0001564590-21-016988 | 10-K | XBRL Viewer

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Document and Entity Information - USD ($) $ in Billions	12 Months Ended
Document and Entity Information - USD ($) $ in Billions	Jan. 31, 2021	Mar. 22, 2021	Jul. 31, 2020
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Jan. 31, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY
Trading Symbol	AMBA
Entity Registrant Name	AMBARELLA, INC.
Entity Central Index Key	0001280263
Current Fiscal Year End Date	--01-31
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		36,248,731
Entity Public Float			$ 1.6
Entity File Number	001-35667
Entity Tax Identification Number	98-0459628
Entity Address, Address Line One	3101 Jay Street
Entity Address, City or Town	Santa Clara
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	95054
City Area Code	408
Local Phone Number	734-8888
Entity Incorporation, State or Country Code	E9
Title of 12(b) Security	Ordinary Shares, $0.00045 Par Value Per Share
Security Exchange Name	NASDAQ
Entity Interactive Data Current	Yes
Document Annual Report	true
Document Transition Report	false
Documents Incorporated by Reference	Certain information is incorporated into Part III of this report by reference to the Proxy Statement for the Registrant’s annual meeting of shareholders to be held on or about June 17, 2021 to be filed with the Securities and Exchange Commission pursuant to Regulation 14A not later than 120 days after the end of the fiscal year covered by this Annual Report on Form 10-K.

Consolidated Balance Sheets - USD ($) $ in Thousands	Jan. 31, 2021	Jan. 31, 2020
Current assets:
Cash and cash equivalents	$ 241,274	$ 231,403
Marketable debt securities	199,434	173,345
Accounts receivable, net	24,974	18,487
Inventories	26,081	22,971
Restricted cash	10	9
Prepaid expenses and other current assets	5,531	4,975
Total current assets	497,304	451,190
Property and equipment, net	5,530	5,614
Deferred tax assets, non-current	10,914	10,400
Intangible assets, net	18,703	17,826
Operating lease right-of-use assets, net	9,659	9,935
Goodwill	26,601	26,601
Other non-current assets	4,569	5,710
Total assets	573,280	527,276
Current liabilities:
Accounts payable	21,124	14,910
Accrued and other current liabilities	48,126	34,970
Operating lease liabilities, current	2,911	2,181
Income taxes payable	962	691
Deferred revenue, current	844	701
Total current liabilities	73,967	53,453
Operating lease liabilities, non-current	7,525	7,975
Other long-term liabilities	16,812	17,776
Total liabilities	98,304	79,204
Commitments and contingencies (Note 14)	0	0
Shareholders' equity:
Preference shares, $0.00045 par value per share, 20,000,000 shares authorized and no shares issued and outstanding at January 31, 2021 and January 31, 2020, respectively	0	0
Ordinary shares, $0.00045 par value per share, 200,000,000 shares authorized at January 31, 2021 and January 31, 2020, respectively; 35,547,440 shares issued and outstanding at January 31, 2021; 33,805,609 shares issued and outstanding at January 31, 2020	16	15
Additional paid-in capital	347,458	261,220
Accumulated other comprehensive income	1,219	768
Retained earnings	126,283	186,069
Total shareholders’ equity	474,976	448,072
Total liabilities and shareholders' equity	$ 573,280	$ 527,276

Consolidated Balance Sheets (Parenthetical) - $ / shares	Jan. 31, 2021	Jan. 31, 2020
Statement Of Financial Position [Abstract]
Preference shares, par value	$ 0.00045	$ 0.00045
Preference shares, shares authorized	20,000,000	20,000,000
Preference shares, shares issued	0	0
Preference shares, shares outstanding	0	0
Ordinary shares, par value	$ 0.00045	$ 0.00045
Ordinary shares, shares authorized	200,000,000	200,000,000
Ordinary shares, shares issued	35,547,440	33,805,609
Ordinary shares, shares outstanding	35,547,440	33,805,609

Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2021	Jan. 31, 2020	Jan. 31, 2019
Income Statement [Abstract]
Revenue	$ 222,990	$ 228,732	$ 227,768
Cost of revenue	87,417	96,023	89,624
Gross profit	135,573	132,709	138,144
Operating expenses:
Research and development	140,759	129,724	128,084
Selling, general and administrative	55,980	52,634	50,480
Total operating expenses	196,739	182,358	178,564
Loss from operations	(61,166)	(49,649)	(40,420)
Other income, net	3,863	8,021	5,868
Loss before income taxes	(57,303)	(41,628)	(34,552)
Provision (benefit) for income taxes	2,483	3,164	(4,105)
Net loss	$ (59,786)	$ (44,792)	$ (30,447)
Net loss per share attributable to ordinary shareholders:
Basic	$ (1.72)	$ (1.35)	$ (0.93)
Diluted	$ (1.72)	$ (1.35)	$ (0.93)
Weighted-average shares used to compute net loss per share attributable to ordinary shareholders:
Basic	34,679,717	33,083,562	32,713,606
Diluted	34,679,717	33,083,562	32,713,606

Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2021	Jan. 31, 2020	Jan. 31, 2019
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (59,786)	$ (44,792)	$ (30,447)
Other comprehensive income, net of tax:
Net unrealized gains on investments	451	671	376
Other comprehensive income, net of tax	451	671	376
Comprehensive loss	$ (59,335)	$ (44,121)	$ (30,071)

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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+ Details

Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Total	Cumulative Effect of Change in Accounting Principle [Member]	Outstanding Ordinary Shares [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Retained Earnings [Member]	Retained Earnings [Member] Cumulative Effect of Change in Accounting Principle [Member]
Beginning Balance, Amount at Jan. 31, 2018	$ 482,187	$ 43	$ 15	$ 221,186	$ (279)	$ 261,265	$ 43
Beginning Balance, Shares at Jan. 31, 2018			33,489,614
Exercise of stock options, Amount	$ 1,285		$ 0	1,285	0	0
Exercise of stock options, Shares	232,205		232,205
Vesting of restricted stock units, Amount	$ 0		$ 0	0	0	0
Vesting of restricted stock units, Shares			920,826
Employee stock purchase plan, Amount	5,136		$ 0	5,136	0	0
Employee stock purchase plan, Shares			146,887
Stock repurchase, Amount	(99,903)		$ 0	(99,903)	0	0
Stock repurchase, Shares			(2,485,992)
Stock-based compensation expense related to stock awards granted to employees and consultants	60,812		$ 0	60,812	0	0
Net unrealized gains on investments - net of tax	376		0	0	376	0
Net loss	(30,447)		0	0	0	(30,447)
Ending Balance, Amount at Jan. 31, 2019	419,489		$ 15	188,516	97	230,861
Ending Balance, Shares at Jan. 31, 2019			32,303,540
Exercise of stock options, Amount	$ 5,695		$ 0	5,695	0	0
Exercise of stock options, Shares	366,886		366,886
Vesting of restricted stock units, Amount	$ 0		$ 0	0	0	0
Vesting of restricted stock units, Shares			957,319
Employee stock purchase plan, Amount	5,967		$ 0	5,967	0	0
Employee stock purchase plan, Shares			177,864
Stock-based compensation expense related to stock awards granted to employees and consultants	61,042		$ 0	61,042	0	0
Net unrealized gains on investments - net of tax	671		0	0	671	0
Net loss	(44,792)		0	0	0	(44,792)
Ending Balance, Amount at Jan. 31, 2020	$ 448,072		$ 15	261,220	768	186,069
Ending Balance, Shares at Jan. 31, 2020	33,805,609		33,805,609
Exercise of stock options, Amount	$ 10,333		$ 0	10,333	0	0
Exercise of stock options, Shares	421,736		421,736
Vesting of restricted stock units, Amount	$ 5,351		$ 1	5,350	0	0
Vesting of restricted stock units, Shares			1,162,883
Employee stock purchase plan, Amount	5,825		$ 0	5,825	0	0
Employee stock purchase plan, Shares			182,931
Stock repurchase, Amount	(1,000)		$ 0	(1,000)	0	0
Stock repurchase, Shares			(25,719)
Stock-based compensation expense related to stock awards granted to employees and consultants	65,730		$ 0	65,730	0	0
Net unrealized gains on investments - net of tax	451		0	0	451	0
Net loss	(59,786)		0	0	0	(59,786)
Ending Balance, Amount at Jan. 31, 2021	$ 474,976		$ 16	$ 347,458	$ 1,219	$ 126,283
Ending Balance, Shares at Jan. 31, 2021	35,547,440		35,547,440

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2021	Jan. 31, 2020	Jan. 31, 2019
Cash flows from operating activities:
Net loss	$ (59,786)	$ (44,792)	$ (30,447)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization	11,967	11,631	7,221
Amortization (accretion) of premium (discount) on marketable debt securities, net	721	(969)	(670)
Stock-based compensation	70,134	66,871	60,812
Deferred income taxes	(514)	187	(6,945)
Other non-cash items, net	65	(71)	350
Changes in operating assets and liabilities:
Accounts receivable	(6,487)	7,725	5,082
Inventories	(3,110)	(4,719)	5,131
Prepaid expenses and other current assets	(537)	1,057	(2,202)
Other non-current assets	1,141	(3,298)	(155)
Accounts payable	6,214	2,109	(7,014)
Accrued and other current liabilities	12,055	5,079	(8,302)
Income taxes payable	272	(302)	57
Deferred revenue	144	172	265
Operating lease liabilities	(2,416)	(2,851)	0
Other long-term liabilities	937	1,585	1,289
Net cash provided by operating activities	30,800	39,414	24,472
Cash flows from investing activities:
Purchases of investments	(219,677)	(225,913)	(207,841)
Sales of investments	70,087	96,363	66,211
Maturities of investments	123,208	122,795	65,428
Purchase of property and equipment	(1,952)	(1,821)	(2,940)
Purchase of intangible assets	(2,990)	0	0
Net cash used in investing activities	(31,324)	(8,576)	(79,142)
Cash flows from financing activities:
Proceeds from exercise of stock options and employee stock purchase plan	16,417	11,960	6,686
Stock repurchase	(1,000)	0	(99,904)
Payment for intangible assets	(5,021)	(5,444)	(4,735)
Net cash provided by (used in) financing activities	10,396	6,516	(97,953)
Net increase (decrease) in cash, cash equivalents and restricted cash	9,872	37,354	(152,623)
Cash, cash equivalents and restricted cash at beginning of period	231,412	194,058	346,681
Cash, cash equivalents and restricted cash at end of period	241,284	231,412	194,058
Supplemental disclosure of cash flow information:
Cash paid for income taxes	1,531	1,811	1,409
Supplemental disclosure of noncash investing activities:
Unpaid liabilities related to intangible and fixed assets purchases	$ 4,302	$ 12,284	$ 933

Organization and Summary of Significant Accounting Policies

12 Months Ended

Jan. 31, 2021

Accounting Policies [Abstract]

Organization and Summary of Significant Accounting Policies

1. Organization and Summary of Significant Accounting Policies

Organization

Ambarella, Inc. (the “Company”) was incorporated in the Cayman Islands on January 15, 2004. The Company is a leading developer of low-power semiconductor solutions offering high-definition (HD) and Ultra HD compression, image processing, and deep neural network processing. The Company combines its processor design capabilities with its expertise in video and image processing, algorithms and software to provide a technology platform that is designed to be easily scalable across multiple applications and enable rapid and efficient product development. The Company’s system-on-a-chip, or SoC, designs fully integrate high-definition video processing, image processing, artificial intelligence (AI) computer vision algorithms, audio processing and system functions onto a single chip, delivering exceptional video and image quality, differentiated functionality and low power consumption. The Company is currently addressing a broad range of human and computer vision applications, including professional and consumer security cameras, automotive cameras such as advanced driver assistance systems (ADAS), electronic mirrors, drive recorders, driver/cabin monitoring systems, autonomous driving, and industrial and robotic applications.

The Company sells its solutions to leading original design manufacturers, or ODMs, and original equipment manufacturers, or OEMs, globally.

Basis of Consolidation

The Company’s fiscal year ends on January 31. The consolidated financial statements of the Company and its subsidiaries have been prepared in conformity with accounting principles generally accepted in the United States (“U.S. GAAP”). All intercompany transactions and balances have been eliminated in consolidation.

Use of Estimates

The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expense during the reported periods. Actual results could differ from those estimates.

On an ongoing basis, management evaluates its estimates and assumptions, including those related to (i) write down of excess and obsolete inventories; (ii) the estimated useful lives of long-lived assets; (iii) the valuation of stock-based compensation awards and financial instruments; (iv) the probability of performance objectives achievement; (v) the realization of tax assets and estimates of tax liabilities, including reserves for uncertain tax positions. These estimates and assumptions are based on historical experience and on various other factors which the Company believes to be reasonable under the circumstances. The Company may engage third-party valuation specialists to assist with estimates related to the valuation of financial instruments, assets and stock awards associated with various contractual arrangements. Such estimates often require the selection of appropriate valuation methodologies and significant judgment. Actual results could differ from these estimates under different assumptions or circumstances and such differences could be material.

Concentration of Risk

The Company’s products are manufactured, assembled and tested by third-party contractors located primarily in Asia. The Company does not have long-term agreements with these contractors. A significant disruption in the operations of one or more of these contractors would impact the production of the Company’s products which could have a material adverse effect on its business, financial condition and results of operations.

A substantial portion of the Company’s revenue is derived from sales through one of its distributors, WT Microelectronics Co., Ltd., formerly Wintech Microelectronics Co., Ltd., or Wintech, which serves as its non-exclusive sales representative in Asia other than Japan, and directly to one ODM customer, Chicony Electronics Co., Ltd., or Chicony. Termination of the relationships with these customers could result in a temporary or permanent loss of revenue. Furthermore, any credit issues from these customers could impair their abilities to make timely payment to the Company. See Note 15 for additional information regarding revenue and credit concentration with these customers.

Financial instruments that potentially subject the Company to concentrations of credit risk consist primarily of cash, cash equivalents, marketable debt securities and accounts receivable. The Company maintains its cash primarily in checking accounts with reputable financial institutions. Cash deposits held with these financial institutions may exceed the amount of insurance provided on such deposits. The Company has not experienced any losses on deposits of its cash. In order to limit the exposure of each investment, the cash equivalents and marketable debt securities consist primarily of money market funds, asset-backed securities, commercial paper, U.S. government securities and debt securities of corporations which management assesses to be highly liquid. The Company does not hold or issue financial instruments for trading purposes.

The Company performs ongoing credit evaluation of its customers and adjusts credit limits based upon payment history and customers’ credit worthiness. The Company regularly monitors collections and payments from its customers.

Foreign Currency Transactions

The U.S. dollar is the functional currency for the Company and its subsidiaries. Monetary assets and liabilities denominated in non-U.S. currencies are re-measured to U.S. dollars using current exchange rates in effect at the balance sheet date. Nonmonetary assets and liabilities are re-measured to U.S. dollars using historical exchange rates. Monetary and other accounts are re-measured to U.S. dollars using average exchange rates in effect during each period. Gains or losses from foreign currency re-measurement are included in other income, net in the consolidated statements of operations, and, to date, have not been material.

Fair Value of Financial Instruments

Fair value accounting is applied to all financial assets and liabilities and non-financial assets and liabilities that are recognized or disclosed in the financial statements on a recurring basis. The carrying amounts reflected in the consolidated balance sheets for cash equivalents, accounts receivable, accounts payable, accrued liabilities and other current liabilities, approximate fair value due to the short-term nature.

Cash Equivalents and Marketable Debt Securities

The Company considers all highly liquid debt security investments with original maturities of less than three months at the time of purchase to be cash equivalents. Debt security investments that are highly liquid with original maturities at the time of purchase greater than three months are considered marketable debt securities.

