 May 23 2023 Q2 Quarterly report Financial data

Cover Page

Cover Page - USD ($) $ in Thousands	6 Months Ended
	Mar. 31, 2023	May 01, 2023	Sep. 30, 2022
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2023
Document Transition Report	false
Entity File Number	001-35451
Entity Registrant Name	MACOM Technology Solutions Holdings, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	27-0306875
Entity Address, Address Line One	100 Chelmsford Street
Entity Address, City or Town	Lowell
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	01851
City Area Code	978
Local Phone Number	656-2500
Title of 12(b) Security	Common Stock, par value $0.001 per share
Trading Symbol	MTSI
Security Exchange Name	NASDAQ
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
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		70,884,080
Entity Central Index Key	0001493594
Amendment Flag	false
Current Fiscal Year End Date	--09-29
Document Fiscal Period Focus	Q2
Document Fiscal Year Focus	2023
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	$ (3,339)		$ (5,906)

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2023	Sep. 30, 2022
Assets, Current [Abstract]
Cash and cash equivalents	$ 136,573	$ 119,952
Short-term investments	440,735	466,580
Accounts Receivable, after Allowance for Credit Loss, Current	121,823	101,551
Inventories	131,882	114,960
Prepaid and other current assets	17,303	10,040
Total current assets	848,316	813,083
Property and equipment, net	123,266	123,701
Goodwill	324,610	311,417
Intangible assets, net	67,289	51,254
Deferred income taxes	217,816	237,415
Other long-term assets	36,176	34,947
Total assets	1,617,473	1,571,817
Current liabilities:
Finance lease liabilities	4,870	1,006
Accounts payable	31,095	30,733
Accrued liabilities	55,284	65,475
Total current liabilities	91,249	97,214
Finance lease liabilities	26,486	27,032
Financing obligation	9,436	9,544
Long-term debt	566,743	565,920
Other long-term liabilities	29,544	29,359
Total liabilities	723,458	729,069
Stockholders’ equity:
Common stock	71	70
Treasury stock, at cost	(330)	(330)
Accumulated other comprehensive income	(1,433)	(5,851)
Additional paid-in capital	1,194,719	1,203,145
Accumulated deficit	(299,012)	(354,286)
Total stockholders’ equity	894,015	842,748
Total liabilities and stockholders' equity	$ 1,617,473	$ 1,571,817

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2023	Apr. 01, 2022	Mar. 31, 2023	Apr. 01, 2022
Income Statement [Abstract]
Revenue	$ 169,406	$ 165,147	$ 349,510	$ 324,767
Cost of revenue	66,716	66,158	136,465	131,636
Gross profit	102,690	98,989	213,045	193,131
Operating expenses:
Research and development	35,537	35,455	74,369	70,925
Selling, general and administrative	31,249	30,963	64,189	62,566
Total operating expenses	66,786	66,418	138,558	133,491
Income from operations	35,904	32,571	74,487	59,640
Other income (expense):
Interest income (expense), net	1,634	(1,389)	2,236	(3,082)
Other (expense) income, net	(123)	(55)	(178)	114,853
Total other income (expense), net	1,511	(1,444)	2,058	111,771
Income before income taxes	37,415	31,127	76,545	171,411
Income tax expense	11,660	1,569	21,271	3,026
Net income	$ 25,755	$ 29,558	$ 55,274	$ 168,385
Net income per share:
Income (loss) per share - Basic (usd per share)	$ 0.36	$ 0.42	$ 0.78	$ 2.42
Income (loss) per share - Diluted (usd per share)	$ 0.36	$ 0.42	$ 0.77	$ 2.37
Weighted average shares used:
Basic (in shares)	70,799	69,788	70,640	69,594
Diluted (in shares)	71,402	71,107	71,388	71,166

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive (Loss) Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2023	Apr. 01, 2022	Mar. 31, 2023	Apr. 01, 2022
Statement of Comprehensive Income [Abstract]
Net income	$ 25,755	$ 29,558	$ 55,274	$ 168,385
OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), before Adjustment and Tax	833	(2,335)	3,380	(2,952)
Foreign currency translation gain (loss), net of tax	301	(679)	1,038	(1,003)
Other comprehensive income (loss), net of tax	1,134	(3,014)	4,418	(3,955)
Total comprehensive income	$ 26,889	$ 26,544	$ 59,692	$ 164,430

Condensed Consolidated Statem_3

Condensed Consolidated Statement of Stockholders' Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment	Common Stock	Treasury Stock	Accumulated Other Comprehensive Income	Additional Paid-in Capital	Additional Paid-in Capital Cumulative Effect, Period of Adoption, Adjustment	Accumulated Deficit	Accumulated Deficit Cumulative Effect, Period of Adoption, Adjustment
Balance at beginning of period, (in shares) at Oct. 01, 2021			68,877
Balance at beginning of period at Oct. 01, 2021	$ 471,736	$ (72,177)	$ 69	$ (330)	$ 4,150	$ 1,269,601	$ (79,690)	$ (801,754)	$ 7,513
Balance at beginning of period, treasury stock (in shares) at Oct. 01, 2021				(23)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock option exercises (in shares)			190
Stock option exercises	2,688					2,688
Vesting of restricted common stock and units (in shares)			1,284
Vesting of restricted common stock and units	1		$ 1
Issuance of common stock pursuant to employee stock purchase plan (in shares)			56
Issuance of common stock pursuant to employee stock purchase plan	2,447					2,447
Shares repurchased for stock withholdings on restricted stock awards (in shares)			(497)
Shares repurchased for tax withholdings on equity awards	(34,758)					(34,758)
Share-based compensation	19,916					19,916
Other comprehensive income, net of tax	(3,955)				(3,955)
Net income	168,385							168,385
Balance at end of period, (in shares) at Apr. 01, 2022			69,910
Balance at end of period at Apr. 01, 2022	554,283		$ 70	$ (330)	195	1,180,204		(625,856)
Balance at end of period, treasury stock (in shares) at Apr. 01, 2022				(23)
Balance at beginning of period, (in shares) at Dec. 31, 2021			69,709
Balance at beginning of period at Dec. 31, 2021	524,774		$ 70	$ (330)	3,209	1,177,239		(655,414)
Balance at beginning of period, treasury stock (in shares) at Dec. 31, 2021				(23)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Vesting of restricted common stock and units (in shares)			315
Vesting of restricted common stock and units	0		$ 0
Shares repurchased for stock withholdings on restricted stock awards (in shares)			(114)
Shares repurchased for tax withholdings on equity awards	(7,002)					(7,002)
Share-based compensation	9,967					9,967
Other comprehensive income, net of tax	(3,014)				(3,014)
Net income	29,558							29,558
Balance at end of period, (in shares) at Apr. 01, 2022			69,910
Balance at end of period at Apr. 01, 2022	554,283		$ 70	$ (330)	195	1,180,204		(625,856)
Balance at end of period, treasury stock (in shares) at Apr. 01, 2022				(23)
Balance at beginning of period, (in shares) at Sep. 30, 2022			70,022
Balance at beginning of period at Sep. 30, 2022	842,748		$ 70	$ (330)	(5,851)	1,203,145		(354,286)
Balance at beginning of period, treasury stock (in shares) at Sep. 30, 2022				(23)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Vesting of restricted common stock and units (in shares)			1,338
Vesting of restricted common stock and units	1		$ 1
Issuance of common stock pursuant to employee stock purchase plan (in shares)			52
Issuance of common stock pursuant to employee stock purchase plan	2,320					2,320
Shares repurchased for stock withholdings on restricted stock awards (in shares)			(515)
Shares repurchased for tax withholdings on equity awards	(31,253)					(31,253)
Share-based compensation	20,507					20,507
Other comprehensive income, net of tax	4,418				4,418
Net income	55,274							55,274
Balance at end of period, (in shares) at Mar. 31, 2023			70,897
Balance at end of period at Mar. 31, 2023	894,015		$ 71	$ (330)	(1,433)	1,194,719		(299,012)
Balance at end of period, treasury stock (in shares) at Mar. 31, 2023				(23)
Balance at beginning of period, (in shares) at Dec. 30, 2022			70,757
Balance at beginning of period at Dec. 30, 2022	862,544		$ 71	$ (330)	(2,567)	1,190,137		(324,767)
Balance at beginning of period, treasury stock (in shares) at Dec. 30, 2022				(23)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Vesting of restricted common stock and units (in shares)			212
Vesting of restricted common stock and units	0		$ 0
Shares repurchased for stock withholdings on restricted stock awards (in shares)			(72)
Shares repurchased for tax withholdings on equity awards	(4,878)					(4,878)
Share-based compensation	9,460					9,460
Other comprehensive income, net of tax	1,134				1,134
Net income	25,755							25,755
Balance at end of period, (in shares) at Mar. 31, 2023			70,897
Balance at end of period at Mar. 31, 2023	$ 894,015		$ 71	$ (330)	$ (1,433)	$ 1,194,719		$ (299,012)
Balance at end of period, treasury stock (in shares) at Mar. 31, 2023				(23)

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Mar. 31, 2023	Apr. 01, 2022
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 55,274	$ 168,385
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and intangibles amortization	25,365	29,080
Share-based compensation	20,507	19,916
Deferred income taxes	20,233	1,284
Gain on equity method investment, net	0	(114,908)
Other adjustments, net	(2,784)	1,176
Change in operating assets and liabilities:
Accounts receivable	(18,316)	(15,983)
Inventories	(8,236)	(10,653)
Prepaid expenses and other assets	(2,857)	597
Accounts payable	(253)	1,632
Accrued and other liabilities	(17,471)	(4,930)
Income taxes	(715)	1,001
Net cash provided by operating activities	70,747	76,597
CASH FLOWS FROM INVESTING ACTIVITIES:
Acquisition of business, net of cash acquired	(50,835)	0
Proceeds from sale of equity method investment	0	127,750
Purchases of property and equipment	(15,614)	(12,184)
Proceeds from sales and maturities of short-term investments	261,634	91,841
Purchases of short-term investments	(228,157)	(282,642)
Proceeds from sale of property and equipment	8,000	23
Net cash used in investing activities	(24,972)	(75,212)
CASH FLOWS FROM FINANCING ACTIVITIES:
Payments on finance leases and other	(591)	(500)
Proceeds from stock option exercises and employee stock purchases	2,320	5,135
Repurchase of common stock - tax withholdings on equity awards	(31,253)	(34,758)
Net cash used in financing activities	(29,524)	(30,123)
Foreign currency effect on cash	370	(224)
NET CHANGE IN CASH AND CASH EQUIVALENTS	16,621	(28,962)
CASH AND CASH EQUIVALENTS — Beginning of period	119,952	156,537
CASH AND CASH EQUIVALENTS — End of period	$ 136,573	$ 127,575

Supplemental Cash Flow Informat

Supplemental Cash Flow Information	6 Months Ended
	Mar. 31, 2023
Supplemental Cash Flow Elements [Abstract]
Supplemental Cash Flow Information	SUPPLEMENTAL CASH FLOW INFORMATION The following is a summary of supplemental cash flow information for the periods presented (in thousands): Six Months Ended March 31, April 1, Cash paid for interest $ 5,367 $ 2,953 Cash paid for income taxes $ 1,701 $ 695 Non-cash activities: Operating lease right-of-use assets obtained in exchange for new lease liabilities $ 3,920 $ 2,306 Finance lease assets obtained in exchange for new lease liabilities $ 3,821 $ — Additions to property and equipment, net included in liabilities $ — $ 2,010 During the six months ended April 1, 2022, we capitalized $0.9 million of non-cash costs to property and equipment associated with construction of a power generator that were paid by our service provider and included in Additions to property and equipment, net included in liabilities above. See Note 10 - Financing Obligation .