The Company classifies the marketable securities as “available-for-sale” securities and record them at fair value based on quoted market prices of similar assets. On February 1, 2020, the Company adopted ASU No. 2016-13 (ASU 2016-13), Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, using the modified retrospective transition method. Under this new guidance, the Company recognizes credit losses based on a forward-looking current expected credit losses (CECL) model instead of the previous incurred loss model for financial instruments. The Company estimates the expected losses whenever a security’s fair value is below its amortized cost basis. The expected loss is computed at an individual security level using the discounted cash flow method with the effective interest rate on the purchase date. In the determination of credit-related losses, the Company excludes securities with zero loss expectations such as assets backed by government agencies. There are various factors considered in its assessment of credit-related losses, including the extent to which the fair value is less than the amortized cost basis, adverse conditions related to an industry or an underlying loan obligator, the payment structure of the security, changes to the rating of the security and other factors that may affect the security credit. The credit-related portion of the loss is recognized in other income (loss), net in the consolidated income statement but is limited to the difference between the fair value and the amortized cost basis of the security, adjusted for accrued interest. The non-credit-related portion of the loss is recognized in the accumulated other comprehensive income (loss) in the consolidated balance sheet. The cumulative effect adjustment upon the adoption on February 1, 2020 was immaterial and the credit-related losses from the Company’s financial instruments were not material as of January 31, 2021.

The Company measures the fair value of money market funds using quoted prices in active markets for identical assets and classifies them within Level 1. The fair value of the Company’s investments in other debt securities are obtained based on quoted prices for similar asserts in active markets, or model driven valuations using significant inputs derived from or corroborated by observable market data and are classified within Level 2. So far, the Company has no debt securities under unobservable inputs and classified within Level 3.

Restricted Cash

Amounts included in restricted cash represent those required to be set aside to secure certain transactions in a foreign entity. As of January 31, 2021 and 2020, the restricted cash was immaterial, respectively. The following table presents cash, cash equivalents and restricted cash reported on the consolidated balance sheets, and the sums are presented on the consolidated statements of cash flows:

	As of January 31,
	2021		2020		2019
	(in thousands)
Cash and cash equivalents	$	241,274	$	231,403	$	194,047
Restricted cash		10		9		11
Total as presented in the consolidated statements of cash flows	$	241,284	$	231,412	$	194,058

Trade Accounts Receivable and Allowance for Credit Losses

The Company’s accounts receivables are recorded at invoiced amounts less allowance for any credit losses. According to ASU 2016-13, the Company recognizes credit losses based on a forward-looking current expected credit losses (CECL). The Company makes estimates of expected credit losses based upon its assessment of various factors, including historical collection experience, the age of accounts receivable balances, credit quality of its customers, current economic conditions, reasonable and supportable forecasts of future economic conditions, and other factors that may affect its ability to collect from customers. The changes in allowance for credit losses are recognized in the consolidated statement of operations. The uncollectible accounts receivables are written off in the period in which a determination is made that all commercially reasonable means of recovering them have been exhausted. There were no material write-offs of accounts receivable for the fiscal years ended January 31, 2021, 2020 and 2019, respectively. There was no material current expected credit losses recorded as of January 31, 2021 and 2020, respectively.

Inventories

The Company records inventories at the lower of cost or net realizable value. The cost includes materials and other production costs and is computed using standard cost on a first-in, first-out basis. Inventory reserves are recorded for estimated obsolescence or unmarketable inventories based on forecast of future demand and market conditions. Any adjustments to reduce the cost of inventories to their net realizable value are recognized in earnings in the current period. Once inventory is written down, a new accounting cost basis is established and, accordingly, any associated reserve is not released until the inventory is sold or scrapped. There were no material inventory losses recognized for the fiscal years ended January 31, 2021, 2020 and 2019, respectively.

Property and Equipment

Property and equipment are stated at cost and depreciated using the straight-line method over the estimated useful life for computer equipment, computer software, machinery, equipment and furniture and fixtures. Leasehold improvements are amortized over the shorter of the lease term or their estimated useful lives. Repairs and maintenance are charged to expense as incurred.

Noncancelable Internal-Use Software License

The Company accounts for a noncancelable on premise internal-use software license as the acquisition of an intangible asset and the incurrence of a liability to the extent that all or a portion of the software licensing fees are not paid on or before the license acquisition date. The intangible asset and related liability are recorded at net present value and interest expense is recorded over the payment term.

Leases

Effective February 1, 2019, the Company adopted Accounting Standards Codification (“ASC”) Topic 842, Leases, using the alternative transition method with an adjustment to the opening balance in the period of adoption without adjustment of comparative period financial statements. Under this new guidance, the Company recognizes leases as operating lease right-of-use (“ROU”) assets and corresponding lease liabilities at the lease commencement date based on the present value of future lease payments, while recognizing lease expenses under straight-line method through the lease term. The Company also elected the other available practical expedients, and has elected not to recognize ROU assets and lease liabilities that arise from short-term (12 months or less) leases. The Company does not combine lease components with non-lease components, and as a result, the non-lease components are accounted for separately. In determining the present value of lease payments, the Company uses the implicit interest rate if readily determinable. When the implicit rate is not readily determinable, the Company uses its incremental borrowing rate based on the information available at the lease commencement date. The Company's leases mainly include its worldwide office facilities which are classified as operating leases. Certain leases include renewal options that are under the Company's discretion. The renewal options are included in the ROU assets and liability calculation if it is reasonably certain that the Company will exercise the option. The Company's short-term leases and finance leases are immaterial as of January 31, 2021 and January 31, 2020, respectively.

Goodwill and In-Process Research and Development

The Company does not amortize goodwill. Acquired in-process research and development, or IPR&D, is capitalized at fair value as an intangible asset and amortization commences upon completion of the underlying projects. When a project underlying reported IPR&D is completed, the corresponding amount of IPR&D is reclassified as an amortizable purchased intangible asset and is amortized over its estimated useful life. As of January 31, 2021, there was no IPR&D amortized.

Impairment of Long-Lived Assets Including Goodwill and Other Acquired Intangible Assets

The Company reviews property and equipment and intangible assets, excluding goodwill, for impairment at least annually in the fourth fiscal quarter or whenever events or changes in circumstances indicate that the carrying amount of an asset, or asset group, may not be recoverable. Determination of recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset, or asset group to estimated undiscounted future cash flows expected to be generated by the asset, or asset group. If the carrying amount of an asset or asset group exceeds its estimated undiscounted future cash flows, an impairment charge is recognized for the amount by which the carrying amount of the asset or asset group exceeds the estimated fair value of the asset or asset group. Fair value is determined based on the estimated discounted future cash flows expected to be generated by the asset or asset group. Events or changes in circumstances that may indicate that an asset is impaired include significant decreases in the market value of an asset, significant underperformance relative to expected historical or projected future results of operations, a change in the extent or manner in which an asset is utilized, significant declines in the estimated fair value of the overall Company for a sustained period, shifts in technology, loss of key management or personnel, changes in the Company’s operating model or strategy and competitive forces. There has been no occurrence of events to date that would trigger an impairment analysis. As such, no impairment charge has been recognized as of January 31, 2021.

The Company tests the goodwill for impairment at least annually in the fourth fiscal quarter, or sooner whenever events or changes in circumstances indicate that the asset may be impaired. The Company has a single reporting unit for goodwill impairment test purposes based on its business and reporting structure. The Company is permitted to first assess qualitative factors to determine whether the two step goodwill impairment test is necessary. Further testing is only required if the Company determines, based on the qualitative assessment, that it is more likely than not that a reporting unit’s fair value is less than its carrying amount. Otherwise, no further impairment testing is required. Qualitative factors include industry and market considerations, overall financial performance, and other relevant events and factors affecting the reporting unit. No goodwill impairment has been identified to date based on the Company’s qualitative factors assessment.

Equity Investment

The Company accounts for its investment in a privately held company as an equity investment and reports the investment in other non-current assets in the consolidated balance sheets. The Company chooses to measure this equity investment that does not have readily determinable fair value at cost minus any recorded impairments, adjusted for observable price changes in transactions for an identical or similar investment of the same issuer. Upon determining that an impairment or observable price change exists, the Company records any adjustment to the fair value of the investment through net income. To date, there have been no identified events or changes in circumstances that may have a significant effect on the fair value of this investment and the Company has not recognized any impairment losses related to this investment nor have there been any observable price changes.

Revenue Recognition

Effective February 1, 2018, the Company adopted ASC 606, Revenue from Contracts with Customers. As a result, the Company recognizes revenue when control of its goods and services is transferred to its customers. Revenue recognition is evaluated through the following five steps: (i) identification of the contract, or contracts, with a customer; (ii) identification of the performance obligations in the contract; (iii) determination of the transaction price; (iv) allocation of the transaction price to the performance obligations in the contract; and (v) recognition of revenue when or as a performance obligation is satisfied.

The sale of semiconductor products accounts for the substantial majority of the Company’s consolidated revenue. Sales agreements with customers are renewable periodically and contain terms and conditions with respect to payment, delivery, warranty, supply and other rights. The Company considers an accepted customer purchase order, governed by sales agreement, to be the contract with the customer. For each contract, the Company considers the promise to transfer tangible products to be the identified performance obligation. Product sales contracts may include volume-based tiered pricing or rebates that are fulfilled in cash or product. In determining the transaction price, the Company accounts for the right of returns, cash rebates, commissions and other pricing adjustments as variable consideration and estimates these amounts based on the expected amount to be provided to customers and reduces the revenue recognized. The Company estimates sales returns and rebates based on the Company’s historical patterns of return and pricing credits. As the Company’s standard payment terms are 30 days to 60 days, the contracts have no financing component. Under ASC 606, the Company estimates the total consideration to be received by using the expected value method for each contract, computes weighted average selling price for each unit shipped in cases where there is a material right due to the presence of volume-based tiered pricing, allocates the total consideration between the identified performance obligations, and recognizes revenue when control of its goods and services is transferred to its customers. The Company considers product control to be transferred at a point in time upon shipment or delivery because the Company has a present right to payment at that time, the customer has legal title to the asset, the Company has transferred physical possession of the asset, and the customer has significant risk and rewards of ownership of the asset.

The Company also enters into fixed-price engineering service agreements with certain customers. These agreements may include multiple performance obligations, such as software development services, licensing of intellectual property and post-contract customer support, or PCS. These multiple performance obligations are highly interdependent, highly interrelated, are typically not sold separately and do not have standalone selling prices. They are all inputs to generate one combined output which is incorporating the Company’s SoC into the customer’s product. Accordingly, the Company determines that they are not separately identifiable and shall be treated as a single performance obligation. Customers usually pay based on milestones achieved. Because payments received do not correspond directly with the value of the Company’s performance to date, for fixed-price engineering services arrangements, revenue is recognized using the time-based straight line method, which best depicts the Company’s performance toward complete satisfaction of the performance obligation based on the nature of such professional services. Revenues from engineering service agreements were not material for the fiscal years ended January 31, 2021, 2020 and 2019, respectively.

Timing of revenue recognition may differ from the timing of invoicing to the Company’s customers. The Company records contract assets when revenue is recognized prior to invoicing. The Company’s contract assets are primarily related to satisfied but unbilled performance obligations associated with its engineering service agreements at the reporting date. As of January 31, 2021 and 2020, the contract assets for these unbilled receivables were not material. The Company’s contract liabilities consist of deferred revenue. The deferred revenue is primarily related to the portion of a transaction price that exceeds the weighted average selling price for products sold to date under tiered-pricing contracts which contain material rights. This deferred revenue is expected to be recognized over the course of the contract when products are delivered for future pricing below the weighted average selling price of the contract. For the twelve months ended January 31, 2021 and 2020, the Company did not recognize any material revenue adjustment, respectively, related to performance obligations satisfied in prior periods released from this deferred revenue. As of January 31, 2021 and 2020, the respective deferred revenues were not material. Additionally, the transaction price allocated to unsatisfied, or partially unsatisfied, purchase orders for contracts that are greater than a year was not material as of January 31, 2021 and 2020, respectively. The Company also elects not to disclose the value of unsatisfied or partially unsatisfied performance obligations due to original expected contract duration of one year or less and elects to exclude amounts collected from customers for all sales taxes from the transaction price.

Cost of Revenue

Cost of revenue includes cost of materials, cost associated with packaging and assembly, testing and shipping, cost of personnel, stock-based compensation, logistics and quality assurance, warranty cost, royalty expense, write-downs of inventories and allocation of overhead.

Research and Development

Research and development costs are expensed as incurred and consist primarily of personnel costs, product development costs, which include engineering services, development software and hardware tools, license fees, costs of fabrication of masks for prototype products, other development materials costs, depreciation of equipment and tools and allocation of facility costs, net of any research and development grants. As of January 31, 2021, there was approximately $1.4 million of grants recorded in prepaid expenses and other current assets and approximately $2.0 million of grants recorded in other non-current assets in the consolidated balance sheets.

Selling, General and Administrative

Selling, general and administrative expenses consist of personnel costs, travel and trade show costs, legal expenses, other professional services and occupancy costs. Advertising expenses were not material for the fiscal years ended January 31, 2021, 2020 and 2019, respectively.

Stock-Based Compensation

The Company measures stock-based compensation for equity awards granted to employees and directors based on the estimated fair value on the grant date, and recognizes that compensation as expense using the straight-line attribution method for service condition awards or using the graded-vesting attribution method for awards with performance conditions over the requisite service period, which is typically the vesting period of each award. The Company determines the fair value of restricted stock and restricted stock units with service or performance conditions based on the fair market value of its ordinary shares on the grant date. The Company uses the Black-Scholes option pricing model to determine the fair value of stock options. Determining the fair value of stock options on the grant date requires the input of various assumptions, including stock price of the underlying ordinary share, the exercise price of the stock option, expected volatility, expected term, risk-free interest rate and dividend rate. The Company calculates expected volatility based on its own historical stock price for a period commensurate with the expected term, which is computed based on its own historical exercise behavior. The risk-free interest rate is derived from an average of the U.S. Treasury constant maturity rates for the respective periods most closely commensurate with the expected term. The expected dividend yield is zero because the Company has not historically paid dividends and has no present intention to pay dividends. The Company uses the Lattice pricing model and Monte Carlo Simulation to evaluate the fair value of awards with market conditions, including assumptions of historical volatility and risk-free interest rate commensurate with the vesting term. The Company elects to account for forfeitures as they occur.

Income Taxes

The Company records income taxes using the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been recognized in its financial statements or tax returns. In estimating future tax consequences, generally all expected future events other than enactments or changes in the tax law or rates are considered. Valuation allowances are provided when necessary to reduce deferred tax assets to the amount expected to be realized.

The Company applies authoritative guidance for the accounting for uncertainty in income taxes. The guidance requires that tax effects of a position be recognized only if it is “more likely than not” to be sustained based solely on its technical merits as of the reporting date. Upon estimating its tax positions and tax benefits, the Company considers and evaluates numerous factors, which may require periodic adjustments and which may not reflect the final tax liabilities. The Company adjusts its financial statements to reflect only those tax positions that are more likely than not to be sustained under examination.

As part of the process of preparing consolidated financial statements, the Company is required to estimate its taxes in each of the jurisdictions in which it operates. The Company estimates actual current tax exposure together with assessing temporary differences resulting from differing treatment of items, such as accruals and allowances not currently deductible for tax purposes. These differences result in deferred tax assets, which are included in the consolidated balance sheets. In general, deferred tax assets represent future tax benefits to be received when certain expenses previously recognized in the consolidated statements of operations become deductible expenses under applicable income tax laws, or loss or credit carryforwards are utilized.

In assessing whether deferred tax assets may be realized, the Company considers whether it is more likely than not that some portion or all of deferred tax assets will be realized. The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income.

The Company makes estimates and judgments about its future taxable income based on assumptions that are consistent with its plans and estimates. Should the actual amounts differ from estimates, the amount of valuation allowance could be materially impacted. Any adjustment to the deferred tax asset valuation allowance would be recorded in the consolidated income statement for the periods in which the adjustment is determined to be required.

Net Income (Loss) Per Ordinary Share

Basic earnings (losses) per share is computed by dividing net income (loss) available to ordinary shareholders by the weighted-average number of ordinary shares outstanding during the period. Diluted earnings (losses) per share is computed by dividing net income (loss) available to ordinary shareholders by the weighted-average number of ordinary shares outstanding during the period increased to include the number of additional ordinary shares that would have been outstanding if the potentially dilutive securities had been issued. Potentially dilutive securities include outstanding stock options, shares to be purchased under the Company’s employee stock purchase plan, unvested restricted stock and restricted stock units. The dilutive effect of potentially dilutive securities is reflected in diluted earnings (losses) per share by application of the treasury stock method.

Comprehensive Income (Loss)

Comprehensive income (loss) includes unrealized gains or losses from available-for-sale securities that are excluded from net income (loss).

Recent Accounting Pronouncements

In December 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes. The amendments in this ASU simplify the accounting for income taxes by removing certain exceptions to the general principles in Topic 740. The amendments also improve consistent application of and simplify GAAP for other areas of Topic 740 by clarifying and amending existing guidance. The amendments are effective for public entities in fiscal years beginning after December 15, 2020, including interim periods within those fiscal years. Early adoption is permitted. The Company did not early adopt and believes the adoption of this new guidance will not have a material impact on its consolidated financial statements and disclosures.

In January 2020, the FASB issued ASU 2020-01 - Investments - Equity securities (Topic 321), Investments - Equity method and joint ventures (Topic 323), and Derivatives and hedging (Topic 815) - Clarifying the interactions between Topic 321, Topic 323, and Topic 815. The amendments in this Update improve the accounting for certain equity securities upon the application or discontinuation of the equity method of accounting and clarify the scope considerations for forward contracts and purchased options on certain securities. The amendments are effective for public entities in fiscal years beginning after December 15, 2020, including interim periods within those fiscal years. Early adoption is permitted. The Company did not early adopt and believes the adoption of this new guidance will not have a material impact on its consolidated financial statements and disclosures.

In October 2020, the FASB issued ASU 2020-08, Codification Improvements to Subtopic 310-20, Receivables – Nonrefundable Fees and Other Costs. The amendments in this Update clarify that at each reporting date an entity should reevaluate whether a callable debt security is within scope of this guidance, which has explicit, noncontingent call options that are callable at fixed prices and on preset dates at prices less than the amortized cost basis of the security. For each reporting period, if amortization basis for each individual callable debt security exceeds the amount repayable by the issuer at the next call date, the premium shall be amortized to the next call date. The amendments are effective for public entities in fiscal years beginning after December 15, 2020, including interim periods within those fiscal years. Early adoption is not permitted. The Company did not early adopt and believes the adoption of this new guidance will not have a material impact on its consolidated financial statements and disclosures.

In October 2020, the FASB issued ASU 2020-10, Codification Improvements. The amendments in this Update improves consistency by amending the Codification to include all disclosure guidance in the appropriate sections and clarifies application of various provisions in the Codification by amending and adding new headings, cross referencing to other guidance, and refining or correcting terminology. The amendments are effective for public entities in fiscal years beginning after December 15, 2020, including interim periods within those fiscal years. Early adoption is permitted. The Company did not early adopt and believes the adoption of this new guidance will not have a material impact on its consolidated financial statements and disclosures.

Financial Instruments and Fair Value

12 Months Ended

Jan. 31, 2021

Investments All Other Investments [Abstract]

Financial Instruments and Fair Value

2. Financial Instruments and Fair Value

The Company invests a portion of its cash in debt securities that are denominated in United States dollars. The investment portfolio consists of money market funds, asset-backed securities, commercial paper, U.S. government securities and debt securities of corporations. All of the investments are classified as available-for-sale securities and reported at fair value in the consolidated balance sheets as follows:

	As of January 31, 2021
	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
	(in thousands)
Money market funds	$	171	$	—	$	—		$	171
Commercial paper		66,181		—		—			66,181
Corporate bonds		102,108		980		(7	)		103,081
Asset-backed securities		15,740		164		—			15,904
U.S. government securities		29,383		82		—			29,465
Total cash equivalents and marketable debt securities	$	213,583	$	1,226	$	(7	)	$	214,802

	As of January 31, 2020
	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
	(in thousands)
Money market funds	$	8,284	$	—	$	—		$	8,284
Commercial paper		63,390		—		—			63,390
Corporate bonds		95,053		653		—			95,706
Asset-backed securities		23,062		69		(2	)		23,129
U.S. government securities		20,524		48		—			20,572
Total cash equivalents and marketable debt securities	$	210,313	$	770	$	(2	)	$	211,081

As of January 31, 2021, there were no debt securities with unrealized losses for more than twelve months.

	As of
	January 31, 2021		January 31, 2020
	(in thousands)
Included in cash equivalents	$	15,368	$	37,736
Included in marketable debt securities		199,434		173,345
Total cash equivalents and marketable debt securities	$	214,802	$	211,081

The contractual maturities of the investments at January 31, 2021 and 2020 were as follows:

	As of
	January 31, 2021		January 31, 2020
	(in thousands)
Due within one year	$	135,899	$	146,267
Due within one to three years		78,903		64,814
Total cash equivalents and marketable debt securities	$	214,802	$	211,081

The unrealized gains and losses on the available-for-sale securities were primarily caused by fluctuations in market value and interest rates as a result of the economic environment. Upon adoption of ASU No. 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, the Company estimates the expected losses at an individual security level whenever a security’s fair value is below its amortized cost basis using the discounted cash flow method. The credit-related portion of the loss is recognized in other income, net in the condensed consolidated statements of operations but is limited to the difference between the fair value and the amortized cost basis of the security, adjusted for accrued interest. The non-credit-related portion of the loss is recognized in accumulated other comprehensive income in the condensed consolidated balance sheets. The credit-related losses of the Company’s financial instruments were not material for the fiscal year ended January 31, 2021. The net amounts of unrealized gains and unrealized losses that are not credit-related are recognized in other comprehensive income.

The following fair value hierarchy is applied for disclosure of the inputs used to measure fair value. This hierarchy prioritizes the inputs into three broad levels as follows:

Level 1—Inputs are unadjusted quoted prices in active markets for identical assets or liabilities.

Level 2—Inputs are quoted prices for similar assets and liabilities in active markets or inputs that are observable for the assets or liabilities, either directly or indirectly through market corroboration, for substantially the full term of the financial instruments.

Level 3—Unobservable inputs based on the Company’s own assumptions used to measure assets and liabilities at fair value. The inputs require significant management judgment or estimation.

The following tables present the fair value of the financial instruments measured on a recurring basis as of January 31, 2021 and 2020, respectively:

	As of January 31, 2021
	Total		Level 1		Level 2		Level 3
	(in thousands)
Money market funds	$	171	$	171
Commercial paper		66,181				66,181
Corporate bonds		103,081				103,081
Asset-backed securities		15,904				15,904
U.S. government securities		29,465				29,465
Total cash equivalents and marketable debt securities	$	214,802	$	171	$	214,631	$	—

	As of January 31, 2020
	Total		Level 1		Level 2		Level 3
	(in thousands)
Money market funds	$	8,284	$	8,284	$	—	$	—
Commercial paper		63,390		—		63,390		—
Corporate bonds		95,706		—		95,706		—
Asset-backed securities		23,129		—		23,129		—
U.S. government securities		20,572		—		20,572		—
Total cash equivalents and marketable debt securities	$	211,081	$	8,284	$	202,797	$	—

Inventories

12 Months Ended

Jan. 31, 2021

Inventory Disclosure [Abstract]

Inventories

3. Inventories

Inventories at January 31, 2021 and 2020 consisted of the following:

	As of January 31,
	2021		2020
	(in thousands)
Work-in-progress	$	18,219	$	10,133
Finished goods		7,862		12,838
Total	$	26,081	$	22,971

Property and Equipment, Net

12 Months Ended

Jan. 31, 2021

Property Plant And Equipment [Abstract]

Property and Equipment, Net

4. Property and Equipment, net

Depreciation expense was approximately $2.6 million, $2.8 million and $2.6 million for the fiscal years ended January 31, 2021, 2020 and 2019, respectively. Property and equipment at January 31, 2021 and 2020 consisted of the following:

	As of January 31,
	2021			2020
	(in thousands)
Computer equipment and software	$	11,525		$	10,282
Machinery and equipment		6,946			6,317
Furniture and fixtures		969			969
Leasehold improvements		2,237			2,356
Construction in progress		331			63
		22,008			19,987
Less: accumulated depreciation and amortization		(16,478	)		(14,373	)
Total property and equipment, net	$	5,530		$	5,614

Intangible Assets, Net

12 Months Ended

Jan. 31, 2021

Goodwill And Intangible Assets Disclosure [Abstract]

Intangible Assets, Net

5. Intangible Assets, net

The intangible assets primarily consist of $4.1 million of in-process research and development (“IPR&D”) from the acquisition of VisLab S.r.l., or VisLab, in June 2015 and $14.6 million of noncancelable software licenses, net of amortization expense. Acquired IPR&D is capitalized at fair value and the amortization commences upon completion of the underlying projects. Once research and development efforts are completed, the corresponding amount of IPR&D is reclassified as an amortizable purchased intangible asset and is amortized over its estimated useful life. As of January 31, 2021, there was no IPR&D amortized. The Company will determine the project incorporating the VisLab IPR&D to be completed when a related chip begins mass production to address the level 3 and above advanced driving assistance systems markets.

The Company enters into certain internal-use noncancelable software license agreements with third parties from time-to-time. The licenses have been capitalized as intangible assets, and the corresponding future payments have been recorded as liabilities at net present value. As of January 31, 2021, $5.6 million was recorded in accrued and other current liabilities and $6.3 million was recorded in other long-term liabilities in the consolidated balance sheets.

The carrying amounts of intangible assets as of January 31, 2021 and 2020 were as follows:

	As of January 31, 2021							As of January 31, 2020
	Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount		Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount
	(in thousands)
In-process research and development	$	4,100	$	—		$	4,100	$	4,100	$	—		$	4,100
Software licenses		21,043		(6,440	)		14,603		27,203		(13,477	)		13,726
Total acquired intangible assets	$	25,143	$	(6,440	)	$	18,703	$	31,303	$	(13,477	)	$	17,826

During the twelve months ended January 31, 2021, there was approximately $13.5 million of software licenses retired. The amortization expense related to these software licenses was approximately $6.5 million, $5.9 million, and $4.7 million for the fiscal years ended January 31, 2021, 2020, and 2019 respectively. The expected annual amortization expense related to these software licenses as of January 31, 2021 is as follows:

	As of
	January 31, 2021
Fiscal Year	(in thousands)
2022	$	5,926
2023		6,269
2024		2,408
2025		—
2026		—
Thereafter		—
Total future amortization expenses:	$	14,603

There were no intangible asset impairments for the fiscal years ended January 31, 2021, 2020 and 2019, respectively.

Goodwill

12 Months Ended

Jan. 31, 2021

Goodwill And Intangible Assets Disclosure [Abstract]

Goodwill

6. Goodwill

On June 25, 2015, the Company completed the acquisition of VisLab, a privately-held Italian company that develops computer vision and intelligent control systems for automotive and other commercial applications, including advanced driver assistance systems and several generations of autonomous vehicle driving systems, for $30.0 million in cash. As a result, there was $25.3 million attributed to goodwill, $4.1 million attributed to intangible assets and $0.6 million attributed to net assets acquired. A deferred tax liability of $1.3 million related to the intangible assets was recorded to account for the difference between financial reporting and tax basis at the acquisition date, with an addition to goodwill. The Company does not amortize goodwill. There were no goodwill impairments for the fiscal years ended January 31, 2021, 2020 and 2019, respectively.

Accrued and Other Current Liabilities

12 Months Ended

Jan. 31, 2021

Payables And Accruals [Abstract]

Accrued and Other Current Liabilities

7. Accrued and Other Current Liabilities

Accrued and other current liabilities at January 31, 2021 and 2020 consisted of the following:

	As of January 31,
	2021		2020
	(in thousands)
Accrued employee compensation	$	18,105	$	16,874
Accrued rebates		391		54
Accrued product development costs		21,157		10,885
Software license liabilities, current		5,582		4,388
Other accrued liabilities		2,891		2,769
Total accrued and other current liabilities	$	48,126	$	34,970

The timing of SoC development progress and payments to outside foundries resulted in fluctuation of the accrued product development costs.

Leases

12 Months Ended

Jan. 31, 2021

Leases [Abstract]

Leases

8. Leases

The Company has entered into various operating leases for its worldwide office buildings and research and development facilities. For the fiscal year ended January 31, 2020, the Company exercised the renewal option to extend its U.S. office lease for a period of 63 months beginning from June 1, 2020 through August 31, 2025 and renewed its Shanghai office lease for another two years beginning from December 1, 2019 to November 30, 2021. The Company accounted these two renewed contracts as lease modifications and recorded an increase to the operating lease right-of-use assets and corresponding operating lease liabilities by approximately $4.0 million, respectively, in the consolidated balance sheets.

In August 2019, the Company also signed a separate lease for additional space for its U.S. office for a period of 56 months beginning from January 1, 2021 through August 31, 2025. In October 2020, the expansion premise lease agreement was amended to allow the Company to access the additional space one month early starting from the December 1, 2020. The Company recorded an increase to the operating lease right-of-use assets and corresponding operating lease liabilities by approximately $1.6 million, respectively, in the consolidated balance sheet upon commencement date on December 1, 2020.

In August 2019, VisLab, a wholly-owned subsidiary, was granted a land lease for 35 years with an obligation to construct a building on the land in line with architectural requirements from the lessor in Parma, Italy (“Parma lease”). The Company will be responsible for the costs of construction and occupy the building after completion of construction for the remainder of the lease term. At the end of the lease, the land together with the building and all of the improvements will revert to the lessor. The Parma lease will be recorded in the balance sheet upon completion of the building construction, which is expected to be two years after the lease inception date. Any payments made prior to completion of construction will be recorded as prepayments of the lease in other non-current assets in the consolidated balance sheets. There have been no payments made for the fiscal year ended January 31, 2021. The total estimated future undiscounted cash payments are approximately $2.2 million, of which $1.8 million will be paid in the construction phase and the remaining balance of $0.4 million will be paid over the remainder of the lease term.

For the fiscal year ended January 31, 2021 and January 31, 2020, the Company recorded approximately $3.0 million of operating lease expense under ASC 842. Approximately $4.6 million of operating lease expense was recorded for the fiscal year ended January 31, 2019 under ASC 840. The Company's short-term leases and finance leases are immaterial as of January 31, 2021.

Supplemental cash flow information related to leases is as follows:

	Year Ended
	January 31, 2021
	(in thousands)
Cash paid for operating leases included in operating cash flows	$	2,416
Supplemental non-cash information related to lease liabilities arising from obtaining right-of-use assets	$	348
Leased assets obtained in exchange for operating lease liabilities arising from lease modifications	$	2,440

As of January 31, 2021, the weighted average remaining lease term is 4.32 years, and the weighted average discount rate is 4.11 percent. Future minimum lease payments for the lease liabilities, excluding the Parma lease described above, are as follows:

	As of
	January 31, 2021
Fiscal Year	(in thousands)
2022	$	3,217
2023		2,315
2024		2,095
2025		2,153
2026		1,171
Thereafter		277
Total future annual minimum lease payments		11,228
Less: interest		(792	)
Total lease liabilities	$	10,436

Other Long-Term Liabilities

12 Months Ended

Jan. 31, 2021

Other Liabilities Disclosure [Abstract]

Other Long-Term Liabilities

9. Other Long-Term Liabilities

Other long-term liabilities at January 31, 2021 and 2020 consisted of the following:

	As of January 31,
	2021		2020
	(in thousands)
Unrecognized tax benefits, including interest	$	8,966	$	8,261
Deferred tax liabilities, non-current		1,288		1,288
Software license liabilities, non-current		6,259		8,159
Other long-term liabilities		299		68
Total other long-term liabilities	$	16,812	$	17,776

Capital Stock

12 Months Ended

Jan. 31, 2021

Equity [Abstract]

Capital Stock

10. Capital Stock

Preference shares

After completion of the Company’s initial public offering, or IPO in 2012, a total of 20,000,000 preference shares, with a $0.00045 par value per share, were authorized. There were no preference shares issued and outstanding as of January 31, 2021 and 2020, respectively.