Supplemental Cash Flow Inform_2

Supplemental Cash Flow Information	6 Months Ended
	Mar. 31, 2023
Supplemental Cash Flow Elements [Abstract]
Schedule of Supplemental Cash Flow Information Regarding Non-cash Investing and Financing Activities	The following is a summary of supplemental cash flow information for the periods presented (in thousands): Six Months Ended March 31, April 1, Cash paid for interest $ 5,367 $ 2,953 Cash paid for income taxes $ 1,701 $ 695 Non-cash activities: Operating lease right-of-use assets obtained in exchange for new lease liabilities $ 3,920 $ 2,306 Finance lease assets obtained in exchange for new lease liabilities $ 3,821 $ — Additions to property and equipment, net included in liabilities $ — $ 2,010

Supplemental Cash Flow Inform_3

Supplemental Cash Flow Information - Additional Information $ in Millions	Apr. 01, 2022 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Capitalized Costs, Uncompleted Wells, Equipment and Facilities	$ 0.9

Supplemental Cash Flow Inform_4

Supplemental Cash Flow Information - Schedule of Supplemental Cash Flow Information Regarding Non-cash Investing and Financing Activities - USD ($) $ in Thousands	6 Months Ended
	Mar. 31, 2023	Apr. 01, 2022
Supplemental Cash Flow Elements [Abstract]
Cash paid for interest	$ 5,367	$ 2,953
Cash paid for income taxes	1,701	695
Operating lease right-of-use assets obtained in exchange for new lease liabilities	3,920	2,306
Financing lease assets obtained in exchange for new lease liabilities	3,821	0
Additions to property and equipment, net included in liabilities	$ 0	$ 2,010

Summary of Significant Accounti

Summary of Significant Accounting Policies	6 Months Ended
	Mar. 31, 2023
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Unaudited Interim Financial Information —The accompanying unaudited, condensed consolidated financial statements have been prepared according to the rules and regulations of the United States (the “U.S.”) Securities and Exchange Commission (the “SEC”) and, in the opinion of management, reflect all adjustments, which include normal recurring adjustments, necessary for a fair statement of the condensed consolidated balance sheets, condensed consolidated statements of operations, comprehensive income, stockholders' equity and cash flows of MACOM Technology Solutions Holdings, Inc. (“MACOM”, the “Company”, “us”, “we” or “our”) for the periods presented. We prepare our interim financial information using the same accounting principles we use for our annual audited consolidated financial statements. Certain information and note disclosures normally included in the annual audited consolidated financial statements have been condensed or omitted in accordance with prescribed SEC rules. We believe that the disclosures made in our condensed consolidated financial statements and the accompanying notes are adequate to make the information presented not misleading. The condensed consolidated balance sheet as of September 30, 2022 is as reported in our audited consolidated financial statements as of that date. Our accounting policies are described in the notes to our September 30, 2022 consolidated financial statements, which were included in our Annual Report on Form 10-K for our fiscal year ended September 30, 2022 filed with the SEC on November 14, 2022 (the “2022 Annual Report on Form 10-K”). We recommend that the financial statements included in this Quarterly Report on Form 10-Q be read in conjunction with the consolidated financial statements and notes included in our 2022 Annual Report on Form 10-K. Principles of Consolidation, Basis of Presentation and Reclassification —The accompanying condensed consolidated financial statements include our accounts and the accounts of our majority-owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. In the condensed consolidated financial statements, certain balances have been reclassified to conform to the current year presentation. We have a 52- or 53-week fiscal year ending on the Friday closest to the last day of September. Fiscal years 2023 and 2022 each include 52 weeks. To offset the effect of holidays, for fiscal years in which there are 53 weeks, we include the extra week arising in such fiscal years in the first fiscal quarter. Use of Estimates —The preparation of condensed consolidated 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 during the reporting periods, the reported amounts of revenue and expenses during the reporting periods and the disclosure of contingent assets and liabilities at the date of the financial statements. On an ongoing basis, we base estimates and assumptions on historical experience, currently available information and various other factors that management believes to be reasonable under the circumstances. Actual results may differ materially from these estimates and assumptions. The accounting policies which our management believes involve the most significant application of judgment or involve complex estimation, are inventories and associated reserves; revenue reserves; goodwill and intangible asset valuation; share-based compensation valuations and income taxes. Recent Accounting Pronouncements —Our Recent Accounting Pronouncements are described in our 2022 Annual Report on Form 10-K. Pronouncements for Adoption in Subsequent Periods The FASB issued ASU 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting , amended by ASU 2022-06, Reference Rate Reform (Topic 848): Deferral of the Sunset Date of Topic 848 , which provides optional expedients and exceptions to applying the guidance on contract modifications, hedge accounting, and other transactions, to simplify the accounting for transitioning from the London Interbank Offered Rate, and other interbank offered rates expected to be discontinued, to alternative reference rates. The guidance in this update was effective upon its issuance. If elected, the guidance is to be applied prospectively through December 31, 2024. We are currently evaluating the effect the potential adoption of this ASU will have on our consolidated financial statements, including, but not limited to, our Credit Agreement (defined below). For additional information regarding our Credit Agreement, refer to Note 9 - Debt.

Revenue

Revenue	6 Months Ended
	Mar. 31, 2023
Revenue [Abstract]
Revenue	REVENUE Disaggregation of Revenue We disaggregate revenue from contracts with customers by markets and geography, as we believe it best depicts how the nature, amount, timing and uncertainty of revenue and cash flows are affected by economic factors. The following tables present our revenue disaggregated by markets and geography (in thousands): Three Months Ended Six Months Ended March 31, 2023 April 1, 2022 March 31, 2023 April 1, 2022 Revenue by Market: Telecommunications $ 53,888 $ 62,927 $ 115,337 $ 118,749 Industrial & Defense 77,194 67,139 154,363 140,285 Data Center 38,324 35,081 79,810 65,733 Total $ 169,406 $ 165,147 $ 349,510 $ 324,767 Three Months Ended Six Months Ended March 31, 2023 April 1, 2022 March 31, 2023 April 1, 2022 Revenue by Geographic Region: United States $ 82,835 $ 74,547 $ 171,423 $ 148,973 China 33,325 46,028 74,481 82,091 Asia Pacific, excluding China (1) 28,008 25,881 49,542 56,531 Other Countries (2) 25,238 18,691 54,064 37,172 Total $ 169,406 $ 165,147 $ 349,510 $ 324,767 (1) Asia Pacific primarily represents Australia, Japan, Malaysia, Singapore, South Korea, Taiwan and Thailand. (2) No country or region represented greater than 10% of our total revenue as of the dates presented, other than the United States, China and Asia Pacific region as presented above. Contract Balances We record contract assets or contract liabilities depending on the timing of revenue recognition, billings and cash collections on a contract-by-contract basis. Our contract liabilities primarily relate to deferred revenue, including advanced consideration received from customers for contracts prior to the transfer of control to the customer, and therefore revenue is subsequently recognized upon delivery of products and services. The following table presents the changes in contract liabilities during the six months ended March 31, 2023 (in thousands, except percentage): March 31, 2023 September 30, 2022 $ Change % Change Contract liabilities $ 1,076 $ 3,916 $ (2,840) (73) %

Acquisitions

Acquisitions	6 Months Ended
	Mar. 31, 2023
Business Combination and Asset Acquisition [Abstract]
Acquisitions	ACQUISITIONS Acquisition of Linearizer Technology Inc.— On March 3, 2023, we completed the acquisition of Linearizer Technology, Inc. (“Linearizer”), a developer of modules and subsystems, including solid state amplifiers (SSPAs), microwave predistortion linearizers and microwave photonics (the “Linearizer Acquisition”). We acquired Linearizer to further strengthen our component and subsystem design expertise in our target markets. In connection with the Linearizer Acquisition, we acquired all of the outstanding shares of Linearizer for total cash consideration of approximately $51.6 million, subject to customary purchase price adjustments. We funded the Linearizer Acquisition with cash-on-hand. During the three and six months ended March 31, 2023, we incurred acquisition-related transaction costs of approximately $1.9 million, which are included in selling, general and administrative expense. There were no transaction costs for the three and six months ended April 1, 2022. The Linearizer Acquisition was accounted for as a business combination and the operations of Linearizer have been included in our consolidated financial statements since the date of acquisition. The purchase price for the Linearizer Acquisition has been allocated based on preliminary estimates of fair values of the acquired assets and assumed liabilities at the date of acquisition as follows (in thousands): At Acquisition Date as Reported Current assets $ 11,726 Property and equipment 5,485 Intangible assets 29,600 Goodwill 12,332 Total assets acquired 59,143 Current liabilities 7,544 Total liabilities assumed 7,544 Purchase Price $ 51,599 We recorded goodwill of $12.3 million. Intangible assets consist of customer relationships of $20.7 million with an 8.6 year life, technology of $7.1 million with a 7.6 year life and a trade name of $1.8 million with a 7.6 year life. We used the income approach to determine the fair value of the definite-lived intangible assets and the cost and market approaches to determine the fair value of our property, plant and equipment. We amortize definite-lived assets based on the pattern over which we expect to receive the economic benefit from these assets. The intangible assets and goodwill acquired will be amortizable for tax purposes due to the Section 338 election filed. The determination and allocation of purchase price consideration is based on preliminary estimates of fair value; such estimates and assumptions are subject to change within the measurement period (up to one year from the acquisition date). As of March 31, 2023, the purchase price allocation for Linearizer remains open as we gather additional information regarding the assets acquired and the liabilities assumed, primarily in relation to the valuation of intangibles, inventory, fixed assets, leases and contingencies. Pro forma financial information for the three and six months ended March 31, 2023 and April 1, 2022 and the actual results of operations for Linearizer since the acquisition date are not material to our condensed consolidated financial statements for the periods presented. On March 3, 2023, we entered into a lease agreement with an entity that is majority-owned by certain former Linearizer employees, which is deemed to be a related party agreement. We have the option to purchase the facility for $3.8 million. As of the date of this Quarterly Report on Form 10-Q, we have not exercised such right. During the three months ended March 31, 2023, we made lease-related payments of $0.2 million. This lease is classified as a finance lease on our condensed consolidated balance sheet and is included in property and equipment of $5.5 million in the purchase price allocation table above. Other Acquisition — On December 23, 2022, we entered into a definitive agreement to acquire substantially all of the assets and certain specified liabilities of OMMIC SAS, a semiconductor manufacturer based in France with expertise in wafer fabrication, epitaxial growth and monolithic microwave integrated circuit semiconductor processing and integrated circuit design. The purchase price is expected to be approximately €38.5 million, funded by cash-on-hand, and the proposed transaction is expected to close in our fiscal year 2023 , subject to regulatory and other government approvals and the satisfaction of certain closing conditions.