Ordinary shares

As of January 31, 2021 and January 31, 2020, the following ordinary shares were reserved for future issuance under the EIP and ESPP:

	As of January 31,
	2021		2020
Shares reserved for options, restricted stock and restricted stock units		5,981,741		6,045,108
Shares reserved for employee stock purchase plan		2,299,143		2,059,504

Shares repurchased

On May 29, 2019, the Company’s Board of Directors authorized a program to repurchase up to $50.0 million of the Company’s ordinary shares commencing immediately through June 30, 2020. On March 16, 2020, the Company repurchased a total of 25,719 shares for approximately $1.0 million in cash. On May 29, 2020, the Board approved an extension of this program for an additional twelve months, ending June 30, 2021. Since the inception of the repurchase programs in June 2016, a total of $275.0 million has been authorized and a total of 4,011,595 shares have been repurchased for approximately $175.8 million in cash. Repurchases may be made from time-to-time through open market purchases, 10b5-1 plans or privately negotiated transactions subject to market conditions, applicable legal requirements and other relevant factors. The repurchase program does not obligate the Company to acquire any particular amount of ordinary shares, and it may be suspended at any time at the Company’s discretion. The repurchase program is funded using the Company’s working capital and any repurchased shares are recorded as authorized but unissued shares. As of January 31, 2021, there was $49.0 million available for repurchases under the repurchase program through June 30, 2021.

Employee Benefits and Stock-based Compensation

12 Months Ended

Jan. 31, 2021

Postemployment Benefits [Abstract]

Employee Benefits and Stock-based Compensation

11. Employee Benefits and Stock-based Compensation

401(k) Plan

The Company maintains a defined contribution 401(k) plan (the “401(k) Plan”) for all of its eligible U.S. employees. Under the 401(k) Plan, eligible employees may contribute up to the Internal Revenue Service annual contribution limitation. The Company is responsible for administrative costs of the Plan. The Company has not had any matching contributions to date.

Stock Option Plans

2004 Stock Plan. The 2004 Stock Plan provides for the grant of incentive stock options (“ISOs”) within the meaning of Section 422 of the Internal Revenue Code of 1986, as amended (the “Code”), nonstatutory stock options (“NSOs”), stock purchase rights to acquire restricted stock and restricted stock units. Upon the completion of the IPO, no additional awards will be granted under the 2004 Plan and the 2004 Plan was terminated. However, all outstanding stock options and other awards previously granted under the 2004 Plan will remain subject to the terms of the 2004 Plan.

2012 Equity Incentive Plan. The 2012 Equity Incentive Plan, or EIP, permits the grant of ISOs, within the meaning of Section 422 of the Code, to employees of the Company and any of the Company’s subsidiary corporations, and the grant of NSOs, stock appreciation rights, restricted stock, restricted stock units, performance units, performance shares, deferred stock units and dividend equivalents to employees, directors and consultants of the Company and any of the Company’s subsidiary corporations’ employees and consultants.

The exercise price of ISOs granted to a holder of more than 10% of the voting power of all classes of the Company’s shares shall be no less than 110% of fair market value on the grant date. The exercise price of ISOs granted to other employees and NSOs shall be no less than 100% of fair market value on the grant date. Options granted under the Plan have a term of up to 10 years from grant date. Options granted to new employees generally vest 25% on the first anniversary service date of the grant and remainder vest ratably over the following 36 months.

Restricted stock and restricted stock units granted to new employees generally vest as to 1/4th of the shares on the first anniversary service date of the grant and 1/16th of the shares vest every 3 months thereafter, so as to be 100% vested on the fourth anniversary of the vesting commencement date.

Vesting schedules for other service condition, market condition or performance condition awards vary and are subject to approval by the board of directors; provided that the performance condition associated awards shall not vest at all until the performance conditions are achieved and are subject to the award’s holders continuing to provide services to the Company through such vesting dates. The performance condition awards are automatically forfeited in their entirety, without any cost to or action by the Company, if there has been no achievement of the performance. The holders of restricted stock have voting power and other rights with respect to such shares, provided, however, that such shares are held in escrow and subject to forfeiture until the shares vested.

In the first quarter of fiscal year 2021 and 2020, the Company added 1,521,252 and 1,453,659 ordinary shares, respectively, to the ordinary shares reserved for issuance, pursuant to an “evergreen” provision contained in the EIP. Pursuant to such provision, on February 1st of each fiscal year, the number of ordinary shares reserved for issuance under the EIP is automatically increased by a number equal to the lesser of (i) 3,500,000 ordinary shares, (ii) four and one half percent (4.5%) of the aggregate number of ordinary shares outstanding on January 31st of the preceding fiscal year, or (iii) a lesser number of shares that may be determined by the Company’s Board of Directors.

Amended and Restated 2012 Employee Stock Purchase Plan. The Amended and Restated 2012 Employee Stock Purchase Plan, or ESPP, permits eligible participants to purchase ordinary shares at a discount through contributions up to 15% of their eligible compensation, subject to any IRS limitations. The ESPP provides each offering and purchasing period of six months in duration. The purchase price is 85% of the lower of the closing price of the Company’s ordinary shares on the first trading day of each offering period or on the purchase date.

In the first quarter of fiscal year 2021 and 2020, the Company added 422,570 and 403,794 ordinary shares, respectively, to the ordinary shares reserved for issuance, pursuant to an “evergreen” provision contained in the ESPP. Pursuant to such provision, on February 1st of each fiscal year, the number of ordinary shares reserved for issuance under the ESPP is automatically increased by a number equal to the lesser of (i) 1,500,000 ordinary shares, (ii) one and one quarter percent (1.25%) of the aggregate number of ordinary shares outstanding on such date, or (iii) an amount determined by the Company’s Board of Directors or a duly authorized committee of the Board of Directors.

Stock-based Compensation

The following table presents the classification of stock-based compensation for the periods indicated:

	Year Ended January 31,
	2021		2020		2019
	(in thousands)
Stock-based compensation:
Cost of revenue	$	1,328	$	1,184	$	1,261
Research and development		42,903		41,842		37,432
Selling, general and administrative		25,903		23,845		22,119
Total stock-based compensation	$	70,134	$	66,871	$	60,812

For the twelve months ended January 31, 2021, approximately $4.4 million of stock-based compensation expense was accrued in accrued and other current liabilities in the consolidated balance sheets. As of January 31, 2021, total unrecognized compensation cost related to unvested stock options was $3.1 million and is expected to be recognized over a weighted-average period of 2.40 years. Total unrecognized compensation cost related to unvested restricted stock units was $123.9 million and is expected to be recognized over a weighted-average period of 2.35 years. The restricted stock awards were fully vested as of January 31, 2021.

The following table sets forth the weighted-average assumptions used to estimate the fair value of the stock options and employee stock purchase plan awards for the periods indicated:

	Year Ended January 31,
	2021			2020			2019
Stock Options:
Volatility		52	%		52	%		54	%
Risk-free interest rate		0.52	%		1.82	%		2.77	%
Expected term (years)		5.78			6.01			5.41
Dividend yield		0	%		0	%		0	%
Employee stock purchase plan awards:
Volatility		59	%		47	%		45	%
Risk-free interest rate		0.21	%		2.23	%		2.15	%
Expected term (years)		0.5			0.5			0.5
Dividend yield		0	%		0	%		0	%

Starting from fiscal year 2019, the Company calculates expected volatility for stock options based on its own historical stock price for a period commensurate with the expected term. In the prior fiscal year, the Company calculated expected volatility for stock options based on the weighted average of historical volatilities of its own stock price and the stock prices of similar companies that are publicly available for a period commensurate with the expected term. The Company calculates expected volatility for ESPP based on its own historical stock price for a period commensurate with the offering period.

The following table summarizes stock option activities for the periods indicated:

	Option Outstanding
										Weighted-
								Total Intrinsic		Average
						Weighted-		Value of		Remaining		Aggregate
				Weighted-		Average		options		Contractual		Intrinsic
				Average		Grant-date		Exercised		Term		Value
	Shares			Exercise Price		Fair Value		(in thousands)		(in years)		(in thousands)
Outstanding at January 31, 2018		1,611,344		$	24.56
Granted		116,600			42.73	$	21.75
Exercised		(232,205	)		5.54			$	8,867
Forfeited		(20,974	)		53.50
Expired		(15,701	)		54.35
Outstanding at January 31, 2019		1,459,064			28.31
Granted		66,850			50.56	$	25.35
Exercised		(366,886	)		15.52			$	13,263
Forfeited		(14,931	)		46.29
Expired		(19,451	)		64.53
Outstanding at January 31, 2020		1,124,646			32.93
Granted		51,200			59.54	$	28.37
Exercised		(421,736	)		24.52			$	19,401
Forfeited		(11,618	)		46.69
Expired		(23,349	)		70.11
Outstanding at January 31, 2021		719,143		$	38.33					4.42		$	40,358
Exercisable at January 31, 2021		592,729		$	35.27						3.56	$	35,092

The intrinsic value of options outstanding and exercisable is calculated based on the difference between the fair market value of the Company’s ordinary shares on the reporting date and the exercise price. The closing price of the Company’s stock was $94.36 on January 29, 2021, as reported by The NASDAQ Global Market. The intrinsic value of exercised options is calculated based on the difference between the fair market value of the Company’s stock on the exercise date and the exercise price.

The following table summarizes restricted stock and restricted stock units activities for the periods indicated:

				Weighted-
				Average
				Grant-Date
	Shares			Fair Value
Unvested at January 31, 2018		2,103,281		$	56.45
Granted		1,367,751			40.03
Vested		(994,500	)		53.27
Forfeited		(81,016	)		53.57
Unvested at January 31, 2019		2,395,516			48.49
Granted		1,329,288			54.54
Vested		(1,012,581	)		51.24
Forfeited		(94,957	)		54.26
Unvested at January 31, 2020		2,617,266			50.30
Granted		1,499,203			53.45
Vested		(1,162,883	)		50.53
Forfeited		(81,785	)		54.48
Unvested at January 31, 2021		2,871,801		$	51.73

Total fair value as of the respective vesting dates of restricted stock and restricted stock units vested for the fiscal years ended January 31, 2021, 2020 and 2019 was approximately $69.0 million, $52.1 million, and $42.9 million, respectively. As of January 31, 2021, the aggregate intrinsic value of unvested restricted stock units was $271.0 million.

Net Loss Per Ordinary Share

12 Months Ended

Jan. 31, 2021

Earnings Per Share [Abstract]

Net Loss Per Ordinary Share

12. Net Loss Per Ordinary Share

The following table sets forth the computation of basic and diluted net loss per ordinary share for the periods indicated:

	Year Ended January 31,
	2021			2020			2019
	(in thousands, except share and per share data)
Numerator:
Net loss	$	(59,786	)	$	(44,792	)	$	(30,447	)
Denominator:
Weighted-average ordinary shares - basic		34,679,717			33,083,562			32,713,606
Weighted-average ordinary shares - diluted		34,679,717			33,083,562			32,713,606
Net loss per ordinary share:
Basic	$	(1.72	)	$	(1.35	)	$	(0.93	)
Diluted	$	(1.72	)	$	(1.35	)	$	(0.93	)

The following weighted-average potentially dilutive securities were excluded from the computation of diluted net loss per ordinary share as their effect would have been antidilutive:

	Year Ended January 31,
	2021		2020		2019
Options to purchase ordinary shares		660,025		913,678		1,190,607
Restricted stock and restricted stock units		1,440,176		1,139,269		1,522,903
Employee stock purchase plan		27,789		8,530		26,831
		2,127,990		2,061,477		2,740,341

Income Taxes

12 Months Ended

Jan. 31, 2021

Income Tax Disclosure [Abstract]

Income Taxes

13. Income Taxes

Loss before income taxes consisted of the following for the periods indicated:

	Year Ended January 31,
	2021			2020			2019
	(in thousands)
U.S. operations	$	8		$	845		$	1,381
Non-U.S. operations		(57,311	)		(42,473	)		(35,933	)
Loss before income taxes	$	(57,303	)	$	(41,628	)	$	(34,552	)

Income tax provision (benefit) consisted of the following for the periods indicated:

	Year Ended January 31,
	2021			2020			2019
	(in thousands)
Current:
U.S. federal tax	$	1,705		$	1,440		$	1,290
U.S. state taxes		256			3			2
Non-U.S. foreign taxes		1,019			1,540			1,561
		2,980			2,983			2,853
Deferred:
U.S. federal tax		(432	)		182			(7,077	)
U.S. state taxes		—			—			—
Non-U.S. foreign taxes		(65	)		(1	)		119
		(497	)		181			(6,958	)
Provision (benefit) for income taxes	$	2,483		$	3,164		$	(4,105	)

The Company consists of a Cayman Islands parent company with various foreign and U.S. Subsidiaries. Effective December 31, 2019, the Company has structured its activities to comply with the International Tax Co-Operation (Economic Substance) Law, 2018 in the Cayman Islands. As part of the new structure, the Company is the general partner of a Canadian limited partnership, the ultimate beneficial owner, and is allocated all of the earnings of the partnership. The primary jurisdiction where our foreign earnings are derived is the Cayman Islands, where the Company is domiciled. Under the current laws of the Cayman Islands, the Company is not subject to tax on its income. For purposes of the reconciliation between the provision (benefit) for income taxes at the statutory rate and the effective tax rate, a notional U.S. 21% rate is applied to pretax income (loss) as a result of the following for the periods indicated, respectively:

	Year Ended January 31,
	2021			2020			2019
	(in thousands)
Provision at U.S. notional statutory rate	$	(12,034	)	$	(8,742	)	$	(7,256	)
U.S. state taxes		212			3			2
Non-U.S. foreign tax differential		12,989			10,458			9,226
Stock-based compensation		4,943			4,172			4,715
U.S. R&D credit		(3,928	)		(3,109	)		(2,770	)
Valuation allowance		—			—			(7,990	)
Other		301			382			(32	)
Provision (benefit) for income taxes	$	2,483		$	3,164		$	(4,105	)

On December 22, 2017, the Tax Cuts and Jobs Act (the “Tax Act”) was enacted into law in the United States. The tax legislation contains several provisions that impacted the Company, including the reduction of the corporate income tax rate from 35% to 21%, acceleration of business asset expensing, and a reduction in the amount of executive pay that may qualify as a tax deduction, among others. The income tax benefit recorded for the fiscal year ended January 31, 2019 includes the impact of the Tax Act.

On March 27, 2020, the Coronavirus Aid, Relief, and Economic Security Act (“CARES Act”), P.L. 116-136, was passed into law, amending portions of certain relevant US tax laws. The CARES Act includes a number of federal income tax law changes, including, but not limited to: 1) permitting net operating loss carrybacks to offset 100% of taxable income for taxable years beginning before 2021, 2) accelerating alternative minimum tax credit refunds, 3) temporarily increasing the allowable business interest deduction from 30% to 50% of adjusted taxable income, and 4) providing a technical correction for depreciation related to qualified improvement property. The CARES Act also provides for an Employee Retention Credit, a fully refundable payroll tax credit for certain eligible employers, and the ability for all eligible employers to defer payment of the employer share of payroll taxes owed on wages paid for the period ending December 31, 2020. The Company evaluated the impact of the CARES Act and does not expect it will have a material impact on the Company’s condensed consolidated financial statements.

Temporary differences that gave rise to significant portions of the Company’s deferred tax assets and liabilities at January 31, 2021 and 2020 were as follows:

	As of January 31,
	2021			2020
	(in thousands)
Deferred tax assets:
Federal and state credits	$	24,394		$	21,275
Expenses not currently deductible		939			593
Operating lease liabilities		2,144			2,023
Stock-based compensation		3,349			3,203
Foreign deferred		184			132
Gross deferred tax assets		31,010			27,226
Valuation allowance		(17,962	)		(14,670	)
Total deferred tax assets	$	13,048		$	12,556
Deferred tax liabilities
Property and equipment		(1,443	)		(1,469	)
Operating lease assets		(1,978	)		(1,974	)
Net deferred tax assets	$	9,627		$	9,113

Tax valuation allowance for the periods indicated below were as follows:

							Deductions
					Additions		Charged to
	Balance at		Additional		Charged to		Expenses			Balance at
	Beginning of		Charged to		Other		or Other			End of
	Period		Expenses		Account		Accounts			Period
	(in thousands)
Tax Valuation Allowance
Year ended January 31, 2021	$	14,670		3,292		—		—		$	17,962
Year ended January 31, 2020	$	12,526		2,144		—		—		$	14,670
Year ended January 31, 2019	$	18,538		1,978		—		(7,990	)	$	12,526

The Company conducts its business in several countries and regions and is subject to taxation in those jurisdictions. The Company is incorporated in the Cayman Islands with foreign subsidiaries in the U.S., China, Taiwan, Italy and other foreign countries and regions. As such, the Company’s worldwide operating income is subject to varying tax rates and its effective tax rate is highly dependent upon the geographic distribution of its earnings or losses and the tax laws and regulations in each geographical region. Consequently, the Company has experienced lower effective tax rates as a substantial amount of its operations are conducted in lower-tax jurisdictions. If the Company’s operational structure was to change in such a manner that would increase the amount of operating income subject to taxation in higher-tax jurisdictions, or if the Company was to commence operations in jurisdictions assessing relatively higher tax rates, its effective tax rate could fluctuate significantly on a quarterly basis and/or be adversely affected. Dividend distributions received from the Company’s U.S. subsidiary and certain other foreign subsidiaries may be subject to local country withholding taxes when, and if, distributed. Deferred tax liabilities have not been recorded on unremitted earnings of certain subsidiaries because management’s intent is to indefinitely reinvest any undistributed earnings in those subsidiaries. If dividend distributions from those subsidiaries were to occur, the liability as of January 31, 2021 would be $12.4 million. Cumulative undistributed earnings of foreign subsidiaries for which no deferred taxes have been provided approximated $85.1 million at January 31, 2021.

As of January 31, 2021 and 2020, the Company had deferred tax assets (net of deferred tax liabilities) before valuation allowance, of $27.6 million and $23.8 million, respectively. The Company assesses whether a valuation allowance should be established against its deferred tax assets based on the consideration of all available evidence, using a “more likely than not” standard.

The Company has $2.7 million of California net operating loss carryforwards as of January 31, 2021. The California net operating loss carryforwards begin to expire in fiscal year 2036, if not utilized. For financial statement purposes these carry forwards are offset by uncertain tax positions.

The Company also has Federal and California state research and development credit carryforwards of approximately $22.4 million and $27.1 million, respectively, at January 31, 2021. The Federal credits begin to expire in fiscal year 2035. The California credits can be carried forward indefinitely.

The Company reports its U.S. state deferred tax assets and related valuation allowance, net of the U.S federal tax rate of 21%. As of January 31, 2021, the Company has recorded a valuation allowance of $18.0 million against all of its U.S. state deferred tax assets due to uncertainty regarding the future utilization of these deferred tax assets.

Utilization of the research credit carryforwards may be subject to an annual limitation due to the ownership percentage change limitations as defined by the U.S. Internal Revenue Code Section 382, as amended, and similar state provisions. The annual limitation may result in the expiration of the U.S. Federal and state research credit carryforwards before utilization. The Company does not expect any tax credit carryforwards to expire as a result of a Section 382 limitation.

The Company applies the provisions of FASB’s guidance on accounting for uncertainty in income taxes. As of January 31, 2021, the Company had approximately $27.3 million in unrecognized tax benefits, $21.4 million of which would affect the Company’s effective tax rate if recognized. The remainder of the unrecognized tax benefits would not affect the effective tax rate due to the full valuation recorded for state deferred tax assets. The following table sets forth a reconciliation of the beginning and ending amount of unrecognized tax benefits:

	Year Ended January 31,
	2021			2020			2019
	(in thousands)
Beginning balance:	$	42,695		$	37,531		$	34,117
Additions based on tax positions related to the current year		3,360			4,964			3,922
Additions for tax positions of prior years		16			252			109
Reductions for tax positions in prior years		(12,483	)		—			(552	)
Settlements for prior periods		(6,087	)		—			—
Lapse of applicable statute of limitations		(245	)		(52	)		(65	)
Ending balance:	$	27,256		$	42,695		$	37,531

The Company classified $7.9 million and $7.5 million of income tax liabilities as other long-term liabilities as of January 31, 2021 and 2020, respectively, because payment of cash or settlement is not anticipated within one year from the balance sheet date.

The Company recognizes interest and penalties related to uncertain tax positions as a component of income tax expense. The Company recorded $283,000 and $358,000 and $263,000 of interest expense and penalties related to uncertain tax positions for the fiscal years ended January 31, 2021, 2020 and 2019, respectively. The Company recorded noncurrent liabilities of $1,043,000 and $760,000 related to interest and penalties for uncertain tax positions at January 31, 2021 and 2020, respectively.

The primary jurisdiction where our foreign earnings are derived is the Cayman Islands, where the Company is domiciled. The Company files income tax returns in the U.S. federal jurisdiction as well as many U.S. state and foreign jurisdictions. The Internal Revenue Service is currently examining the Company’s U.S. federal income tax return for the fiscal year ended January 31, 2017. The tax years 2013 to 2020 remain open to examination by U.S. federal tax authorities. The tax years 2009 to 2020 remain open to examination by U.S. state tax authorities. The tax years 2015 to 2020 remain open to examination by foreign tax authorities. Fiscal years outside of the normal statute of limitations remain open to audit by tax authorities due to tax attributes generated in those earlier years, which have been carried forward and may be audited in subsequent years when utilized.

The Company regularly assesses the likelihood of adverse outcomes resulting from potential tax examinations to determine the adequacy of its provision for income taxes. These assessments can require considerable estimates and judgments. During the fiscal year ended January 31, 2021, the gross amount of unrecognized tax benefits decreased by $15.4 million to $27.3 million. The decrease was primarily due to changes to our uncertain tax positions from adjustments arising from tax return filings based on our ongoing exam with the Internal Revenue Service. If the estimates of income tax liabilities prove to be less than the ultimate assessment, then a further charge to expense could be required. If events occur, and the payment of these amounts ultimately proves to be unnecessary, the reversal of the liabilities could result in tax benefits being recognized in the period in which the Company determines the liabilities are no longer necessary. The Company does not anticipate significant changes to its uncertain tax positions during the next twelve months.

As of January 31, 2021, the Company’s long-term income taxes payable, including estimated interest and penalties, was approximately $9.0 million. The Company was unable to make a reasonably reliable estimate of the timing of payments in individual years due to uncertainties in the timing of tax audits, if any, or their outcomes.

On July 27, 2015, the United States Tax Court issued a decision (“Tax Court Decision”) in Altera Corp. v. Commissioner, which concluded that related parties in a cost sharing arrangement are not required to share expenses related to share-based compensation. The Tax Court Decision was appealed by the Commissioner to the Ninth Circuit Court of Appeals (“Ninth Circuit”). On June 7, 2019, the Ninth Circuit issued an opinion that reversed the Tax Court Decision. On July 22, 2019, the taxpayer requested a rehearing before the full Ninth Circuit and the request was denied on November 12, 2019. On February 10, 2020, the taxpayer filed a petition to appeal the decision with the Supreme Court of the United States which was denied on June 22, 2020. The denial of the request by the Supreme Court did not have a material impact to the Company’s provision for income taxes.

- Definition

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

+ References + Details

Commitments and Contingencies

12 Months Ended

Jan. 31, 2021

Commitments And Contingencies Disclosure [Abstract]

Commitments and Contingencies

14. Commitments and Contingencies

Contract Manufacturer Commitments

The Company’s components and products are procured and built by independent contract manufacturers based on sales forecasts. These forecasts include estimates of future demand, historical trends, analysis of sales and marketing activities, and adjustment of overall market conditions. The Company regularly issues purchase orders to independent contract manufacturers which are cancelable only upon the agreement between the Company and the third-party. As of January 31, 2021 and 2020, total manufacturing purchase commitments were approximately $48.2 million and $35.9 million, respectively.

Indemnification

The Company, from time to time, in the normal course of business, indemnifies certain vendors with whom it enters into contractual relationships. The Company has agreed to hold the other party harmless against third-party claims in connection with the Company’s future products. The Company also indemnifies certain customers against third-party claims related to certain intellectual property matters. It is not possible to determine the maximum potential amount of liability under these indemnification obligations due to the limited history of prior indemnification claims and the unique facts and circumstances that are likely to be involved in each particular claim. The Company has not made payments under these obligations and no liabilities have been recorded for these obligations on the consolidated balance sheets as of January 31, 2021 and 2020, respectively.

Segment Reporting

12 Months Ended

Jan. 31, 2021

Segment Reporting [Abstract]

Segment Reporting

15. Segment Reporting

The Company operates in one reportable segment related to the development and sales of low-power, high-definition (HD), Ultra HD video compression, image processing and computer vision solutions. The Chief Executive Officer of the Company has been identified as the Chief Operating Decision Maker (the “CODM”) and manages the Company’s operations as a whole. For the purpose of evaluating financial performance and allocating resources, the CODM reviews financial information presented on a consolidated basis accompanied by information by customer and geographic region.

Geographic Revenue

The following table sets forth the Company’s revenue by geographic region based on bill-to location for the periods indicated.

	Year Ended January 31,
	2021		2020		2019
	(in thousands)
Taiwan	$	139,327	$	137,946	$	132,199
Asia Pacific		57,270		66,867		66,981
Europe		9,415		11,134		18,244
North America other than United States		10,304		8,402		7,028
United States		6,674		4,383		3,316
Total revenue	$	222,990	$	228,732	$	227,768

Substantially all of the Company’s property and equipment were located in the United States, Asia Pacific region and Europe. As of January 31, 2021, the net amount of these fixed assets located in these regions was approximate $2.0 million, $2.4 million and $1.1 million, respectively. As of January 31, 2020, the net amount of these fixed assets located in these regions was approximately $1.7 million, $2.8million and $1.1 million, respectively.

Major Customers

The customers representing 10% or more of revenue and accounts receivable for the fiscal year ended January 31, 2021 were Wintech and Chicony which accounted for approximately 63% and 16% of total revenue, respectively. For the fiscal year ended January 31, 2020, the customers representing 10% or more of revenue and accounts receivable were Wintech and Chicony which accounted for approximately 60% and 18% of total revenue, respectively. For the fiscal year ended January 31, 2019, the customers representing 10% or more of revenue and accounts receivables were Wintech and Chicony which accounted for approximately 58% and 16% of total revenue, respectively. Accounts receivable from Wintech and Chicony accounted for approximately $12.0 million and $8.6 million as of January 31, 2021, respectively. Accounts receivable from Wintech and Chicony accounted for approximately $3.8 million and $10.8 million as of January 31, 2020, respectively.

- Definition

The entire disclosure for reporting segments including data and tables. Reportable segments include those that meet any of the following quantitative thresholds a) it's reported revenue, including sales to external customers and intersegment sales or transfers is 10 percent or more of the combined revenue, internal and external, of all operating segments b) the absolute amount of its reported profit or loss is 10 percent or more of the greater, in absolute amount of 1) the combined reported profit of all operating segments that did not report a loss or 2) the combined reported loss of all operating segments that did report a loss c) its assets are 10 percent or more of the combined assets of all operating segments.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 31
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8924-108599

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 34
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8981-108599

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 21
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8721-108599

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
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-Paragraph 40
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e9031-108599

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8933-108599

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8933-108599

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 26
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8844-108599

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 41
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e9038-108599

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8933-108599

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 22
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8736-108599

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 42
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e9054-108599

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8657-108599

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 21
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8721-108599

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-URI http://asc.fasb.org/topic&trid=2134510

+ Details

Organization and Summary of Significant Accounting Policies (Policies)

12 Months Ended

Jan. 31, 2021

Accounting Policies [Abstract]

Organization

The Company sells its solutions to leading original design manufacturers, or ODMs, and original equipment manufacturers, or OEMs, globally.

Basis of Consolidation

Use of Estimates

Concentration of Risk

Foreign Currency Transactions

Fair Value of Financial Instruments

Cash Equivalents and Marketable Debt Securities

Restricted Cash

	As of January 31,
	2021		2020		2019
	(in thousands)
Cash and cash equivalents	$	241,274	$	231,403	$	194,047
Restricted cash		10		9		11
Total as presented in the consolidated statements of cash flows	$	241,284	$	231,412	$	194,058

Trade Accounts Receivable and Allowance for Credit Losses

Inventories

Property and Equipment

Noncancelable Internal-Use Software License

Leases

Goodwill and In-Process Research and Development

Impairment of Long-Lived Assets Including Goodwill and Other Acquired Intangible Assets

Equity Investment

Revenue Recognition

Cost of Revenue

Research and Development

Selling, General and Administrative

Stock-Based Compensation

Income Taxes

Net Income (Loss) Per Ordinary Share

Comprehensive Income (Loss)

Comprehensive income (loss) includes unrealized gains or losses from available-for-sale securities that are excluded from net income (loss).

Recent Accounting Pronouncements

Organization and Summary of Significant Accounting Policies (Tables)

12 Months Ended

Jan. 31, 2021

Accounting Policies [Abstract]

Schedule of Cash, Cash Equivalents and Restricted Cash

The following table presents cash, cash equivalents and restricted cash reported on the consolidated balance sheets, and the sums are presented on the consolidated statements of cash flows:

	As of January 31,
	2021		2020		2019
	(in thousands)
Cash and cash equivalents	$	241,274	$	231,403	$	194,047
Restricted cash		10		9		11
Total as presented in the consolidated statements of cash flows	$	241,284	$	231,412	$	194,058

Financial Instruments and Fair Value (Tables)

12 Months Ended

Jan. 31, 2021

Investments All Other Investments [Abstract]

Schedule of Available-for-Sale Securities at Fair Value

All of the investments are classified as available-for-sale securities and reported at fair value in the consolidated balance sheets as follows:

	As of January 31, 2021
	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
	(in thousands)
Money market funds	$	171	$	—	$	—		$	171
Commercial paper		66,181		—		—			66,181
Corporate bonds		102,108		980		(7	)		103,081
Asset-backed securities		15,740		164		—			15,904
U.S. government securities		29,383		82		—			29,465
Total cash equivalents and marketable debt securities	$	213,583	$	1,226	$	(7	)	$	214,802

	As of January 31, 2020
	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
	(in thousands)
Money market funds	$	8,284	$	—	$	—		$	8,284
Commercial paper		63,390		—		—			63,390
Corporate bonds		95,053		653		—			95,706
Asset-backed securities		23,062		69		(2	)		23,129
U.S. government securities		20,524		48		—			20,572
Total cash equivalents and marketable debt securities	$	210,313	$	770	$	(2	)	$	211,081

Schedule of Cash Equivalents and Marketable Debt Securities

As of January 31, 2021, there were no debt securities with unrealized losses for more than twelve months.