Investments

Investments	6 Months Ended
	Mar. 31, 2023
Investments, Debt and Equity Securities [Abstract]
Investments	INVESTMENTS All investments are short-term in nature and are invested in corporate bonds and commercial paper and are classified as available-for-sale. These corporate bonds and commercial paper are owned directly by the Company and are segregated in brokerage custody accounts. The amortized cost, gross unrealized holding gains or losses and fair value of our available-for-sale investments by major investment type are summarized in the tables below (in thousands): March 31, 2023 Amortized Gross Gross Aggregate Fair Corporate bonds $ 140,151 $ 27 $ (2,999) $ 137,179 Commercial paper 303,871 25 (340) 303,556 Total short-term investments $ 444,022 $ 52 $ (3,339) $ 440,735 September 30, 2022 Amortized Gross Gross Aggregate Fair Corporate bonds $ 146,163 $ 5 $ (4,492) $ 141,676 Commercial paper 326,318 — (1,414) 324,904 Total short-term investments $ 472,481 $ 5 $ (5,906) $ 466,580 The contractual maturities of available-for-sale investments were as follows (in thousands): March 31, 2023 September 30, 2022 Less than one year $ 347,944 $ 368,141 Over one year 92,791 98,439 Total available-for-sale investments $ 440,735 $ 466,580 We have determined that the gross unrealized losses on available for sale securities as of March 31, 2023 and September 30, 2022 are temporary in nature and/or do not relate to credit loss, and therefore there is no expense for credit losses recorded in our condensed consolidated statements of operations. Unrealized gains and losses on available-for-sale investments are reported as a separate component of stockholders’ equity within accumulated other comprehensive income. During the three months ended March 31, 2023 and April 1, 2022, Interest income (expense), net included interest income on short-term investments of $5.1 million and $0.5 million, respectively. During the six months ended March 31, 2023 and April 1, 2022, Interest income (expense), net included interest income on short-term investments of $8.7 million and $0.8 million, respectively. Other Investments — As of March 31, 2023, we held a non-marketable equity investment in Series B preferred stock of a privately held manufacturing corporation with preferred liquidation rights over other equity shares. As the equity securities do not have a readily determinable fair value and do not qualify for the practical expedient under Accounting Standards Codification 820, Fair Value Measurement, we have elected to account for this investment at cost less any impairment. We evaluate this investment for impairment at each balance sheet date. As of March 31, 2023 and September 30, 2022, the carrying value of this investment was $2.5 million and it was classified as a long-term investment. On December 23, 2021, we sold our non-controlling investment of less than 10% in the outstanding equity of a private company to one of the other limited liability company members, pursuant to the terms of a previously negotiated call option included in the private company’s limited liability company agreement, as amended and restated (the “LLC Agreement”), in exchange for a predetermined fixed price as set forth in the LLC Agreement of approximately $127.8 million in cash consideration. As of December 23, 2021, the carrying value of this investment was approximately $9.5 million. As a result of this transaction, during the three months ended December 31, 2021, we recorded a gain of $118.2 million in Other (expense) income, net in our condensed consolidated statements of operations. The six months ended April 1, 2022 includes a gain on the sale of our equity method investment of $118.2 million, and we recorded net losses of $3.3 million associated with such equity method investment.

Fair Value

Fair Value	6 Months Ended
	Mar. 31, 2023
Fair Value Disclosures [Abstract]
Fair Value	FAIR VALUE We group our financial assets and liabilities measured at fair value on a recurring basis in three levels, based on the markets in which the assets and liabilities are traded, and the reliability of the assumptions used to determine fair value. These levels are: Level 1 - Quoted prices in active markets for identical assets or liabilities. Level 2 - Observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities, quoted prices in markets with insufficient volume or infrequent transactions (less active markets), or model-driven valuations in which all significant inputs are observable or can be derived principally from, or corroborated with, observable market data. Level 3 - Fair value is derived from valuation techniques in which one or more significant inputs are unobservable, including assumptions and judgments made by us. Assets and Liabilities Measured and Recorded at Fair Value on a Recurring Basis We measure certain assets and liabilities at fair value on a recurring basis such as our financial instruments. There have been no transfers between Level 1, 2 or 3 assets or liabilities during the three and six months ended March 31, 2023. Assets and liabilities measured at fair value on a recurring basis consist of the following (in thousands): March 31, 2023 Fair Value Active Markets for Identical Assets (Level 1) Observable Inputs (Level 2) Unobservable Inputs (Level 3) Assets Money market funds $ 20,570 $ 20,570 $ — $ — Commercial paper 303,556 — 303,556 — Corporate bonds 137,179 — 137,179 — Total assets measured at fair value $ 461,305 $ 20,570 $ 440,735 $ — September 30, 2022 Fair Value Active Markets for Identical Assets (Level 1) Observable Inputs (Level 2) Unobservable Inputs (Level 3) Assets Money market funds $ 1,392 $ 1,392 $ — $ — Commercial paper 324,904 — 324,904 — Corporate bonds 141,676 — 141,676 — Total assets measured at fair value $ 467,972 $ 1,392 $ 466,580 $ —

Inventories

Inventories	6 Months Ended
	Mar. 31, 2023
Inventory Disclosure [Abstract]
Inventories	INVENTORIES Inventories consist of the following (in thousands): March 31, September 30, Raw materials $ 83,057 $ 72,595 Work-in-process 16,990 12,455 Finished goods 31,835 29,910 Total inventory, net $ 131,882 $ 114,960

Property, Plant and Equipment

Property, Plant and Equipment	6 Months Ended
	Mar. 31, 2023
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	PROPERTY AND EQUIPMENT Property and equipment consists of the following (in thousands): March 31, September 30, Construction in process $ 14,318 $ 10,837 Machinery and equipment 229,125 227,844 Leasehold improvements 35,288 35,651 Furniture and fixtures 2,601 2,535 Computer equipment and software 18,519 18,347 Finance lease assets 38,238 34,417 Total property and equipment 338,089 329,631 Less accumulated depreciation and amortization (214,823) (205,930) Property and equipment, net $ 123,266 $ 123,701 Depreciation and amortization expense related to property and equipment for the three and six months ended March 31, 2023 was $5.8 million and $11.8 million, respectively. Depreciation and amortization expense related to property and equipment for the three and six months ended April 1, 2022 was $5.8 million and $11.7 million, respectively. Accumulated amortization on finance lease assets as of March 31, 2023 and September 30, 2022 was $6.7 million and $5.8 million, respectively.

Intangible Assets

Intangible Assets	6 Months Ended
	Mar. 31, 2023
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets	INTANGIBLE ASSETS Amortization expense related to intangible assets is as follows (in thousands): Three Months Ended Six Months Ended March 31, April 1, March 31, April 1, Cost of revenue $ 988 $ 1,778 $ 1,898 $ 4,283 Selling, general and administrative 5,764 6,276 11,667 13,058 Total $ 6,752 $ 8,054 $ 13,565 $ 17,341 Intangible assets consist of the following (in thousands): March 31, September 30, Acquired technology $ 186,534 $ 179,434 Customer relationships 266,570 245,870 Trade name 5,200 3,400 Total 458,304 428,704 Less accumulated amortization (391,015) (377,450) Intangible assets — net $ 67,289 $ 51,254 A summary of the activity in gross intangible assets and goodwill is as follows (in thousands): Intangible Assets Total Intangible Assets Acquired Customer Trade Name Goodwill Balance as of September 30, 2022 $ 428,704 $ 179,434 $ 245,870 $ 3,400 $ 311,417 Acquired 29,600 7,100 20,700 1,800 12,332 Currency translation adjustment — — — — 861 Balance as of March 31, 2023 $ 458,304 $ 186,534 $ 266,570 $ 5,200 $ 324,610 As of March 31, 2023, our estimated amortization of our intangible assets in future fiscal years was as follows (in thousands): 2023 Remaining 2024 2025 2026 2027 Thereafter Total Amortization expense $ 14,295 18,643 7,381 6,397 5,842 11,331 $ 63,889 Accumulated amortization for acquired technology and customer relationships were $177.1 million and $213.9 million, respectively, as of March 31, 2023, and $175.2 million and $202.3 million, respectively, as of September 30, 2022.

Debt

Debt	6 Months Ended
	Mar. 31, 2023
Debt Disclosure [Abstract]
Debt	DEBT The following represents the outstanding balances and effective interest rates of our borrowings as of March 31, 2023 and September 30, 2022, (in thousands, except percentages): March 31, 2023 September 30, 2022 Principal Balance Effective Interest Rate Principal Balance Effective Interest Rate LIBOR plus 2.25% term loans due May 2024 $ 120,766 6.88 % $ 120,766 4.77 % 0.25% convertible notes due March 2026 450,000 0.54 % 450,000 0.54 % Total principal amount outstanding 570,766 570,766 Less: Unamortized discount on term loans and deferred financing costs (4,023) (4,846) Total long-term debt $ 566,743 $ 565,920 Term Loans As of March 31, 2023, we are party to a credit agreement, dated as of May 8, 2014, with a syndicate of lenders and Goldman Sachs Bank USA, as administrative agent (as amended on February 13, 2015, August 31, 2016, March 10, 2017, May 19, 2017, May 2, 2018 and May 9, 2018, the “Credit Agreement”). As of March 31, 2023, the Credit Agreement consisted of term loans with an initial aggregate principal amount of $700.0 million (the “Term Loans”) that will mature in May 2024 and bear interest at: (i) for LIBOR loans for any interest period, a rate per annum equal to the LIBOR rate as determined by the administrative agent, plus an applicable margin of 2.25%; and (ii) for base rate loans, a rate per annum equal to the greater of (a) the prime rate quoted in the print edition of the Wall Street Journal, Money Rates Section, (b) the federal funds rate plus one-half of 1.00% and (c) the LIBOR rate applicable to a one-month interest period plus 1.00% (but, in each case, not less than 1.00%), plus an applicable margin of 1.25%. The UK Financial Conduct Authority announced that they will cease publishing certain tenors of USD LIBOR on June 30, 2023; we expect our interest rate to change to synthetic USD LIBOR during the third quarter of fiscal year 2023. As of March 31, 2023, there are no minimum principal repayments on the Term Loans until May 2024 when the remaining principal balance of $120.8 million becomes due. The fair value of the Term Loans was estimated to be approximately $120.3 million and $120.2 million as of March 31, 2023 and September 30, 2022, respectively, and was determined using Level 2 inputs, including a quoted price from a financial institution. As of March 31, 2023, approximately $0.4 million of deferred financing costs remain unamortized related to the Term Loans and is recorded as a direct reduction of the recognized debt liabilities in our accompanying condensed consolidated balance sheet. The Term Loans are secured by a first priority lien on substantially all of our assets and provide that we must comply with certain financial and non-financial covenants. 2026 Convertible Notes On March 25, 2021, we issued 0.25% convertible senior notes due in fiscal year 2026, pursuant to an indenture dated as of such date (the “Indenture”), between the Company and U.S. Bank National Association, as trustee, with an aggregate principal amount of $400.0 million (the “Initial Notes”), and on April 6, 2021, we issued an additional $50.0 million aggregate principal amount (the “Additional Notes”) (together, the “2026 Convertible Notes”). The aggregate principal balance of the 2026 Convertible Notes is $450.0 million. The 2026 Convertible Notes will mature on March 15, 2026, unless earlier converted, redeemed or repurchased. The Additional Notes were issued and sold to the initial purchaser of the Initial Notes, pursuant to the option to purchase the Additional Notes granted by the Company to the initial purchaser and have the same terms as the Initial Notes. Holders of the 2026 Convertible Notes may convert their notes at their option at any time prior to the close of business on the business day immediately preceding December 15, 2025 in multiples of $1,000 principal amount, only under the following circumstances: (i) during any fiscal quarter commencing after the fiscal quarter ending on July 2, 2021 (and only during such fiscal quarter), if the last reported sale price of our common stock for at least 20 trading days (whether or not consecutive) during a period of 30 consecutive trading days ending on the last trading day of the immediately preceding fiscal quarter is greater than or equal to 130% of the conversion price for the notes on each applicable trading day; (ii) during the five business day period after any five consecutive trading day period (the “Measurement Period”) in which the “trading price” (as defined in the Indenture) per $1,000 principal amount of the notes for each trading day of the Measurement Period was less than 98% of the product of the last reported sale price of our common stock and the conversion rate for the notes on each such trading day; (iii) if we call such notes for redemption, at any time prior to the close of business on the second scheduled trading day immediately preceding the applicable redemption date; or (iv) upon the occurrence of specified corporate events described in the Indenture. On or after December 15, 2025 until the close of business on the second scheduled trading day immediately preceding the maturity date, holders may convert their notes in multiples of $1,000 principal amount, regardless of the foregoing circumstances. The initial conversion rate for the 2026 Convertible Notes is 12.1767 shares of common stock per $1,000 principal amount of the notes, equivalent to an initial conversion price of approximately $82.12 per share of common stock. The conversion rate will be subject to adjustment upon the occurrence of certain specified events in the Indenture. In November 2021, we made an irrevocable election to pay cash for the aggregate principal amount of notes to be converted. Upon conversion of the 2026 Convertible Notes, we are required to pay cash up to the aggregate principal amount of the notes to be converted and pay or deliver, as the case may be, cash, shares of our common stock or a combination of cash and shares of our common stock, at our election, in respect of the remainder, if any, of our conversion obligation in excess of the aggregate principal amount of the notes being converted (subject to, and in accordance with, the settlement provisions of the Indenture). We may not redeem the notes prior to March 20, 2024. We may redeem for cash all or any portion of the notes, at our option, on or after March 20, 2024 if the last reported sale price per share of our common stock has been at least 130% of the conversion price then in effect for at least 20 trading days (whether or not consecutive), including the trading day immediately preceding the date on which we provide notice of redemption, during any 30 consecutive trading day period ending on, and including, the trading day immediately preceding the date on which we provide notice of redemption, at a redemption price equal to 100% of the principal amount of the notes to be redeemed, plus accrued and unpaid interest, to, but not including, the redemption date. The Indenture does not contain any financial or operating covenants or restrictions on the payments of dividends, the making of investments, the incurrence of indebtedness or the purchase or prepayment of securities by us or any of our subsidiaries. In connection with the adoption of ASU 2020-06, Debt—Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging—Contracts in Entity’s Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity, on October 2, 2021 we reclassified $72.2 million, consisting of $73.1 million of principal and issuance costs of $0.9 million, previously allocated to the conversion feature, from additional paid-in capital to long-term debt on our condensed consolidated balance sheet as of October 2, 2021. The reclassification was recorded to combine the two legacy units of account into a single instrument classified as a liability. We also recognized a cumulative effect adjustment of $7.5 million to accumulated deficit on our condensed consolidated balance sheet as of October 2, 2021, that was primarily driven by the derecognition of interest expense related to the accretion of the Debt Discount as required under the legacy accounting guidance. Under ASU 2020-06, we will no longer incur non-cash interest expense related to the accretion of the debt discount associated with the embedded conversion option. For the three and six months ended March 31, 2023, total interest expense for the 2026 Convertible Notes was $0.3 million and $0.6 million, respectively. For the three and six months ended April 1, 2022, total interest expense for the 2026 Convertible Notes was $0.3 million and $0.6 million, respectively. The fair value of our 2026 Convertible Notes, including the conversion feature, was $472.5 million and $411.4 million as of March 31, 2023 and September 30, 2022, respectively, and was determined based on quoted prices in markets that are not active, which is considered a Level 2 valuation input. There are no future minimum principal payments under the notes as of March 31, 2023; the full amount of $450.0 million is due in fiscal year 2026.

Financing Obligation

Financing Obligation	6 Months Ended
	Mar. 31, 2023
Debt Disclosure [Abstract]
Financing Obligation	FINANCING OBLIGATION We are party to a power purchase agreement for the use of electric power and thermal energy producing systems at our fabrication facility in Lowell, Massachusetts. T hese systems are expected to reduce our consumption of energy while delivering sustainable, resilient energy for heating and cooling. We do not own these systems; however, we control the use of the assets during operation. As of March 31, 2023 and September 30, 2022 , the net book value of the systems in Property and equipment, net was $9.2 million and $9.8 million, respectively, and the corresponding liability was $9.7 million and $9.8 million, respectively, primarily classified in Financing obligation on our condensed consolidated balance sheet. The financing obligation was calculated based on future fixed payments allocated to the power generator of $16.8 million over the 15-year term, discounted at an implied discount rate of 7.4%, and the remaining future minimum payments are for power purchases. In total, we have $27.2 million in fixed payments associated with the power purchase agreement, which has a 15-year term. As of March 31, 2023, expected future minimum payments for the financing obligation were as follows (in thousands): Fiscal year ending: Amount 2023 $ 468 2024 958 2025 982 2026 1,007 2027 1,031 Thereafter 11,914 Total payments $ 16,360 Less: interest 6,688 Present value of liabilities $ 9,672

Earnings (Loss) Per Share

Earnings (Loss) Per Share	6 Months Ended
	Mar. 31, 2023
Earnings Per Share [Abstract]
Earnings (Loss) Per Share	EARNINGS PER SHARE The following table sets forth the computation for basic and diluted net income per share of common stock (in thousands, except per share data): Three Months Ended Six Months Ended March 31, 2023 April 1, 2022 March 31, 2023 April 1, 2022 Numerator: Net income attributable to common stockholders $ 25,755 $ 29,558 $ 55,274 $ 168,385 Denominator: Weighted average common shares outstanding-basic 70,799 69,788 70,640 69,594 Dilutive effect of stock options, restricted stock and restricted stock units 603 1,319 748 1,572 Weighted average common shares outstanding-diluted 71,402 71,107 71,388 71,166 Net income to common stockholders per share-Basic: $ 0.36 $ 0.42 $ 0.78 $ 2.42 Net income to common stockholders per share-Diluted: $ 0.36 $ 0.42 $ 0.77 $ 2.37

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Mar. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIESFrom time to time, we may be subject to commercial disputes, employment issues, claims by other companies in the industry that we have infringed their intellectual property rights and other similar claims and litigation. Any such claims may lead to future litigation and material damages and defense costs. We were not involved in any material pending legal proceedings during the three and six months ended March 31, 2023.

Share-Based Compensation

Share-Based Compensation	6 Months Ended
	Mar. 31, 2023
Share-Based Payment Arrangement [Abstract]
Share-Based Compensation	SHARE-BASED COMPENSATION We have authorized 10 million shares of $0.001 par value preferred stock and 300 million shares of $0.001 par value common stock as of March 31, 2023. Stock Plans As of March 31, 2023, we had 4.6 million shares available for issuance under our 2021 Omnibus Incentive Plan (the “2021 Plan”), which replaced our 2012 Omnibus Incentive Plan (as amended and restated) (the “2012 Plan”), and 1.3 million shares available for issuance under our 2021 Employee Stock Purchase Plan (the “Employee Stock Purchase Plan”), which replaced our 2012 Employee Stock Purchase Plan. We have outstanding awards under the 2021 Plan and the 2012 Plan. Following the adoption of the 2021 Plan, no additional awards have been or will be made under the 2012 Plan. Under the 2021 Plan, we have the ability to issue incentive stock options (“ISOs”), non-statutory stock options (“NSOs”), stock appreciation rights (“SARs”), restricted stock awards (“RSAs”), unrestricted stock awards, stock units (including restricted stock units (“RSUs”) and performance-based restricted stock units (“PRSUs”)), performance awards, cash awards, and other share-based awards to employees, directors, consultants and advisors. The ISOs and NSOs must be granted at an exercise price, and the SARs must be granted at a base value, per share of not less than 100% of the closing price of a share of our common stock on the date of grant (or, if no closing price is reported on that date, the closing price on the immediately preceding date on which a closing price was reported) (110% in the case of certain ISOs). Options granted under the 2012 Plan primarily vested based on certain market-based and performance-based criteria and generally have a term of four years to seven years. Certain of the share-based awards granted and outstanding as of March 31, 2023 are subject to accelerated vesting upon a change in control of the Company. Incentive Stock Units Aside from the equity plans described above, we also grant incentive stock units (“ISUs”) to certain of our international employees which typically vest over three As of March 31, 2023 and September 30, 2022, the fair value of outstanding ISUs was $4.5 million and $4.9 million, respectively, and the associated accrued compensation liability was $2.1 million and $3.6 million, respectively. During the three and six months ended March 31, 2023, we recorded an expense for ISU awards of $0.5 million and $1.8 million, respectively. During the three and six months ended April 1, 2022, we recorded a benefit for ISU awards of $0.9 million and expense of $0.6 million, respectively. These expenses are not included in the share-based compensation expense totals below. Share-Based Compensation The following table shows a summary of share-based compensation expense included in the condensed consolidated statements of operations (in thousands): Three Months Ended Six Months Ended March 31, April 1, March 31, April 1, Cost of revenue $ 1,011 $ 1,073 $ 2,161 $ 2,106 Research and development 3,742 3,511 7,974 7,110 Selling, general and administrative 4,707 5,383 10,372 10,700 Total share-based compensation expense $ 9,460 $ 9,967 $ 20,507 $ 19,916 As of March 31, 2023, the total unrecognized compensation costs related to RSAs, RSUs and PRSUs was $70.4 million, which we expect to recognize over a weighted-average period of 2.1 years. As of March 31, 2023, total unrecognized compensation cost related to our Employee Stock Purchase Plan was $0.3 million. Restricted Stock, Restricted Stock Units and Performance-Based Restricted Stock Unit Awards A summary of stock award activity for the six months ended March 31, 2023 is as follows: Number of shares Weighted- Balance as of September 30, 2022 1,872 $ 40.44 Granted 751 63.25 Performance-based adjustment (1) 311 27.13 Vested and released (1,338) 28.11 Forfeited, canceled or expired (39) 47.46 Balance as of March 31, 2023 1,557 $ 59.23 (1) The amount shown represents performance adjustments for performance-based awards. These were granted in prior fiscal years and vested during the six months ended March 31, 2023 based on the Company’s achievement of adjusted earnings per share performance conditions. Stock awards that vested during the six months ended March 31, 2023 and April 1, 2022 had combined fair values of $81.3 million and $89.3 million, respectively, as of the vesting date. RSUs granted generally vest over a period of three We granted 166,452 market-based PRSUs during the six months ended March 31, 2023, at a weighted average grant date fair value of $80.38 per share, and none were forfeited. Recipients may earn between 0% and 200% of the target number of shares based on the Company’s achievement of total stockholder return in comparison to a peer group of companies in the PHLX Semiconductor Sector Index (^SOX) over a period of approximately 3 years. The fair value of the awards was estimated using a Monte Carlo simulation and compensation expense is recognized ratably over the service period based on the grant date fair value of the awards subject to the market condition. The expected volatility of the Company’s common stock was estimated based on the historical average volatility rate over the three-year period. The dividend yield assumption was based on historical and anticipated dividend payouts. The risk-free rate assumption was based on observed interest rates consistent with the three-year measurement period. The assumptions used to value the awards are as follows: Six Months Ended March 31, Grant date stock price $ 56.15 Average stock price at the start of the performance period $ 54.12 Risk free interest rate 4.2% Years to maturity 2.90 Expected volatility rate 52.4% Expected dividend yield — Stock Options As of March 31, 2023 and December 30, 2022, there were 15,000 stock options outstanding with a weighted-average exercise price per share of $16.06. As of March 31, 2023, the weighted-average remaining contractual term was 2.60 years and the aggregate intrinsic value was $0.8 million. Aggregate intrinsic value is calculated using the difference between our closing stock price on March 31, 2023 and the exercise price of outstanding, in-the-money options. The total intrinsic value of options exercised was $11.0 million for the six months ended April 1, 2022. There were no options exercised during the three and six months ended March 31, 2023 and three months ended April 1, 2022, respectively.