	As of
	January 31, 2021		January 31, 2020
	(in thousands)
Included in cash equivalents	$	15,368	$	37,736
Included in marketable debt securities		199,434		173,345
Total cash equivalents and marketable debt securities	$	214,802	$	211,081

Summary of Contractual Maturities of Investments

The contractual maturities of the investments at January 31, 2021 and 2020 were as follows:

	As of
	January 31, 2021		January 31, 2020
	(in thousands)
Due within one year	$	135,899	$	146,267
Due within one to three years		78,903		64,814
Total cash equivalents and marketable debt securities	$	214,802	$	211,081

Schedule of Fair Value of Financial Instruments Measured on Recurring Basis

The following tables present the fair value of the financial instruments measured on a recurring basis as of January 31, 2021 and 2020, respectively:

	As of January 31, 2021
	Total		Level 1		Level 2		Level 3
	(in thousands)
Money market funds	$	171	$	171
Commercial paper		66,181				66,181
Corporate bonds		103,081				103,081
Asset-backed securities		15,904				15,904
U.S. government securities		29,465				29,465
Total cash equivalents and marketable debt securities	$	214,802	$	171	$	214,631	$	—

	As of January 31, 2020
	Total		Level 1		Level 2		Level 3
	(in thousands)
Money market funds	$	8,284	$	8,284	$	—	$	—
Commercial paper		63,390		—		63,390		—
Corporate bonds		95,706		—		95,706		—
Asset-backed securities		23,129		—		23,129		—
U.S. government securities		20,572		—		20,572		—
Total cash equivalents and marketable debt securities	$	211,081	$	8,284	$	202,797	$	—

Inventories (Tables)

12 Months Ended

Jan. 31, 2021

Inventory Disclosure [Abstract]

Schedule of Inventory

Inventories at January 31, 2021 and 2020 consisted of the following:

	As of January 31,
	2021		2020
	(in thousands)
Work-in-progress	$	18,219	$	10,133
Finished goods		7,862		12,838
Total	$	26,081	$	22,971

Property and Equipment, Net (Tables)

12 Months Ended

Jan. 31, 2021

Property Plant And Equipment [Abstract]

Schedule of Property and Equipment

Property and equipment at January 31, 2021 and 2020 consisted of the following:

	As of January 31,
	2021			2020
	(in thousands)
Computer equipment and software	$	11,525		$	10,282
Machinery and equipment		6,946			6,317
Furniture and fixtures		969			969
Leasehold improvements		2,237			2,356
Construction in progress		331			63
		22,008			19,987
Less: accumulated depreciation and amortization		(16,478	)		(14,373	)
Total property and equipment, net	$	5,530		$	5,614

Intangible Assets, Net (Tables)

12 Months Ended

Jan. 31, 2021

Goodwill And Intangible Assets Disclosure [Abstract]

Summary of Carrying Amounts of Intangible Assets

The carrying amounts of intangible assets as of January 31, 2021 and 2020 were as follows:

	As of January 31, 2021							As of January 31, 2020
	Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount		Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount
	(in thousands)
In-process research and development	$	4,100	$	—		$	4,100	$	4,100	$	—		$	4,100
Software licenses		21,043		(6,440	)		14,603		27,203		(13,477	)		13,726
Total acquired intangible assets	$	25,143	$	(6,440	)	$	18,703	$	31,303	$	(13,477	)	$	17,826

Summary of Expected Annual Amortization Expense Related to Software Licenses

The expected annual amortization expense related to these software licenses as of January 31, 2021 is as follows:

	As of
	January 31, 2021
Fiscal Year	(in thousands)
2022	$	5,926
2023		6,269
2024		2,408
2025		—
2026		—
Thereafter		—
Total future amortization expenses:	$	14,603

Accrued and Other Current Liabilities (Tables)

12 Months Ended

Jan. 31, 2021

Payables And Accruals [Abstract]

Schedule of Accrued and Other Current Liabilities

Accrued and other current liabilities at January 31, 2021 and 2020 consisted of the following:

	As of January 31,
	2021		2020
	(in thousands)
Accrued employee compensation	$	18,105	$	16,874
Accrued rebates		391		54
Accrued product development costs		21,157		10,885
Software license liabilities, current		5,582		4,388
Other accrued liabilities		2,891		2,769
Total accrued and other current liabilities	$	48,126	$	34,970

Leases (Tables)

12 Months Ended

Jan. 31, 2021

Leases [Abstract]

Schedule of Supplemental Cash Flow Information Related to Leases

Supplemental cash flow information related to leases is as follows:

	Year Ended
	January 31, 2021
	(in thousands)
Cash paid for operating leases included in operating cash flows	$	2,416
Supplemental non-cash information related to lease liabilities arising from obtaining right-of-use assets	$	348
Leased assets obtained in exchange for operating lease liabilities arising from lease modifications	$	2,440

Schedule of Future Minimum Lease Payments for Lease Liabilities Excluding Parma Lease

	As of
	January 31, 2021
Fiscal Year	(in thousands)
2022	$	3,217
2023		2,315
2024		2,095
2025		2,153
2026		1,171
Thereafter		277
Total future annual minimum lease payments		11,228
Less: interest		(792	)
Total lease liabilities	$	10,436

Other Long-Term Liabilities (Tables)

12 Months Ended

Jan. 31, 2021

Other Liabilities Disclosure [Abstract]

Schedule of Other Long-Term Liabilities

Other long-term liabilities at January 31, 2021 and 2020 consisted of the following:

	As of January 31,
	2021		2020
	(in thousands)
Unrecognized tax benefits, including interest	$	8,966	$	8,261
Deferred tax liabilities, non-current		1,288		1,288
Software license liabilities, non-current		6,259		8,159
Other long-term liabilities		299		68
Total other long-term liabilities	$	16,812	$	17,776

Capital Stock (Tables)

12 Months Ended

Jan. 31, 2021

Equity [Abstract]

Schedule of Ordinary Shares Reserved for Future Issuance under EIP and ESPP

As of January 31, 2021 and January 31, 2020, the following ordinary shares were reserved for future issuance under the EIP and ESPP:

	As of January 31,
	2021		2020
Shares reserved for options, restricted stock and restricted stock units		5,981,741		6,045,108
Shares reserved for employee stock purchase plan		2,299,143		2,059,504

Employee Benefits and Stock-based Compensation (Tables)

12 Months Ended

Jan. 31, 2021

Postemployment Benefits [Abstract]

Classification of Stock-based Compensation

The following table presents the classification of stock-based compensation for the periods indicated:

	Year Ended January 31,
	2021		2020		2019
	(in thousands)
Stock-based compensation:
Cost of revenue	$	1,328	$	1,184	$	1,261
Research and development		42,903		41,842		37,432
Selling, general and administrative		25,903		23,845		22,119
Total stock-based compensation	$	70,134	$	66,871	$	60,812

Weighted-Average Assumptions Used to Estimate Fair Value

The following table sets forth the weighted-average assumptions used to estimate the fair value of the stock options and employee stock purchase plan awards for the periods indicated:

	Year Ended January 31,
	2021			2020			2019
Stock Options:
Volatility		52	%		52	%		54	%
Risk-free interest rate		0.52	%		1.82	%		2.77	%
Expected term (years)		5.78			6.01			5.41
Dividend yield		0	%		0	%		0	%
Employee stock purchase plan awards:
Volatility		59	%		47	%		45	%
Risk-free interest rate		0.21	%		2.23	%		2.15	%
Expected term (years)		0.5			0.5			0.5
Dividend yield		0	%		0	%		0	%

Stock Option Activities

The following table summarizes stock option activities for the periods indicated:

	Option Outstanding
										Weighted-
								Total Intrinsic		Average
						Weighted-		Value of		Remaining		Aggregate
				Weighted-		Average		options		Contractual		Intrinsic
				Average		Grant-date		Exercised		Term		Value
	Shares			Exercise Price		Fair Value		(in thousands)		(in years)		(in thousands)
Outstanding at January 31, 2018		1,611,344		$	24.56
Granted		116,600			42.73	$	21.75
Exercised		(232,205	)		5.54			$	8,867
Forfeited		(20,974	)		53.50
Expired		(15,701	)		54.35
Outstanding at January 31, 2019		1,459,064			28.31
Granted		66,850			50.56	$	25.35
Exercised		(366,886	)		15.52			$	13,263
Forfeited		(14,931	)		46.29
Expired		(19,451	)		64.53
Outstanding at January 31, 2020		1,124,646			32.93
Granted		51,200			59.54	$	28.37
Exercised		(421,736	)		24.52			$	19,401
Forfeited		(11,618	)		46.69
Expired		(23,349	)		70.11
Outstanding at January 31, 2021		719,143		$	38.33					4.42		$	40,358
Exercisable at January 31, 2021		592,729		$	35.27						3.56	$	35,092

Restricted Stock and Restricted Stock Units Activities

The following table summarizes restricted stock and restricted stock units activities for the periods indicated:

				Weighted-
				Average
				Grant-Date
	Shares			Fair Value
Unvested at January 31, 2018		2,103,281		$	56.45
Granted		1,367,751			40.03
Vested		(994,500	)		53.27
Forfeited		(81,016	)		53.57
Unvested at January 31, 2019		2,395,516			48.49
Granted		1,329,288			54.54
Vested		(1,012,581	)		51.24
Forfeited		(94,957	)		54.26
Unvested at January 31, 2020		2,617,266			50.30
Granted		1,499,203			53.45
Vested		(1,162,883	)		50.53
Forfeited		(81,785	)		54.48
Unvested at January 31, 2021		2,871,801		$	51.73

Net Loss Per Ordinary Share (Tables)

12 Months Ended

Jan. 31, 2021

Earnings Per Share [Abstract]

Computation of Basic and Diluted Net Loss Per Ordinary Share

The following table sets forth the computation of basic and diluted net loss per ordinary share for the periods indicated:

	Year Ended January 31,
	2021			2020			2019
	(in thousands, except share and per share data)
Numerator:
Net loss	$	(59,786	)	$	(44,792	)	$	(30,447	)
Denominator:
Weighted-average ordinary shares - basic		34,679,717			33,083,562			32,713,606
Weighted-average ordinary shares - diluted		34,679,717			33,083,562			32,713,606
Net loss per ordinary share:
Basic	$	(1.72	)	$	(1.35	)	$	(0.93	)
Diluted	$	(1.72	)	$	(1.35	)	$	(0.93	)

Weighted-Average Potentially Dilutive Securities Excluded from Computation of Diluted Net Loss Per Ordinary Share

The following weighted-average potentially dilutive securities were excluded from the computation of diluted net loss per ordinary share as their effect would have been antidilutive:

	Year Ended January 31,
	2021		2020		2019
Options to purchase ordinary shares		660,025		913,678		1,190,607
Restricted stock and restricted stock units		1,440,176		1,139,269		1,522,903
Employee stock purchase plan		27,789		8,530		26,831
		2,127,990		2,061,477		2,740,341

Income Taxes (Tables)

12 Months Ended

Jan. 31, 2021

Income Tax Disclosure [Abstract]

Summary of Loss before Income Taxes

Loss before income taxes consisted of the following for the periods indicated:

	Year Ended January 31,
	2021			2020			2019
	(in thousands)
U.S. operations	$	8		$	845		$	1,381
Non-U.S. operations		(57,311	)		(42,473	)		(35,933	)
Loss before income taxes	$	(57,303	)	$	(41,628	)	$	(34,552	)

Schedule of Income Tax Provision (Benefit)

Income tax provision (benefit) consisted of the following for the periods indicated:

	Year Ended January 31,
	2021			2020			2019
	(in thousands)
Current:
U.S. federal tax	$	1,705		$	1,440		$	1,290
U.S. state taxes		256			3			2
Non-U.S. foreign taxes		1,019			1,540			1,561
		2,980			2,983			2,853
Deferred:
U.S. federal tax		(432	)		182			(7,077	)
U.S. state taxes		—			—			—
Non-U.S. foreign taxes		(65	)		(1	)		119
		(497	)		181			(6,958	)
Provision (benefit) for income taxes	$	2,483		$	3,164		$	(4,105	)

Schedule of Reconciliation Between the Provision (Benefit) for Income Taxes at the Statutory Rate and the Effective Tax Rate

For purposes of the reconciliation between the provision (benefit) for income taxes at the statutory rate and the effective tax rate, a notional U.S. 21% rate is applied to pretax income (loss) as a result of the following for the periods indicated, respectively:

	Year Ended January 31,
	2021			2020			2019
	(in thousands)
Provision at U.S. notional statutory rate	$	(12,034	)	$	(8,742	)	$	(7,256	)
U.S. state taxes		212			3			2
Non-U.S. foreign tax differential		12,989			10,458			9,226
Stock-based compensation		4,943			4,172			4,715
U.S. R&D credit		(3,928	)		(3,109	)		(2,770	)
Valuation allowance		—			—			(7,990	)
Other		301			382			(32	)
Provision (benefit) for income taxes	$	2,483		$	3,164		$	(4,105	)

Schedule of Deferred Tax Assets and Liabilities

Temporary differences that gave rise to significant portions of the Company’s deferred tax assets and liabilities at January 31, 2021 and 2020 were as follows:

	As of January 31,
	2021			2020
	(in thousands)
Deferred tax assets:
Federal and state credits	$	24,394		$	21,275
Expenses not currently deductible		939			593
Operating lease liabilities		2,144			2,023
Stock-based compensation		3,349			3,203
Foreign deferred		184			132
Gross deferred tax assets		31,010			27,226
Valuation allowance		(17,962	)		(14,670	)
Total deferred tax assets	$	13,048		$	12,556
Deferred tax liabilities
Property and equipment		(1,443	)		(1,469	)
Operating lease assets		(1,978	)		(1,974	)
Net deferred tax assets	$	9,627		$	9,113

Summary of Tax Valuation Allowance

Tax valuation allowance for the periods indicated below were as follows:

							Deductions
					Additions		Charged to
	Balance at		Additional		Charged to		Expenses			Balance at
	Beginning of		Charged to		Other		or Other			End of
	Period		Expenses		Account		Accounts			Period
	(in thousands)
Tax Valuation Allowance
Year ended January 31, 2021	$	14,670		3,292		—		—		$	17,962
Year ended January 31, 2020	$	12,526		2,144		—		—		$	14,670
Year ended January 31, 2019	$	18,538		1,978		—		(7,990	)	$	12,526

Schedule of Reconciliation of Beginning and Ending Amount of Unrecognized Tax Benefits

The following table sets forth a reconciliation of the beginning and ending amount of unrecognized tax benefits:

	Year Ended January 31,
	2021			2020			2019
	(in thousands)
Beginning balance:	$	42,695		$	37,531		$	34,117
Additions based on tax positions related to the current year		3,360			4,964			3,922
Additions for tax positions of prior years		16			252			109
Reductions for tax positions in prior years		(12,483	)		—			(552	)
Settlements for prior periods		(6,087	)		—			—
Lapse of applicable statute of limitations		(245	)		(52	)		(65	)
Ending balance:	$	27,256		$	42,695		$	37,531

Segment Reporting (Tables)

12 Months Ended

Jan. 31, 2021

Segment Reporting [Abstract]

Company's Revenue by Geographic Region Based on Bill-to Location

The following table sets forth the Company’s revenue by geographic region based on bill-to location for the periods indicated.