Income Taxes

Income Taxes	6 Months Ended
	Mar. 31, 2023
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES We are subject to income tax in the U.S. as well as other tax jurisdictions in which we conduct business. Earnings from non-U.S. activities are subject to local country income tax and may also be subject to current U.S. income tax. For interim periods, we record a tax provision or benefit based upon the estimated effective tax rate expected for the full fiscal year, adjusted for material discrete taxation matters arising during the interim periods. Our quarterly tax provision or benefit, and its quarterly estimate of the annual effective tax rate, are subject to significant variation due to several factors. These factors include items such as: variability in accurately predicting pre-tax income/loss, the mix of jurisdictions in which we operate, intercompany transactions, changes in how we do business, tax law developments, the realizability of our deferred tax assets and related valuation allowance and relative changes in permanent tax benefits or expenses. The provision for income taxes and effective income tax rate are as follows (in thousands, except percentages): Three Months Ended Six Months Ended March 31, April 1, March 31, April 1, Income tax expense $ 11,660 $ 1,569 $ 21,271 $ 3,026 Effective income tax rate 31.2 % 5.0 % 27.8 % 1.8 % The difference between the U.S. federal statutory income tax rate of 21% and our effective income tax rate for the three and six months ended March 31, 2023 was primarily driven by tax on global intangible low-taxed income (“GILTI”) including changes to Section 174, non-deductible compensation and state income taxes partially offset by income taxed in foreign jurisdictions generally at lower tax rates and research and development (“R&D”) tax credits. The difference between the U.S. federal statutory income tax rate of 21% and our effective income tax rate for the three and six months ended April 1, 2022 was primarily driven by the full valuation allowance against any expense associated with income in the U.S. and income taxed in foreign jurisdictions generally at lower tax rates, where a valuation allowance does not apply. On September 30, 2022, we released the majority of the valuation allowances against U.S. federal and state deferred tax assets including operating loss (“NOL”) carryforwards, R&D tax credit carryforwards and other deferred tax items relating to temporary differences. We continued our ongoing assessment of the realizability of our deferred tax assets and did not note any significant changes from our assessment on September 30, 2022. We continue to maintain a partial valuation allowance against certain of our deferred tax assets primarily relating to state NOLs and R&D tax credit carryforwards which are not expected to be realized. We recognize deferred tax assets to the extent that we believe that these assets are more likely than not to be realized. In making this determination, we consider available positive and negative evidence. We look at factors that may impact the valuation of our deferred tax assets including results of recent operations, future reversals of existing taxable temporary differences, projected future taxable income and tax-planning strategies. There were no unrecognized tax benefits as of March 31, 2023 and September 30, 2022. It is our policy to recognize any interest and penalties accrued related to unrecognized tax benefits in income tax expense. During the fiscal quarter ended March 31, 2023, we did not make any accrual or payment of interest or penalties.

Geographic and Significant Cust

Geographic and Significant Customer Information	6 Months Ended
	Mar. 31, 2023
Segment Reporting [Abstract]
Geographic and Significant Customer Information	GEOGRAPHIC AND SIGNIFICANT CUSTOMER INFORMATION We have one reportable operating segment that designs, develops, manufactures and markets semiconductors and modules. The determination of the number of reportable operating segments is based on the chief operating decision maker’s (“CODM”) use of financial information provided for the purposes of assessing performance and making operating decisions. The Company's CODM is its President and Chief Executive Officer. In evaluating financial performance and making operating decisions, the CODM primarily uses consolidated metrics. The Company assesses its determination of operating segments at least annually. We continue to evaluate our internal reporting structure and the potential impact of any changes on our segment reporting. For information about our revenue in different geographic regions, based upon customer locations, see Note 2 - Revenue . Information about net property and equipment in different geographic regions is presented below (in thousands): March 31, September 30, United States $ 117,606 $ 108,569 Other Countries (1) 5,660 15,132 Total $ 123,266 $ 123,701 (1) Other than the United States, no country represented greater than 10% of the total net property and equipment as of the dates presented. No customer represented more than 10% of revenue or m ore than 10% of accounts receivable in the periods presented in the accompanying condensed consolidated financial statements.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Mar. 31, 2023
Accounting Policies [Abstract]
Principles of Consolidation	Principles of Consolidation, Basis of Presentation and Reclassification—The accompanying condensed consolidated financial statements include our accounts and the accounts of our majority-owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. In the condensed consolidated financial statements, certain balances have been reclassified to conform to the current year presentation.
Fiscal Period	We have a 52- or 53-week fiscal year ending on the Friday closest to the last day of September. Fiscal years 2023 and 2022 each include 52 weeks. To offset the effect of holidays, for fiscal years in which there are 53 weeks, we include the extra week arising in such fiscal years in the first fiscal quarter.
Use of Estimates	Use of Estimates—The preparation of condensed consolidated 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 during the reporting periods, the reported amounts of revenue and expenses during the reporting periods and the disclosure of contingent assets and liabilities at the date of the financial statements. On an ongoing basis, we base estimates and assumptions on historical experience, currently available information and various other factors that management believes to be reasonable under the circumstances. Actual results may differ materially from these estimates and assumptions. The accounting policies which our management believes involve the most significant application of judgment or involve complex estimation, are inventories and associated reserves; revenue reserves; goodwill and intangible asset valuation; share-based compensation valuations and income taxes.
Recent Accounting Pronouncements	Recent Accounting Pronouncements —Our Recent Accounting Pronouncements are described in our 2022 Annual Report on Form 10-K. Pronouncements for Adoption in Subsequent Periods The FASB issued ASU 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting , amended by ASU 2022-06, Reference Rate Reform (Topic 848): Deferral of the Sunset Date of Topic 848 , which provides optional expedients and exceptions to applying the guidance on contract modifications, hedge accounting, and other transactions, to simplify the accounting for transitioning from the London Interbank Offered Rate, and other interbank offered rates expected to be discontinued, to alternative reference rates. The guidance in this update was effective upon its issuance. If elected, the guidance is to be applied prospectively through December 31, 2024. We are currently evaluating the effect the potential adoption of this ASU will have on our consolidated financial statements, including, but not limited to, our Credit Agreement (defined below). For additional information regarding our Credit Agreement, refer to Note 9 - Debt.

Revenue (Tables)

Revenue (Tables)	6 Months Ended
	Mar. 31, 2023
Revenue [Abstract]
Disaggregation of Revenue	The following tables present our revenue disaggregated by markets and geography (in thousands): Three Months Ended Six Months Ended March 31, 2023 April 1, 2022 March 31, 2023 April 1, 2022 Revenue by Market: Telecommunications $ 53,888 $ 62,927 $ 115,337 $ 118,749 Industrial & Defense 77,194 67,139 154,363 140,285 Data Center 38,324 35,081 79,810 65,733 Total $ 169,406 $ 165,147 $ 349,510 $ 324,767 Three Months Ended Six Months Ended March 31, 2023 April 1, 2022 March 31, 2023 April 1, 2022 Revenue by Geographic Region: United States $ 82,835 $ 74,547 $ 171,423 $ 148,973 China 33,325 46,028 74,481 82,091 Asia Pacific, excluding China (1) 28,008 25,881 49,542 56,531 Other Countries (2) 25,238 18,691 54,064 37,172 Total $ 169,406 $ 165,147 $ 349,510 $ 324,767 (1) Asia Pacific primarily represents Australia, Japan, Malaysia, Singapore, South Korea, Taiwan and Thailand. (2) No country or region represented greater than 10% of our total revenue as of the dates presented, other than the United States, China and Asia Pacific region as presented above.
Contract with Customer, Asset and Liability	The following table presents the changes in contract liabilities during the six months ended March 31, 2023 (in thousands, except percentage): March 31, 2023 September 30, 2022 $ Change % Change Contract liabilities $ 1,076 $ 3,916 $ (2,840) (73) %

Acquisitions (Tables)

Acquisitions (Tables)	6 Months Ended
	Mar. 31, 2023
Business Combination and Asset Acquisition [Abstract]
Schedule of Business Acquisitions, by Acquisition	The purchase price for the Linearizer Acquisition has been allocated based on preliminary estimates of fair values of the acquired assets and assumed liabilities at the date of acquisition as follows (in thousands): At Acquisition Date as Reported Current assets $ 11,726 Property and equipment 5,485 Intangible assets 29,600 Goodwill 12,332 Total assets acquired 59,143 Current liabilities 7,544 Total liabilities assumed 7,544 Purchase Price $ 51,599

Investments (Tables)

Investments (Tables)	6 Months Ended
	Mar. 31, 2023
Investments, Debt and Equity Securities [Abstract]
Summary of Contractual Maturities of Investments	The contractual maturities of available-for-sale investments were as follows (in thousands): March 31, 2023 September 30, 2022 Less than one year $ 347,944 $ 368,141 Over one year 92,791 98,439 Total available-for-sale investments $ 440,735 $ 466,580
Debt Securities, Available-for-sale	The amortized cost, gross unrealized holding gains or losses and fair value of our available-for-sale investments by major investment type are summarized in the tables below (in thousands): March 31, 2023 Amortized Gross Gross Aggregate Fair Corporate bonds $ 140,151 $ 27 $ (2,999) $ 137,179 Commercial paper 303,871 25 (340) 303,556 Total short-term investments $ 444,022 $ 52 $ (3,339) $ 440,735 September 30, 2022 Amortized Gross Gross Aggregate Fair Corporate bonds $ 146,163 $ 5 $ (4,492) $ 141,676 Commercial paper 326,318 — (1,414) 324,904 Total short-term investments $ 472,481 $ 5 $ (5,906) $ 466,580