	Year Ended January 31,
	2021		2020		2019
	(in thousands)
Taiwan	$	139,327	$	137,946	$	132,199
Asia Pacific		57,270		66,867		66,981
Europe		9,415		11,134		18,244
North America other than United States		10,304		8,402		7,028
United States		6,674		4,383		3,316
Total revenue	$	222,990	$	228,732	$	227,768

Organization and Summary of Significant Accounting Policies - Schedule of Cash, Cash Equivalents and Restricted Cash (Detail) - USD ($) $ in Thousands	Jan. 31, 2021	Jan. 31, 2020	Jan. 31, 2019	Jan. 31, 2018
Cash And Cash Equivalents [Abstract]
Cash and cash equivalents	$ 241,274	$ 231,403	$ 194,047
Restricted cash	10	9	11
Total as presented in the consolidated statements of cash flows	$ 241,284	$ 231,412	$ 194,058	$ 346,681

Organization and Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)	12 Months Ended
	Jan. 31, 2021	Jan. 31, 2020	Jan. 31, 2019
Summary Of Significant Accounting Policies [Line Items]
Material inventory losses recognized	$ 0	$ 0	$ 0
Accumulated amortization of intangible asset	6,440,000	13,477,000
Impairment of long-lived assets	0
Goodwill impairment	0	$ 0	$ 0
Impairment losses on investment	$ 0
Expected dividend yield	0.00%	0.00%	0.00%
Prepaid Expenses and Other Current Assets [Member]
Summary Of Significant Accounting Policies [Line Items]
Grants recorded	$ 1,400,000
Other Non-current Assets [Member]
Summary Of Significant Accounting Policies [Line Items]
Grants recorded	2,000,000.0
IPR&D [Member]
Summary Of Significant Accounting Policies [Line Items]
Accumulated amortization of intangible asset	$ 0	$ 0

Financial Instruments and Fair Value - Schedule of Available-for-Sale Securities at Fair Value (Detail) - USD ($) $ in Thousands	Jan. 31, 2021	Jan. 31, 2020
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 213,583	$ 210,313
Unrealized Gains	1,226	770
Unrealized Losses	(7)	(2)
Fair Value	214,802	211,081
Money market funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	171	8,284
Unrealized Gains	0	0
Unrealized Losses	0	0
Fair Value	171	8,284
Commercial paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	66,181	63,390
Unrealized Gains	0	0
Unrealized Losses	0	0
Fair Value	66,181	63,390
Corporate bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	102,108	95,053
Unrealized Gains	980	653
Unrealized Losses	(7)	0
Fair Value	103,081	95,706
Asset-backed securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	15,740	23,062
Unrealized Gains	164	69
Unrealized Losses	0	(2)
Fair Value	15,904	23,129
U.S. government securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	29,383	20,524
Unrealized Gains	82	48
Unrealized Losses	0	0
Fair Value	$ 29,465	$ 20,572

Financial Instruments and Fair Value - Additional Information (Detail)	Jan. 31, 2021 Security
Investments Debt And Equity Securities [Abstract]
Number of debt securities with unrealized losses for more than twelve months	0

Financial Instruments and Fair Value - Schedule of Cash Equivalents and Marketable Debt Securities (Detail) - USD ($) $ in Thousands	Jan. 31, 2021	Jan. 31, 2020
Schedule of Available-for-sale Securities [Line Items]
Total cash equivalents and marketable debt securities	$ 214,802	$ 211,081
Included in cash equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Total cash equivalents and marketable debt securities	15,368	37,736
Included in marketable debt securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Total cash equivalents and marketable debt securities	$ 199,434	$ 173,345

Financial Instruments and Fair Value - Summary of Contractual Maturities of Investments (Detail) - USD ($) $ in Thousands	Jan. 31, 2021	Jan. 31, 2020
Available For Sale Securities Debt Maturities Fair Value [Abstract]
Due within one year	$ 135,899	$ 146,267
Due within one to three years	78,903	64,814
Total cash equivalents and marketable debt securities	$ 214,802	$ 211,081

Inventories - Schedule of Inventory (Detail) - USD ($) $ in Thousands	Jan. 31, 2021	Jan. 31, 2020
Inventory Disclosure [Abstract]
Work-in-progress	$ 18,219	$ 10,133
Finished goods	7,862	12,838
Total	$ 26,081	$ 22,971

Property and Equipment, Net - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Jan. 31, 2021	Jan. 31, 2020	Jan. 31, 2019
Property Plant And Equipment [Abstract]
Depreciation of property and equipment	$ 2.6	$ 2.8	$ 2.6

Property and Equipment, Net - Schedule of Property and Equipment (Detail) - USD ($) $ in Thousands	Jan. 31, 2021	Jan. 31, 2020
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 22,008	$ 19,987
Less: accumulated depreciation and amortization	(16,478)	(14,373)
Total property and equipment, net	5,530	5,614
Computer equipment and software [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	11,525	10,282
Machinery and equipment [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	6,946	6,317
Furniture and fixtures [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	969	969
Leasehold improvements [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	2,237	2,356
Construction in progress [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 331	$ 63

Intangible Assets, Net - Additional Information (Detail) - USD ($)	12 Months Ended
	Jan. 31, 2021	Jan. 31, 2020	Jan. 31, 2019	Jun. 25, 2015
Finite Lived Intangible Assets [Line Items]
Intangible assets, net of amortization expense	$ 18,703,000	$ 17,826,000
Accumulated amortization of intangible asset	6,440,000	13,477,000
Liabilities associated with noncancelable internal-use software license at net present value, current	5,582,000	4,388,000
Liabilities associated with noncancelable internal-use software license at net present value, non-current	6,259,000	8,159,000
Impairment of intangible assets	0	0	$ 0
Vis Lab SRL [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets acquired				$ 4,100,000
IPR&D [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets, net of amortization expense	4,100,000	4,100,000
Accumulated amortization of intangible asset	0	0
IPR&D [Member] \| Vis Lab SRL [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets acquired				$ 4,100,000
Noncancelable software licenses [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets, net of amortization expense		14,600,000
Internal-use software licenses [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets, net of amortization expense	14,603,000	13,726,000
Accumulated amortization of intangible asset	6,440,000	13,477,000
Fully amortized software licenses retired	13,500,000
Amortization expense	$ 6,500,000	$ 5,900,000	$ 4,700,000

Intangible Assets, Net - Summary of Carrying Amounts of Intangible Assets (Detail) - USD ($)	Jan. 31, 2021	Jan. 31, 2020
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 25,143,000	$ 31,303,000
Accumulated Amortization	(6,440,000)	(13,477,000)
Net Carrying Amount	18,703,000	17,826,000
In-process research and development [Member]
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	4,100,000	4,100,000
Accumulated Amortization	0	0
Net Carrying Amount	4,100,000	4,100,000
Internal-use software license [Member]
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	21,043,000	27,203,000
Accumulated Amortization	(6,440,000)	(13,477,000)
Net Carrying Amount	$ 14,603,000	$ 13,726,000

Intangible Assets, Net - Summary of Expected Annual Amortization Expense Related to Software Licenses (Detail) - USD ($) $ in Thousands	Jan. 31, 2021	Jan. 31, 2020
Finite Lived Intangible Assets [Line Items]
Net Carrying Amount	$ 18,703	$ 17,826
Internal-use software license [Member]
Finite Lived Intangible Assets [Line Items]
2022	5,926
2023	6,269
2024	2,408
2025	0
2026	0
Thereafter	0
Net Carrying Amount	$ 14,603	$ 13,726

Goodwill - Additional Information (Detail) - USD ($)		12 Months Ended
Goodwill - Additional Information (Detail) - USD ($)	Jun. 25, 2015	Jan. 31, 2021	Jan. 31, 2020	Jan. 31, 2019
Finite Lived Intangible Assets [Line Items]
Goodwill		$ 26,601,000	$ 26,601,000
Goodwill impairment		$ 0	$ 0	$ 0
Vis Lab SRL [Member]
Finite Lived Intangible Assets [Line Items]
Business acquisition date	Jun. 25, 2015
Cash paid for business acquisition	$ 30,000,000.0
Goodwill	25,300,000
Intangible assets acquired	4,100,000
Net assets acquired	600,000
Deferred tax liabilities, intangible assets	$ 1,300,000

Accrued and Other Current Liabilities - Schedule of Accrued and Other Current Liabilities (Detail) - USD ($) $ in Thousands	Jan. 31, 2021	Jan. 31, 2020
Payables And Accruals [Abstract]
Accrued employee compensation	$ 18,105	$ 16,874
Accrued rebates	391	54
Accrued product development costs	21,157	10,885
Software license liabilities, current	5,582	4,388
Other accrued liabilities	2,891	2,769
Total accrued and other current liabilities	$ 48,126	$ 34,970

Leases - Additional Information (Detail)	1 Months Ended	3 Months Ended	12 Months Ended			15 Months Ended
Leases - Additional Information (Detail)	Aug. 31, 2019 USD ($)	Jan. 31, 2021 USD ($)	Jan. 31, 2021 USD ($)	Jan. 31, 2020 USD ($) Contract	Jan. 31, 2019 USD ($)	Oct. 31, 2020
Lessee Lease Description [Line Items]
Operating leases, existence of options to extend			true	true
Operating lease expense under ASC 842			$ 3,000,000.0	$ 3,000,000.0
Operating lease expense under ASC 840					$ 4,600,000
Weighted-average remaining lease term – operating leases		4 years 3 months 25 days	4 years 3 months 25 days
Weighted-average discount rate – operating leases		4.11%	4.11%
Parma Lease [Member]
Lessee Lease Description [Line Items]
Future undiscounted cash payments		$ 0	$ 0
Renewed Contract [Member]
Lessee Lease Description [Line Items]
Operating lease number of renewed contracts \| Contract				2
An increase to operating lease right-of-use assets				$ 4,000,000.0
An increase to operating lease liabilities				$ 4,000,000.0
U.S. [Member] \| Additional Office Space [Member]
Lessee Lease Description [Line Items]
Lease term		56 months	56 months
Commencement date		Dec. 01, 2020				Jan. 01, 2021
Expiration date			Aug. 31, 2025
An increase to operating lease right-of-use assets			$ 1,600,000
An increase to operating lease liabilities			$ 1,600,000
U.S. [Member] \| Renewed Contract [Member]
Lessee Lease Description [Line Items]
Lease term				63 months
Commencement date				Jun. 01, 2020
Expiration date				Aug. 31, 2025
Shanghai [Member] \| Renewed Contract [Member]
Lessee Lease Description [Line Items]
Lease term				2 years
Commencement date				Dec. 01, 2019
Expiration date				Nov. 30, 2021
Italy [Member] \| Building [Member]
Lessee Lease Description [Line Items]
Lease term	35 years
Construction completion period	2 years
Italy [Member] \| Parma Lease [Member] \| Building [Member]
Lessee Lease Description [Line Items]
Future undiscounted cash payments	$ 2,200,000
Future undiscounted cash payments in construction phase	1,800,000
Future undiscounted cash payments, paid in remainder of lease term	$ 400,000

Leases - Schedule of Supplemental Cash Flow Information Related to Leases (Detail) $ in Thousands	12 Months Ended
	Jan. 31, 2021 USD ($)
Leases [Abstract]
Cash paid for operating leases included in operating cash flows	$ 2,416
Supplemental non-cash information related to lease liabilities arising from obtaining right-of-use assets	348
Leased assets obtained in exchange for operating lease liabilities arising from lease modifications	$ 2,440

Leases - Schedule of Future Minimum Lease Payments for Lease Liabilities Excluding Parma Lease (Detail) $ in Thousands	Jan. 31, 2021 USD ($)
Leases [Abstract]
2022	$ 3,217
2023	2,315
2024	2,095
2025	2,153
2026	1,171
Thereafter	277
Total future annual minimum lease payments	11,228
Less: interest	(792)
Total lease liabilities	$ 10,436

Other Long-Term Liabilities - Schedule of Other Long-Term Liabilities (Detail) - USD ($) $ in Thousands	Jan. 31, 2021	Jan. 31, 2020
Other Liabilities Disclosure [Abstract]
Unrecognized tax benefits, including interest	$ 8,966	$ 8,261
Deferred tax liabilities, non-current	1,288	1,288
Software license liabilities, non-current	6,259	8,159
Other long-term liabilities	299	68
Total other long-term liabilities	$ 16,812	$ 17,776

Capital Stock - Additional Information (Detail) - USD ($)					12 Months Ended			56 Months Ended
	May 29, 2020	Mar. 16, 2020	May 29, 2019	Jun. 30, 2016	Jan. 31, 2021	Jan. 31, 2020	Jan. 31, 2019	Jan. 31, 2021
Class Of Stock [Line Items]
Preference shares, shares authorized					20,000,000	20,000,000		20,000,000
Preference shares, par value					$ 0.00045	$ 0.00045		$ 0.00045
Preference shares, shares issued					0	0		0
Preference shares, shares outstanding					0	0		0
Amount authorized under stock repurchase program					$ 275,000,000.0			$ 275,000,000.0
Stock repurchase program, inception period				2016-06
Stock repurchased, shares								4,011,595
Stock repurchased during period, cash					$ 1,000,000	$ 0	$ 99,904,000	$ 175,800,000
Stock Repurchase Program $50.0 Million Authorization [Member]
Class Of Stock [Line Items]
Stock repurchase program, authorization date			May 29, 2019
Stock repurchase program, expiration date			Jun. 30, 2020		Jun. 30, 2021
Stock repurchased, shares		25,719
Stock repurchased during period, cash		$ 1,000,000.0
Amount available under stock repurchase program					$ 49,000,000.0			$ 49,000,000.0
Stock repurchase program, extended expiration period	12 months
Stock repurchase program, extended expiration date	Jun. 30, 2021
Stock Repurchase Program $50.0 Million Authorization [Member] \| Maximum [Member]
Class Of Stock [Line Items]
Amount authorized under stock repurchase program			$ 50,000,000.0

Capital Stock - Schedule of Ordinary Shares Reserved for Future Issuance under EIP and ESPP (Detail) - shares	Jan. 31, 2021	Jan. 31, 2020
EIP [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares reserved	5,981,741	6,045,108
ESPP [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares reserved	2,299,143	2,059,504

Employee Benefits and Stock-based Compensation - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		12 Months Ended
	Apr. 30, 2020	Apr. 30, 2019	Jan. 31, 2021	Jan. 31, 2020	Jan. 31, 2019	Jan. 31, 2018	Jan. 29, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Accrued share based compensation expense			$ 4.4
Closing price of stock							$ 94.36
EIP [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Voting power of all classes of company's shares			10.00%
Additional ordinary shares reserved for issuance	1,521,252	1,453,659
EIP [Member] \| Scenario, plan automatically increased by the lessor of [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Annual increase in ordinary shares for available for future issuance	3,500,000	3,500,000
Annual shares increase for future issuance by percentage under 2012 equity incentive plan	4.50%	4.50%
ESPP [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Purchase price of ordinary shares, percentage			85.00%		85.00%	85.00%
Percentage of salary contribution by employees			15.00%
Additional ordinary shares reserved for issuance	422,570	403,794
ESPP [Member] \| Scenario, plan automatically increased by the lessor of [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Annual increase in ordinary shares for available for future issuance	1,500,000	1,500,000
Annual shares increase for future issuance by percentage under 2012 employee stock purchase plan	1.25%	1.25%
Stock options [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total unrecognized compensation cost, stock options			$ 3.1
Weighted average recognition period			2 years 4 months 24 days
Stock options [Member] \| EIP [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Option's term of up to 10 years from grant date			10 years	10 years	10 years
Vesting schedule			vest 25% on the first anniversary service date of the grant and remainder vest ratably over the following 36 months.
Stock options [Member] \| Incentive stock options granted to 10% ownership [Member] \| Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Purchase price of ordinary shares, percentage			110.00%
Stock options [Member] \| Non statutory stock options and incentive stock options granted to less than 10% ownership [Member] \| Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Purchase price of ordinary shares, percentage			100.00%
Restricted Stock and Restricted Stock Units [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total fair value of vesting dates of restricted stock and restricted stock units vested			$ 69.0	$ 52.1	$ 42.9
Restricted Stock and Restricted Stock Units [Member] \| EIP [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting schedule			1/4th of the shares on the first anniversary service date of the grant and 1/16th of the shares vest every 3 months thereafter, so as to be 100% vested on the fourth anniversary of the vesting commencement date
Restricted stock units [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted average recognition period			2 years 4 months 6 days
Total unrecognized compensation cost, restricted stock units			$ 123.9
Aggregate intrinsic value of unvested restricted stock units			$ 271.0

Employee Benefits and Stock-based Compensation - Classification of Stock-based Compensation (Detail) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2021	Jan. 31, 2020	Jan. 31, 2019
Stock-based compensation:
Total stock-based compensation	$ 70,134	$ 66,871	$ 60,812
Cost of revenue [Member]
Stock-based compensation:
Total stock-based compensation	1,328	1,184	1,261
Research and development [Member]
Stock-based compensation:
Total stock-based compensation	42,903	41,842	37,432
Selling, general and administrative [Member]
Stock-based compensation:
Total stock-based compensation	$ 25,903	$ 23,845	$ 22,119