Fair Value (Tables)

Fair Value (Tables)	6 Months Ended
	Mar. 31, 2023
Fair Value Disclosures [Abstract]
Assets and Liabilities Measured at Fair Value on Recurring Basis	Assets and liabilities measured at fair value on a recurring basis consist of the following (in thousands): March 31, 2023 Fair Value Active Markets for Identical Assets (Level 1) Observable Inputs (Level 2) Unobservable Inputs (Level 3) Assets Money market funds $ 20,570 $ 20,570 $ — $ — Commercial paper 303,556 — 303,556 — Corporate bonds 137,179 — 137,179 — Total assets measured at fair value $ 461,305 $ 20,570 $ 440,735 $ — September 30, 2022 Fair Value Active Markets for Identical Assets (Level 1) Observable Inputs (Level 2) Unobservable Inputs (Level 3) Assets Money market funds $ 1,392 $ 1,392 $ — $ — Commercial paper 324,904 — 324,904 — Corporate bonds 141,676 — 141,676 — Total assets measured at fair value $ 467,972 $ 1,392 $ 466,580 $ —

Inventories (Tables)

Inventories (Tables)	6 Months Ended
	Mar. 31, 2023
Inventory Disclosure [Abstract]
Components of Inventories	Inventories consist of the following (in thousands): March 31, September 30, Raw materials $ 83,057 $ 72,595 Work-in-process 16,990 12,455 Finished goods 31,835 29,910 Total inventory, net $ 131,882 $ 114,960

Property, Plant and Equipment (

Property, Plant and Equipment (Tables)	6 Months Ended
	Mar. 31, 2023
Property, Plant and Equipment [Abstract]
Components of Property, Plant and Equipment	Property and equipment consists of the following (in thousands): March 31, September 30, Construction in process $ 14,318 $ 10,837 Machinery and equipment 229,125 227,844 Leasehold improvements 35,288 35,651 Furniture and fixtures 2,601 2,535 Computer equipment and software 18,519 18,347 Finance lease assets 38,238 34,417 Total property and equipment 338,089 329,631 Less accumulated depreciation and amortization (214,823) (205,930) Property and equipment, net $ 123,266 $ 123,701

Intangible Assets (Tables)

Intangible Assets (Tables)	6 Months Ended
	Mar. 31, 2023
Goodwill and Intangible Assets Disclosure [Abstract]
Summary of Amortization Expense of Intangible Assets	Amortization expense related to intangible assets is as follows (in thousands): Three Months Ended Six Months Ended March 31, April 1, March 31, April 1, Cost of revenue $ 988 $ 1,778 $ 1,898 $ 4,283 Selling, general and administrative 5,764 6,276 11,667 13,058 Total $ 6,752 $ 8,054 $ 13,565 $ 17,341
Summary of Intangible Assets	Intangible assets consist of the following (in thousands): March 31, September 30, Acquired technology $ 186,534 $ 179,434 Customer relationships 266,570 245,870 Trade name 5,200 3,400 Total 458,304 428,704 Less accumulated amortization (391,015) (377,450) Intangible assets — net $ 67,289 $ 51,254
Summary of Activity in Intangible Assets and Goodwill	A summary of the activity in gross intangible assets and goodwill is as follows (in thousands): Intangible Assets Total Intangible Assets Acquired Customer Trade Name Goodwill Balance as of September 30, 2022 $ 428,704 $ 179,434 $ 245,870 $ 3,400 $ 311,417 Acquired 29,600 7,100 20,700 1,800 12,332 Currency translation adjustment — — — — 861 Balance as of March 31, 2023 $ 458,304 $ 186,534 $ 266,570 $ 5,200 $ 324,610
Summary of Estimated Amortization of Intangible Assets in Future Fiscal Years	As of March 31, 2023, our estimated amortization of our intangible assets in future fiscal years was as follows (in thousands): 2023 Remaining 2024 2025 2026 2027 Thereafter Total Amortization expense $ 14,295 18,643 7,381 6,397 5,842 11,331 $ 63,889

Debt (Tables)

Debt (Tables)	6 Months Ended
	Mar. 31, 2023
Debt Disclosure [Abstract]
Schedule of Remained Outstanding on Term Loans	The following represents the outstanding balances and effective interest rates of our borrowings as of March 31, 2023 and September 30, 2022, (in thousands, except percentages): March 31, 2023 September 30, 2022 Principal Balance Effective Interest Rate Principal Balance Effective Interest Rate LIBOR plus 2.25% term loans due May 2024 $ 120,766 6.88 % $ 120,766 4.77 % 0.25% convertible notes due March 2026 450,000 0.54 % 450,000 0.54 % Total principal amount outstanding 570,766 570,766 Less: Unamortized discount on term loans and deferred financing costs (4,023) (4,846) Total long-term debt $ 566,743 $ 565,920

Financing Obligations (Tables)

Financing Obligations (Tables)	6 Months Ended
	Mar. 31, 2023
Debt Disclosure [Abstract]
Financing Obligation, Liability, Fiscal Year Maturity	As of March 31, 2023, expected future minimum payments for the financing obligation were as follows (in thousands): Fiscal year ending: Amount 2023 $ 468 2024 958 2025 982 2026 1,007 2027 1,031 Thereafter 11,914 Total payments $ 16,360 Less: interest 6,688 Present value of liabilities $ 9,672

Earnings (Loss) Per Share (Tabl

Earnings (Loss) Per Share (Tables)	6 Months Ended
	Mar. 31, 2023
Earnings Per Share [Abstract]
Computation for Basic and Diluted Net Loss Per Share of Common Stock	The following table sets forth the computation for basic and diluted net income per share of common stock (in thousands, except per share data): Three Months Ended Six Months Ended March 31, 2023 April 1, 2022 March 31, 2023 April 1, 2022 Numerator: Net income attributable to common stockholders $ 25,755 $ 29,558 $ 55,274 $ 168,385 Denominator: Weighted average common shares outstanding-basic 70,799 69,788 70,640 69,594 Dilutive effect of stock options, restricted stock and restricted stock units 603 1,319 748 1,572 Weighted average common shares outstanding-diluted 71,402 71,107 71,388 71,166 Net income to common stockholders per share-Basic: $ 0.36 $ 0.42 $ 0.78 $ 2.42 Net income to common stockholders per share-Diluted: $ 0.36 $ 0.42 $ 0.77 $ 2.37

Share-Based Compensation (Table

Share-Based Compensation (Tables)	6 Months Ended
	Mar. 31, 2023
Share-Based Payment Arrangement [Abstract]
Effects of Stock-Based Compensation Expense Related to Stock-Based Awards to Employees and Nonemployees	The following table shows a summary of share-based compensation expense included in the condensed consolidated statements of operations (in thousands): Three Months Ended Six Months Ended March 31, April 1, March 31, April 1, Cost of revenue $ 1,011 $ 1,073 $ 2,161 $ 2,106 Research and development 3,742 3,511 7,974 7,110 Selling, general and administrative 4,707 5,383 10,372 10,700 Total share-based compensation expense $ 9,460 $ 9,967 $ 20,507 $ 19,916
Summary of Restricted Stock, Restricted Stock Unit and Performance-based Restricted Stock Unit Activity	A summary of stock award activity for the six months ended March 31, 2023 is as follows: Number of shares Weighted- Balance as of September 30, 2022 1,872 $ 40.44 Granted 751 63.25 Performance-based adjustment (1) 311 27.13 Vested and released (1,338) 28.11 Forfeited, canceled or expired (39) 47.46 Balance as of March 31, 2023 1,557 $ 59.23 (1) The amount shown represents performance adjustments for performance-based awards. These were granted in prior fiscal years and vested during the six months ended March 31, 2023 based on the Company’s achievement of adjusted earnings per share performance conditions.
Schedule of Share-Based Payment Award, Market Based Restricted Stock Awards, Valuation Assumptions	The assumptions used to value the awards are as follows: Six Months Ended March 31, Grant date stock price $ 56.15 Average stock price at the start of the performance period $ 54.12 Risk free interest rate 4.2% Years to maturity 2.90 Expected volatility rate 52.4% Expected dividend yield —

Income Taxes (Tables)

Income Taxes (Tables)	6 Months Ended
	Mar. 31, 2023
Income Tax Disclosure [Abstract]
Schedule of Provision for Income Taxes and Effective Income Tax Rate	The provision for income taxes and effective income tax rate are as follows (in thousands, except percentages): Three Months Ended Six Months Ended March 31, April 1, March 31, April 1, Income tax expense $ 11,660 $ 1,569 $ 21,271 $ 3,026 Effective income tax rate 31.2 % 5.0 % 27.8 % 1.8 %

Geographic and Significant Cu_2

Geographic and Significant Customer Information (Tables)	6 Months Ended
	Mar. 31, 2023
Segment Reporting [Abstract]
Long-lived Assets by Geographic Areas	Information about net property and equipment in different geographic regions is presented below (in thousands): March 31, September 30, United States $ 117,606 $ 108,569 Other Countries (1) 5,660 15,132 Total $ 123,266 $ 123,701 (1) Other than the United States, no country represented greater than 10% of the total net property and equipment as of the dates presented.
Schedule of Revenue by Major Customers by Reporting Segments

Revenue (Details)

Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2023	Apr. 01, 2022	Mar. 31, 2023	Apr. 01, 2022	Sep. 30, 2022
Disaggregation of Revenue [Line Items]
Revenue	$ 169,406	$ 165,147	$ 349,510	$ 324,767
Contract liabilities	1,076		1,076		$ 3,916
Increase (decrease) in contract with customer liability			(2,840)
Amounts included in contract liabilities at the beginning of the period	1,400		$ 2,900
Net change in contract liabilities (percentage)			(73.00%)
Industrial & Defense
Disaggregation of Revenue [Line Items]
Revenue	77,194	67,139
Data Center
Disaggregation of Revenue [Line Items]
Revenue	38,324	35,081
Telecom
Disaggregation of Revenue [Line Items]
Revenue	53,888	62,927
United States
Disaggregation of Revenue [Line Items]
Revenue	82,835	74,547	$ 171,423	148,973
China
Disaggregation of Revenue [Line Items]
Revenue	33,325	46,028	74,481	82,091
Asia Pacific, excluding China
Disaggregation of Revenue [Line Items]
Revenue	28,008	25,881	49,542	56,531
Other Countries
Disaggregation of Revenue [Line Items]
Revenue	$ 25,238	$ 18,691	54,064	37,172
Industrial & Defense
Disaggregation of Revenue [Line Items]
Revenue			154,363	140,285
Data Center
Disaggregation of Revenue [Line Items]
Revenue			79,810	65,733
Telecom
Disaggregation of Revenue [Line Items]
Revenue			$ 115,337	$ 118,749

Acquisitions - Narrative (Detai

Acquisitions - Narrative (Details) $ in Thousands, € in Millions				3 Months Ended	6 Months Ended
	Mar. 31, 2023 USD ($)	Mar. 03, 2023 USD ($)	Dec. 23, 2022 EUR (€)	Mar. 31, 2023 USD ($)	Mar. 31, 2023 USD ($)	Apr. 01, 2022 USD ($)
Business Acquisition [Line Items]
Financing cash flows from finance leases					$ 591	$ 500
OMMIC SAS
Business Acquisition [Line Items]
Expected purchase price of acquisition | €			€ 38.5
Customer relationships
Business Acquisition [Line Items]
Intangible assets	$ 20,700			$ 20,700	20,700
Useful life of intangible assets (in years)	8 years 7 months 6 days
Technology
Business Acquisition [Line Items]
Intangible assets	$ 7,100			7,100	7,100
Useful life of intangible assets (in years)	7 years 7 months 6 days
Trade Names
Business Acquisition [Line Items]
Intangible assets	$ 1,800			1,800	1,800
Useful life of intangible assets (in years)	7 years 7 months 6 days
Linearizer Technology, Inc.
Business Acquisition [Line Items]
Cash consideration		$ 51,600
Transaction costs				1,900	1,900
Intangible assets	$ 29,600			29,600	$ 29,600
Option to purchase underlying asset		$ 3,800
Financing cash flows from finance leases				$ 200

Acquisitions - Summary of Purch

Acquisitions - Summary of Purchase Price For Acquisition, Allocations (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Sep. 30, 2022
Business Acquisition [Line Items]
Goodwill	$ 324,610	$ 311,417
Linearizer Technology, Inc.
Business Acquisition [Line Items]
Current assets	11,726
Property and equipment	5,485
Intangible assets	29,600
Goodwill	12,332
Total assets acquired	59,143
Current liabilities	7,544
Total liabilities assumed	7,544
Purchase Price	$ 51,599

Investments - Summary of Availa

Investments - Summary of Available for Sale Investments (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2023	Apr. 01, 2022	Mar. 31, 2023	Apr. 01, 2022	Sep. 30, 2022
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 444,022		$ 444,022		$ 472,481
Gross Unrealized Holding Gains	52		52		5
Gross Unrealized Holding Losses	3,339		3,339		5,906
Aggregate Fair Value	440,735		440,735		466,580
Investment Income, Interest	5,100	$ 500	8,700	$ 800
Corporate bonds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	140,151		140,151		146,163
Gross Unrealized Holding Gains	27		27		5
Gross Unrealized Holding Losses	2,999		2,999		4,492
Aggregate Fair Value	137,179		137,179		141,676
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	303,871		303,871		326,318
Gross Unrealized Holding Gains	25		25		0
Gross Unrealized Holding Losses	340		340		1,414
Aggregate Fair Value	$ 303,556		$ 303,556		$ 324,904

Investments - Summary of Contra

Investments - Summary of Contractual Maturities of Investments (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Sep. 30, 2022
Investments, Debt and Equity Securities [Abstract]
Less than one year	$ 347,944	$ 368,141
Over one year	92,791	98,439
Total available-for-sale investments	$ 440,735	$ 466,580

Investments - Other Investments

Investments - Other Investments (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2023	Apr. 01, 2022	Mar. 31, 2023	Apr. 01, 2022	Sep. 30, 2022	Dec. 23, 2021
Equity Securities without Readily Determinable Fair Value [Line Items]
Loss on equity method investment			$ 0	$ 114,908
Proceeds from sale of equity method investment			0	$ 127,750
Preferred Stock | Privately Held Manufacturing Company
Equity Securities without Readily Determinable Fair Value [Line Items]
Investment without readily determinable fair value	$ 2,500		$ 2,500		$ 2,500
Equity Securities | Private Company
Equity Securities without Readily Determinable Fair Value [Line Items]
Carrying value of investment						$ 9,500
Gain on sale of investment	$ 118,200
Equity Securities | Compute
Equity Securities without Readily Determinable Fair Value [Line Items]
Loss on equity method investment		$ 3,300
Private Company | Equity Securities
Equity Securities without Readily Determinable Fair Value [Line Items]
Noncontrolling interest ownership percentage		10%		10%

Fair Value - Assets and Liabili

Fair Value - Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Mar. 31, 2023	Sep. 30, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	$ 461,305	$ 467,972
Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	137,179	141,676
Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	20,570	1,392
Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	303,556	324,904
Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	20,570	1,392
Active Markets for Identical Assets (Level 1) | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	0	0
Active Markets for Identical Assets (Level 1) | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	20,570	1,392
Active Markets for Identical Assets (Level 1) | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	0	0
Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	440,735	466,580
Observable Inputs (Level 2) | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	137,179	141,676
Observable Inputs (Level 2) | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	0	0
Observable Inputs (Level 2) | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	303,556	324,904
Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	0	0
Unobservable Inputs (Level 3) | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	0	0
Unobservable Inputs (Level 3) | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	0	0
Unobservable Inputs (Level 3) | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	$ 0	$ 0

Inventories (Details)

Inventories (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Sep. 30, 2022
Inventory Disclosure [Abstract]
Raw materials	$ 83,057	$ 72,595
Work-in-process	16,990	12,455
Finished goods	31,835	29,910
Total inventory, net	$ 131,882	$ 114,960

Property Plant and Equipment -

Property Plant and Equipment - Components of Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Sep. 30, 2022
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 338,089	$ 329,631
Less accumulated depreciation and amortization	(214,823)	(205,930)
Property and equipment, net	123,266	123,701
Finance Lease, Right-of-Use Asset, Accumulated Amortization	6,700	5,800
Construction in process
Property, Plant and Equipment [Line Items]
Total property and equipment	14,318	10,837
Machinery and equipment
Property, Plant and Equipment [Line Items]
Total property and equipment	229,125	227,844
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total property and equipment	35,288	35,651
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Total property and equipment	2,601	2,535
Computer equipment and software
Property, Plant and Equipment [Line Items]
Total property and equipment	18,519	18,347
Assets Held Under Finance Leases [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 38,238	$ 34,417

Property Plant and Equipment _2

Property Plant and Equipment - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2023	Apr. 01, 2022	Mar. 31, 2023	Apr. 01, 2022	Sep. 30, 2022
Property, Plant and Equipment [Abstract]
Depreciation and amortization expense	$ 5,800	$ 5,800	$ 11,800	$ 11,700
Accumulated depreciation	$ 214,823		$ 214,823		$ 205,930

Intangible Assets - Summary of

Intangible Assets - Summary of Amortization Expense of Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2023	Apr. 01, 2022	Mar. 31, 2023	Apr. 01, 2022
Finite-Lived Intangible Assets [Line Items]
Total	$ 6,752	$ 8,054	$ 13,565	$ 17,341
Cost of Revenue
Finite-Lived Intangible Assets [Line Items]
Total	988	1,778	1,898	4,283
Selling, General and Administrative
Finite-Lived Intangible Assets [Line Items]
Total	$ 5,764	$ 6,276	$ 11,667	$ 13,058

Intangible Assets - Summary o_2

Intangible Assets - Summary of Intangible Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Sep. 30, 2022
Finite-Lived Intangible Assets [Line Items]
Total	$ 458,304	$ 428,704
Total	458,304	428,704
Less accumulated amortization	(391,015)	(377,450)
Intangible assets — net	67,289	51,254
Developed technology
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets	186,534	179,434
Less accumulated amortization	(177,100)	(175,200)
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets	266,570	245,870
Less accumulated amortization	(213,900)	(202,300)
Trade Names | Trade Names
Finite-Lived Intangible Assets [Line Items]
Total	5,200	3,400
Total	$ 5,200	$ 3,400

Intangible Assets - Summary o_3

Intangible Assets - Summary of Activity in Intangible Assets and Goodwill (Details) $ in Thousands	6 Months Ended
	Mar. 31, 2023 USD ($)
Goodwill and Intangible Assets [Roll Forward]
Beginning Balance	$ 428,704
Acquired	29,600
Currency translation adjustment	0
Ending Balance	458,304
Finite-lived Intangible Assets [Roll Forward]
Acquired	29,600
Indefinite Lived Intangible Assets Rollforward [Roll Forward]
Beginning Balance	428,704
Acquired	29,600
Currency translation adjustment	0
Ending Balance	458,304
Goodwill [Roll Forward]
Balance at beginning of period	311,417
Acquired	12,332
Currency translation adjustment	861
Balance at end of period	324,610
Developed technology
Goodwill and Intangible Assets [Roll Forward]
Acquired	7,100
Finite-lived Intangible Assets [Roll Forward]
Beginning Balance	179,434
Acquired	7,100
Currency translation adjustment	0
Ending Balance	186,534
Indefinite Lived Intangible Assets Rollforward [Roll Forward]
Acquired	7,100
Customer relationships
Goodwill and Intangible Assets [Roll Forward]
Acquired	20,700
Finite-lived Intangible Assets [Roll Forward]
Beginning Balance	245,870
Acquired	20,700
Currency translation adjustment	0
Ending Balance	266,570
Indefinite Lived Intangible Assets Rollforward [Roll Forward]
Acquired	20,700
Trade Names | Trade Names
Goodwill and Intangible Assets [Roll Forward]
Beginning Balance	3,400
Acquired	1,800
Currency translation adjustment	0
Ending Balance	5,200
Finite-lived Intangible Assets [Roll Forward]
Acquired	1,800
Indefinite Lived Intangible Assets Rollforward [Roll Forward]
Beginning Balance	3,400
Acquired	1,800
Currency translation adjustment	0
Ending Balance	$ 5,200

Intangible Assets - Summary o_4

Intangible Assets - Summary of Estimated Amortization of Intangible Assets (Details) $ in Thousands	Mar. 31, 2023 USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
2023 Remaining	$ 14,295
2022	18,643
2023	7,381
2024	6,397
2025	5,842
Thereafter	11,331
Total	$ 63,889

Intangible Assets - Additional

Intangible Assets - Additional Information (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Sep. 30, 2022
Finite-Lived Intangible Assets [Line Items]
Accumulated amortization	$ 391,015	$ 377,450
Developed technology
Finite-Lived Intangible Assets [Line Items]
Accumulated amortization	177,100	175,200
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Accumulated amortization	$ 213,900	$ 202,300

Debt - Schedule of Remaining Ou

Debt - Schedule of Remaining Outstanding Balances on Term Loans (Details) - USD ($) $ in Thousands	6 Months Ended
	Mar. 31, 2023	Sep. 30, 2022
Principal Balance
Long-term debt	$ 570,766	$ 570,766
Long-term debt	$ 566,743	565,920
Long-term Debt
Debt Instrument [Line Items]
Basis spread on variable rate	2.25%
Principal Balance
Long-term debt	$ 120,766	120,766
Less: Unamortized discount on term loans and deferred financing costs	$ (4,023)	$ (4,846)
Effective Interest Rate
Effective interest rate	6.88%	4.77%
Convertible Debt
Principal Balance
Long-term debt	$ 450,000	$ 450,000
Effective Interest Rate
Effective interest rate	0.54%	0.54%