Employee Benefits and Stock-based Compensation - Weighted-Average Assumptions Used to Estimate Fair Value (Detail)	12 Months Ended
	Jan. 31, 2021	Jan. 31, 2020	Jan. 31, 2019
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Dividend yield	0.00%	0.00%	0.00%
Stock options [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Volatility	52.00%	52.00%	54.00%
Risk-free interest rate	0.52%	1.82%	2.77%
Expected term (years)	5 years 9 months 10 days	6 years 3 days	5 years 4 months 28 days
Dividend yield	0.00%	0.00%	0.00%
Employee stock purchase plan awards [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Volatility	59.00%	47.00%	45.00%
Risk-free interest rate	0.21%	2.23%	2.15%
Expected term (years)	6 months	6 months	6 months
Dividend yield	0.00%	0.00%	0.00%

Employee Benefits and Stock-based Compensation - Stock Option Activities (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Jan. 31, 2021	Jan. 31, 2020	Jan. 31, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Shares, Outstanding	1,124,646	1,459,064	1,611,344
Shares, Granted	51,200	66,850	116,600
Shares, Exercised	(421,736)	(366,886)	(232,205)
Shares, Forfeited	(11,618)	(14,931)	(20,974)
Shares, Expired	(23,349)	(19,451)	(15,701)
Shares, Outstanding	719,143	1,124,646	1,459,064
Shares, Exercisable	592,729
Weighted-Average Exercise Price, Outstanding	$ 32.93	$ 28.31	$ 24.56
Weighted-Average Exercise Price, Granted	59.54	50.56	42.73
Weighted-Average Exercise Price, Exercised	24.52	15.52	5.54
Weighted-Average Exercise Price, Forfeited	46.69	46.29	53.50
Weighted-Average Exercise Price, Expired	70.11	64.53	54.35
Weighted-Average Exercise Price, Outstanding	38.33	32.93	28.31
Weighted-Average Exercise Price, Exercisable	35.27
Weighted-Average Grant-date Fair Value, Granted	$ 28.37	$ 25.35	$ 21.75
Total Intrinsic Value of options Exercised	$ 19,401	$ 13,263	$ 8,867
Weighted-Average Remaining Contractual Term, Outstanding	4 years 5 months 1 day
Weighted-Average Remaining Contractual Term, Exercisable	3 years 6 months 21 days
Aggregate Intrinsic Value, Outstanding	$ 40,358
Aggregate Intrinsic Value, Exercisable	$ 35,092

Employee Benefits and Stock-based Compensation - Restricted Stock and Restricted Stock Units Activities (Detail) - Restricted stock and restricted stock units [Member] - $ / shares	12 Months Ended
	Jan. 31, 2021	Jan. 31, 2020	Jan. 31, 2019
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares, Unvested, beginning balance	2,617,266	2,395,516	2,103,281
Shares, Granted	1,499,203	1,329,288	1,367,751
Shares, Vested	(1,162,883)	(1,012,581)	(994,500)
Shares, Forfeited	(81,785)	(94,957)	(81,016)
Shares, Unvested, ending balance	2,871,801	2,617,266	2,395,516
Weighted-Average Grant-Date Fair Value, Unvested, beginning balance	$ 50.30	$ 48.49	$ 56.45
Weighted-Average Grant-Date Fair Value, Granted	53.45	54.54	40.03
Weighted-Average Grant-Date Fair Value, Vested	50.53	51.24	53.27
Weighted-Average Grant-Date Fair Value, Forfeited	54.48	54.26	53.57
Weighted-Average Grant-Date Fair Value, Unvested, ending balance	$ 51.73	$ 50.30	$ 48.49

Net Loss Per Ordinary Share - Computation of Basic and Diluted Net Loss Per Ordinary Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Jan. 31, 2021	Jan. 31, 2020	Jan. 31, 2019
Numerator:
Net loss	$ (59,786)	$ (44,792)	$ (30,447)
Denominator:
Weighted-average ordinary shares - basic	34,679,717	33,083,562	32,713,606
Weighted-average ordinary shares - diluted	34,679,717	33,083,562	32,713,606
Net loss per ordinary share:
Basic	$ (1.72)	$ (1.35)	$ (0.93)
Diluted	$ (1.72)	$ (1.35)	$ (0.93)

- Definition

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 3
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- Definition

The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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+ Details

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References

+ Details

Net Loss Per Ordinary Share - Weighted-Average Potentially Dilutive Securities Excluded from Computation of Diluted Net Loss Per Ordinary Share (Detail) - shares	12 Months Ended
	Jan. 31, 2021	Jan. 31, 2020	Jan. 31, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive shares excluded from computation of earnings per share	2,127,990	2,061,477	2,740,341
Options to purchase ordinary shares [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive shares excluded from computation of earnings per share	660,025	913,678	1,190,607
Restricted stock and restricted stock units [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive shares excluded from computation of earnings per share	1,440,176	1,139,269	1,522,903
Employee stock purchase plan awards [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive shares excluded from computation of earnings per share	27,789	8,530	26,831

Income Taxes - Summary of Loss before Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2021	Jan. 31, 2020	Jan. 31, 2019
Results Of Operations Income Before Income Taxes [Abstract]
U.S. operations	$ 8	$ 845	$ 1,381
Non-U.S. operations	(57,311)	(42,473)	(35,933)
Loss before income taxes	$ (57,303)	$ (41,628)	$ (34,552)

- Definition

Amount of income (loss) from continuing operations, including income (loss) from equity method investments, before deduction of income tax expense (benefit), and income (loss) attributable to noncontrolling interest.

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+ Details

Income Taxes - Schedule of Income Tax Provision (Benefit) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2021	Jan. 31, 2020	Jan. 31, 2019
Current:
U.S. federal tax	$ 1,705	$ 1,440	$ 1,290
U.S. state taxes	256	3	2
Non-U.S. foreign taxes	1,019	1,540	1,561
Current income tax provision	2,980	2,983	2,853
Deferred:
U.S. federal tax	(432)	182	(7,077)
U.S. state taxes	0	0	0
Non-U.S. foreign taxes	(65)	(1)	119
Deferred income tax provision	(497)	181	(6,958)
Provision (benefit) for income taxes	$ 2,483	$ 3,164	$ (4,105)

Income Taxes - Additional Information (Detail) - USD ($)	11 Months Ended	12 Months Ended
	Dec. 31, 2017	Jan. 31, 2021	Jan. 31, 2020	Jan. 31, 2019	Jan. 31, 2018
Income Taxes [Line Items]
Statutory tax rate	35.00%	21.00%	21.00%	21.00%
Deferred tax liabilities, not recognized		$ 12,400,000
Cumulative undistributed earnings of foreign subsidiaries		85,100,000
Gross deferred tax assets, net of deferred tax liabilities before valuation allowance		27,600,000	$ 23,800,000
Valuation allowance		17,962,000	14,670,000
Unrecognized tax benefits		27,256,000	42,695,000	$ 37,531,000	$ 34,117,000
Unrecognized tax benefits that would impact effective tax rate		21,400,000
Interest expense and penalties related to uncertain tax positions		283,000	358,000	$ 263,000
Noncurrent liabilities related to interest and penalties for uncertain tax positions		1,043,000	760,000
Decreased unrecognized tax benefits		(15,400,000)
Long term income taxes payable, including estimated interest and penalties		$ 9,000,000.0
U.S. federal tax authorities [Member] \| Earliest tax year [Member]
Income Taxes [Line Items]
Income tax examination, year		2013
U.S. federal tax authorities [Member] \| Latest tax year [Member]
Income Taxes [Line Items]
Income tax examination, year		2020
U.S. state tax authorities [Member] \| Earliest tax year [Member]
Income Taxes [Line Items]
Income tax examination, year		2009
U.S. state tax authorities [Member] \| Latest tax year [Member]
Income Taxes [Line Items]
Income tax examination, year		2020
Foreign tax authorities [Member] \| Earliest tax year [Member]
Income Taxes [Line Items]
Income tax examination, year		2015
Foreign tax authorities [Member] \| Latest tax year [Member]
Income Taxes [Line Items]
Income tax examination, year		2020
Other Long-Term Liabilities [Member]
Income Taxes [Line Items]
Income tax liabilities considered as other long term liabilities		$ 7,900,000	$ 7,500,000
California state [Member]
Income Taxes [Line Items]
Net operating loss carryforwards		$ 2,700,000
Net operating loss carryforwards begin to expire in fiscal year		2036
Research and development credit carryforwards		$ 27,100,000
Federal [Member]
Income Taxes [Line Items]
Research and development credit carryforwards		$ 22,400,000
Federal credits begin to expire in fiscal year		2035
CARES Act [Member]
Income Taxes [Line Items]
Net operating loss carrybacks on taxable income		100.00%
Increase in allowable business interest deduction of adjusted taxable income		50.00%	30.00%

Income Taxes - Schedule of Reconciliation Between the Provision (Benefit) for Income Taxes at the Statutory Rate and the Effective Tax Rate (Detail) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2021	Jan. 31, 2020	Jan. 31, 2019
Income Tax Disclosure [Abstract]
Provision at U.S. notional statutory rate	$ (12,034)	$ (8,742)	$ (7,256)
U.S. state taxes	212	3	2
Non-U.S. foreign tax differential	12,989	10,458	9,226
Stock-based compensation	4,943	4,172	4,715
U.S. R&D credit	(3,928)	(3,109)	(2,770)
Valuation allowance	0	0	(7,990)
Other	301	382	(32)
Provision (benefit) for income taxes	$ 2,483	$ 3,164	$ (4,105)

- Definition

Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References + Details

Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Jan. 31, 2021	Jan. 31, 2020
Deferred tax assets:
Federal and state credits	$ 24,394	$ 21,275
Expenses not currently deductible	939	593
Operating lease liabilities	2,144	2,023
Stock-based compensation	3,349	3,203
Foreign deferred	184	132
Gross deferred tax assets	31,010	27,226
Valuation allowance	(17,962)	(14,670)
Total deferred tax assets	13,048	12,556
Deferred tax liabilities
Property and equipment	(1,443)	(1,469)
Operating lease assets	(1,978)	(1,974)
Net deferred tax assets	$ 9,627	$ 9,113

Income Taxes - Summary of Tax Valuation Allowance (Detail) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2021	Jan. 31, 2020	Jan. 31, 2019
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	$ 14,670
Balance at End of Period	17,962	$ 14,670
Valuation Allowance of Deferred Tax Assets [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	14,670	12,526	$ 18,538
Additional Charged to Expenses	3,292	2,144	1,978
Additions Charged to Other Account	0	0	0
Deductions Charged to Expenses or Other Accounts	0	0	(7,990)
Balance at End of Period	$ 17,962	$ 14,670	$ 12,526

Income Taxes - Schedule of Reconciliation of Beginning and Ending Amount of Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2021	Jan. 31, 2020	Jan. 31, 2019
Income Tax Disclosure [Abstract]
Beginning balance	$ 42,695	$ 37,531	$ 34,117
Additions based on tax positions related to the current year	3,360	4,964	3,922
Additions for tax positions of prior years	16	252	109
Reductions for tax positions in prior years	(12,483)	0	(552)
Settlements for prior periods	(6,087)	0	0
Lapse of applicable statute of limitations	(245)	(52)	(65)
Ending balance	$ 27,256	$ 42,695	$ 37,531

Commitments and Contingencies - Additional Information (Detail) - USD ($)	12 Months Ended
	Jan. 31, 2021	Jan. 31, 2020
Loss Contingencies [Line Items]
Total manufacturing purchase commitments	$ 48,200,000	$ 35,900,000
Indemnification agreement [Member]
Loss Contingencies [Line Items]
Payments under indemnification obligations	0	0
Liabilities recorded under indemnification obligations	$ 0	$ 0

Segment Reporting - Additional Information (Detail) $ in Thousands	12 Months Ended
	Jan. 31, 2021 USD ($) Segment	Jan. 31, 2020 USD ($)	Jan. 31, 2019
Concentration Risk [Line Items]
Number of reportable segment \| Segment	1
Property and equipment, net	$ 5,530	$ 5,614
Accounts receivable	$ 24,974	$ 18,487
Sales revenue, net [Member] \| Wintech [Member] \| Customer concentration risk [Member]
Concentration Risk [Line Items]
Percentage of revenue	63.00%	60.00%	58.00%
Sales revenue, net [Member] \| Chicony [Member] \| Customer concentration risk [Member]
Concentration Risk [Line Items]
Percentage of revenue	16.00%	18.00%	16.00%
Accounts receivable [Member] \| Wintech [Member] \| Credit concentration risk [Member]
Concentration Risk [Line Items]
Accounts receivable	$ 12,000	$ 3,800
Accounts receivable [Member] \| Chicony [Member] \| Credit concentration risk [Member]
Concentration Risk [Line Items]
Accounts receivable	8,600	10,800
United States [Member]
Concentration Risk [Line Items]
Property and equipment, net	2,000	1,700
Asia Pacific [Member]
Concentration Risk [Line Items]
Property and equipment, net	2,400	2,800
Europe [Member]
Concentration Risk [Line Items]
Property and equipment, net	$ 1,100	$ 1,100

Segment Reporting - Company's Revenue by Geographic Region Based on Bill-to Location (Detail) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2021	Jan. 31, 2020	Jan. 31, 2019
Revenue from External Customer [Line Items]
Total revenue	$ 222,990	$ 228,732	$ 227,768
Taiwan [Member]
Revenue from External Customer [Line Items]
Total revenue	139,327	137,946	132,199
Asia Pacific [Member]
Revenue from External Customer [Line Items]
Total revenue	57,270	66,867	66,981
Europe [Member]
Revenue from External Customer [Line Items]
Total revenue	9,415	11,134	18,244
North America other than United States [Member]
Revenue from External Customer [Line Items]
Total revenue	10,304	8,402	7,028
United States [Member]
Revenue from External Customer [Line Items]
Total revenue	$ 6,674	$ 4,383	$ 3,316

- Definition

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 42
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e9054-108599

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130545-203045

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 924
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 11.L)
-URI http://asc.fasb.org/extlink&oid=6472922&loc=d3e499488-122856

+ Details

Financial Instruments and Fair Value - Schedule of Fair Value of Financial Instruments Measured on Recurring Basis (Detail) - USD ($) $ in Thousands	Jan. 31, 2021	Jan. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents and marketable debt securities	$ 214,802	$ 211,081
Money market funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents and marketable debt securities	171	8,284
Commercial paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents and marketable debt securities	66,181	63,390
Corporate bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents and marketable debt securities	103,081	95,706
Asset-backed securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents and marketable debt securities	15,904	23,129
U.S. government securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents and marketable debt securities	29,465	20,572
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents and marketable debt securities	171	8,284
Level 1 [Member] \| Money market funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents and marketable debt securities	171	8,284
Level 1 [Member] \| Commercial paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents and marketable debt securities	0	0
Level 1 [Member] \| Corporate bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents and marketable debt securities	0	0
Level 1 [Member] \| Asset-backed securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents and marketable debt securities	0	0
Level 1 [Member] \| U.S. government securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents and marketable debt securities	0	0
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents and marketable debt securities	214,631	202,797
Level 2 [Member] \| Money market funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents and marketable debt securities	0	0
Level 2 [Member] \| Commercial paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents and marketable debt securities	66,181	63,390
Level 2 [Member] \| Corporate bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents and marketable debt securities	103,081	95,706
Level 2 [Member] \| Asset-backed securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents and marketable debt securities	15,904	23,129
Level 2 [Member] \| U.S. government securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents and marketable debt securities	29,465	20,572
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents and marketable debt securities	0	0
Level 3 [Member] \| Money market funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents and marketable debt securities	0	0
Level 3 [Member] \| Commercial paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents and marketable debt securities	0	0
Level 3 [Member] \| Corporate bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents and marketable debt securities	0	0
Level 3 [Member] \| Asset-backed securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents and marketable debt securities	0	0
Level 3 [Member] \| U.S. government securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents and marketable debt securities	$ 0	$ 0