Debt - Additional Information (

Debt - Additional Information (Details) $ / shares in Units, $ in Thousands			3 Months Ended		6 Months Ended
	Oct. 02, 2021 USD ($)	Mar. 25, 2021 USD ($) d renewal_option $ / shares	Mar. 31, 2023 USD ($)	Apr. 01, 2022 USD ($)	Mar. 31, 2023 USD ($)	Apr. 01, 2022 USD ($)	Sep. 30, 2022 USD ($)	Apr. 06, 2021 USD ($)
Debt Instrument [Line Items]
Long-term debt, remaining balance			$ 570,766		$ 570,766		$ 570,766
Accumulated deficit			(299,012)		(299,012)		(354,286)
Accumulated Deficit | Cumulative Effect, Period of Adoption, Adjustment
Debt Instrument [Line Items]
Accumulated deficit	$ 7,500
Long-term Debt
Debt Instrument [Line Items]
Principle amount			700,000		$ 700,000
Basis spread on variable rate					2.25%
Long-term debt, remaining balance			120,766		$ 120,766		120,766
Estimated fair value of Term Loans			120,300		120,300		120,200
Unamortized deferred financing costs			400		400
Convertible Notes Green Shoe
Debt Instrument [Line Items]
Principle amount								$ 50,000
Convertible Debt
Debt Instrument [Line Items]
Long-term debt, remaining balance			450,000		450,000		450,000
Convertible Senior Notes Due 2026
Debt Instrument [Line Items]
Principle amount		$ 400,000	450,000		450,000
Conversion price (in USD per share) | $ / shares		$ 82,120,000
Redemption price percentage		100%
Equity component of convertible notes, net	72,200
Interest expense debt			300	$ 300	600	$ 600
Future minimum principal payments			0		0
Convertible Senior Notes Due 2026 | Cumulative Effect, Period of Adoption, Adjustment
Debt Instrument [Line Items]
Principle amount	73,100
Convertible Senior Notes Due 2026 | Conversion Period One
Debt Instrument [Line Items]
Convertible threshold trading days | renewal_option		20,000,000
Threshold consecutive trading days | renewal_option		30,000,000
Convertible Senior Notes Due 2026 | Conversion Period Two
Debt Instrument [Line Items]
Convertible threshold trading days | d		5
Threshold consecutive trading days | d		5
Convertible Senior Notes Due 2026 | Conversion Price | Conversion Period One
Debt Instrument [Line Items]
Convertible threshold percentage of stock price trigger		130%
Convertible Senior Notes Due 2026 | Principal Trading Price | Conversion Period Two
Debt Instrument [Line Items]
Convertible threshold percentage of stock price trigger		98%
Convertible Senior Notes Due 2026 | Convertible Notes Payable
Debt Instrument [Line Items]
Basis spread on variable rate		0.25%
Estimated fair value of Term Loans			$ 472,500		$ 472,500		$ 411,400
Convertible Senior Notes Due 2026 | Convertible Debt
Debt Instrument [Line Items]
Conversion ratio					0.0121767
Convertible Senior Notes Due 2026 | Convertible Debt | Cumulative Effect, Period of Adoption, Adjustment
Debt Instrument [Line Items]
Unamortized deferred financing costs	$ 900
Fed Funds Effective Rate Overnight Index Swap Rate | Term Loans
Debt Instrument [Line Items]
Basis spread on variable rate					0.50%
One Month London Interbank Offered Rate (LIBOR) | Long-term Debt
Debt Instrument [Line Items]
Basis spread on variable rate					1%
Minimum | Base Rate | Long-term Debt
Debt Instrument [Line Items]
Basis spread on variable rate					1.25%

Financing Obligation (Details)

Financing Obligation (Details) - USD ($) $ in Thousands	6 Months Ended
	Mar. 31, 2023	Sep. 30, 2022
Long-term Purchase Commitment [Line Items]
Property and equipment, net capitalized	$ 9,200	$ 9,800
Financing obligation for property, plant and equipment	9,700	$ 9,800
Future fixed payment	$ 16,800
Power generator life term	15 years
Implied discount rate	7.40%
2023	$ 468
Purchase Commitment
Long-term Purchase Commitment [Line Items]
Fixed payments	$ 27,200

Financing Obligations - Summary

Financing Obligations - Summary of Expected Future Minimum Payments (Details) $ in Thousands	Mar. 31, 2023 USD ($)
Debt Disclosure [Abstract]
2023	$ 468
2024	958
2025	982
2026	1,007
2027	1,031
Thereafter	11,914
Total payments	16,360
Less: interest	6,688
Present value of liabilities	$ 9,672

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Details)	Mar. 31, 2023 $ / shares shares
Equity [Abstract]
Preferred stock, shares authorized | shares	10,000,000
Preferred stock, par value (in usd per share) | $ / shares	$ 0.001
Common stock, shares authorized | shares	300,000,000
Common stock, par value (in usd per share) | $ / shares	$ 0.001

Earnings (Loss) Per Share (Deta

Earnings (Loss) Per Share (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2023	Apr. 01, 2022	Mar. 31, 2023	Apr. 01, 2022
Numerator:
Net income	$ 25,755	$ 29,558	$ 55,274	$ 168,385
Net income attributable to common stockholders	$ 25,755	$ 29,558	$ 55,274	$ 168,385
Denominator:
Weighted average common shares outstanding-basic	70,799	69,788	70,640	69,594
Dilutive effect of options and warrants (in shares)	603	1,319	748	1,572
Weighted average common shares outstanding-diluted	71,402	71,107	71,388	71,166

Share-Based Compensation - Addi

Share-Based Compensation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2023	Apr. 01, 2022	Mar. 31, 2023	Apr. 01, 2022	Sep. 30, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation			$ 20,507	$ 19,916
Compensation cost not yet recognized	$ 70,400		$ 70,400
Unrecognized compensation cost period for recognition			2 years 1 month 6 days
Share-based compensation expense	9,460	$ 9,967	$ 20,507	19,916
Intrinsic value of options exercised	0			11,000
Years to maturity			3 years
Aggregate intrinsic value stock options outstanding	$ 800		$ 800
Number of stock options outstanding (in shares)	15,000		15,000
Weighted average exercise price per share (in dollars per share)	$ 16.06		$ 16.06
Weighted average remaining contractual term options outstanding			2 years 7 months 6 days
Incentive Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value of outstanding awards	$ 4,500		$ 4,500		$ 4,900
Employee-related Liabilities	2,100		2,100		$ 3,600
Share-based compensation	$ 500	$ 900	$ 1,800	600
Restricted Stock Restricted Stock Units And Performance Based Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards vested (in shares)			1,338,000
Vested in period fair value			$ 81,300	$ 89,300
Granted (in shares)			751,000
Granted (in usd per share)			$ 63.25
Shares forfeited (in shares)			39,000
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Years to maturity			2 years 10 months 24 days
Market Based Performance Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)			166,452
Granted (in usd per share)			$ 80.38
Shares forfeited (in shares)			0
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Term of options granted			4 years
Minimum | Incentive Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period			3 years
Minimum | Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period			3 years
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Term of options granted			7 years
Maximum | Incentive Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period			4 years
Maximum | Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period			4 years
2012 Omnibus Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Available for grant (in shares)	4,600,000		4,600,000
Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Available for grant (in shares)	1,300,000		1,300,000
Unrecognized compensation cost	$ 300		$ 300

Share-Based Compensation - Effe

Share-Based Compensation - Effects of Stock-Based Compensation Expense Related to Stock-Based Awards to Employees and Non-Employees (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2023	Apr. 01, 2022	Mar. 31, 2023	Apr. 01, 2022
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total share-based compensation expense	$ 9,460	$ 9,967	$ 20,507	$ 19,916
Cost of Revenue
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total share-based compensation expense	1,011	1,073	2,161	2,106
Research and Development
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total share-based compensation expense	3,742	3,511	7,974	7,110
Selling, General and Administrative
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total share-based compensation expense	$ 4,707	$ 5,383	$ 10,372	$ 10,700

Share-Based Compensation - Summ

Share-Based Compensation - Summary of Restricted Stock, Restricted Stock Unit and Performance-based Restricted Stock Unit Activity (Details) - Restricted Stock Restricted Stock Units And Performance Based Restricted Stock Units shares in Thousands	6 Months Ended
	Mar. 31, 2023 $ / shares shares
Number of shares (in thousands)
Balance at beginning of period (in shares) | shares	1,872
Granted (in shares) | shares	751
Vested and released (in shares) | shares	(1,338)
Performance-based adjustment (in shares) | shares	311
Forfeited, canceled or expired (in shares) | shares	(39)
Balance at end of period (in shares) | shares	1,557
Weighted- Average Grant Date Fair Value
Balance at beginning of period (in usd per share) | $ / shares	$ 40.44
Granted (in usd per share) | $ / shares	63.25
Vested and released (in usd per share) | $ / shares	28.11
Performance-based adjustment (in usd per share) | $ / shares	27.13
Forfeited, canceled or expired (in usd per share) | $ / shares	47.46
Balance at end of period (in usd per share) | $ / shares	$ 59.23

Share-Based Compensation - Fair

Share-Based Compensation - Fair Value of Market-Based PRSUs (Details)	6 Months Ended
	Mar. 31, 2023 USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Years to maturity	3 years
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant date stock price	$ 56.15
Average stock price at the start of the performance period	$ 54.12
Risk free interest rate	4.20%
Years to maturity	2 years 10 months 24 days
Expected volatility rate	52.40%
Expected dividend yield	0%

Share-Based Compensation Share-

Share-Based Compensation Share-Based Compensation Plans - Summary of Stock Option Activity (Details) $ / shares in Units, $ in Thousands	6 Months Ended
	Mar. 31, 2023 USD ($) $ / shares shares
Number of Shares
Ending Balance Stock options outstanding (in shares) | shares	15,000
Weighted-Average Exercise Price per Share
Ending Balance weighted-average exercise price per share (in usd per share) | $ / shares	$ 16.06
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Weighted average remaining contractual term options outstanding	2 years 7 months 6 days
Aggregate intrinsic value stock options outstanding | $	$ 800

Income Taxes (Details)

Income Taxes (Details) - USD ($)	3 Months Ended		6 Months Ended
	Mar. 31, 2023	Apr. 01, 2022	Mar. 31, 2023	Apr. 01, 2022	Sep. 30, 2022
Income Tax Disclosure [Abstract]
Income tax expense	$ 11,660,000	$ 1,569,000	$ 21,271,000	$ 3,026,000
Effective income tax rate	31.20%	5%	27.80%	1.80%
Effective tax rate			21%
Unrecognized tax benefit	$ 0		$ 0		$ 0

Geographic and Significant Cu_3

Geographic and Significant Customer Information - Additional Information (Details) - segment	3 Months Ended		6 Months Ended
	Mar. 31, 2023	Apr. 01, 2022	Mar. 31, 2023	Apr. 01, 2022
Revenue from External Customer [Line Items]
Number of reportable operating segment			1
Top Ten Customers | Revenue | Customer Concentration Risk
Revenue from External Customer [Line Items]
Concentration risk, percentage	48%	48%	49%	45%

Geographic and Significant Cu_4

Geographic and Significant Customer Information - Summary of Different Geographic Regions (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Sep. 30, 2022
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-Lived Assets	$ 123,266	$ 123,701
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-Lived Assets	117,606	108,569
Other Countries
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-Lived Assets	$ 5,660	$ 15,132

Uncategorized Items - mtsi-2023

Label	Element	Value
Accounting Standards Update [Extensible Enumeration]	us-gaap_AccountingStandardsUpdateExtensibleList	Accounting Standards Update 2020-06 [Member]