Alpha and Omega Semiconductor Limited and its subsidiaries (the “Company”, "AOS", "we" or "us") design, develop and supply a broad range of power semiconductors. The Company's portfolio of products targets high-volume applications, including personal computers, graphic cards, flat panel TVs, home appliances, smart phones, battery packs, quick chargers, home appliances, consumer and industrial motor controls and power supplies for TVs, computers, servers and telecommunications equipment. The Company conducts its operations primarily in the United States of America (“USA”), Hong Kong, China, and South Korea.

The consolidated financial statements include the accounts of the Company, its wholly-owned subsidiaries, and a subsidiary in which it has a controlling interest after elimination of inter-company balances and transactions. The consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America ("U.S. GAAP").

On March 29, 2016, the Company entered into a joint venture contract (the “JV Agreement”) with two investment funds owned by the Municipality of Chongqing (the “Chongqing Funds”), pursuant to which the Company and the Chongqing Funds formed a joint venture, (the “JV Company”), for the purpose of constructing and operating a power semiconductor packaging, testing and 12-inch wafer fabrication facility in the Liangjiang New Area of Chongqing, China (the “JV Transaction”). As of June 30, 2021, the Company owns 51%, and the Chongqing Funds own 49%, of the equity interest in the JV Company. The Joint Venture is accounted under the provisions of the consolidation guidance since the Company has controlling financial interest. If both parties agree that the termination of the JV Company is the best interest of each party or the JV Company is bankrupt or insolvent where either party may terminate early, after paying the debts of the JV Company, the remaining assets of the JV Company shall be paid to the Chongqing Funds to cover the principal of its total paid-in contributions plus interest at 10% simple annual rate prior to distributing the balance of the JV Company's assets to the Company. The JV Company has reached its targeted production of assembly and testing.

The COVID-19 pandemic has had and continues to have a negative impact on business and economic activities across the globe. As a result of the COVID-19 pandemic and the global economic downturn and changing consumer behaviors due to various restrictions imposed by governments, the Company has experienced shifting market trends, including an increasing demand in the markets for notebooks, PCs, gaming devices and other products. While the Company has recently benefited from the increasing demand of PC related products, there is no guarantee that this trend will continue, and such increasing demand may discontinue or decline as government authorities relax COVID-19 related restrictions and consumer behaviors change. Furthermore, as the COVID-19 pandemic continues and global economic downturn and high unemployment persists, consumer spending may slow down substantially, in which case the Company may experience a significant decline of customer orders for its products, including those designed for PC-related applications, and such decline will adversely affect its financial conditions and results of operations. The extent to which the COVID-19 pandemic may impact the Company's business will depend on future developments which are uncertain, such as the duration of the outbreak, travel restrictions, governmental mandates issued to mitigate the spread of the disease, business closures, economic disruptions, and the effectiveness of actions taken to contain and treat the virus. Accordingly, the COVID-19 pandemic may have a negative impact on the Company's sales and results of operations, the size and duration of which is difficult to predict.

The Company is subject to certain risks and uncertainties. The Company believes changes in any of the following areas could have a material adverse effect on the Company's future financial position or results of operations or cash flows: new product development, including market receptiveness, operation of in-house manufacturing facilities, operation of the JV Company, litigation or claims against the Company based on intellectual property, patent, product regulatory or other factors,

competition from other products, general economic conditions, the ability to attract and retain qualified employees, the ability to successfully operate joint venture and ultimately to sustain profitable operations, risks associated with doing business in China, and ability to diversify products and develop digital business; the general state of the U.S., China and world economies; the highly cyclical nature of the industries the Company serves; the loss of any of its larger customers; restrictions on the Company’s ability to sell to foreign customers due to trade laws, regulations and requirements; disruptions of the supply chain of components needed for our products; ability to obtain additional financing; inability to meet certain debt covenants; fundamental changes in the technology underlying the Company’s products; successful and timely completion of product design efforts; and new product design introductions by competitors. Additional risks and uncertainties that the Company is unaware of, or that the Company currently believes are not material, may also become important factors that adversely affect its business.

The semiconductor industry is characterized by rapid technological change, competition, competitive pricing pressures and cyclical market patterns. The Company's financial results are affected by a wide variety of factors, including general economic conditions specific to the semiconductor industry and the Company's particular market, such as the PC markets, the timely implementation of new products, new manufacturing process technology and the ability to safeguard patents and intellectual property in a rapidly evolving market. In addition, the semiconductor market has historically been cyclical and subject to significant economic downturns. As a result, the Company may experience significant period-to-period fluctuations in operating results due to the factors mentioned above or other factors.

The Company's revenue may be impacted by its ability to utilize wafer production and packaging and testing capacity from its in-house facilities and obtain adequate wafer supplies from third-party foundries. Currently the Company's main third-party foundry is Shanghai Hua Hong Grace Electronic Company Limited, or HHGrace, located in Shanghai, China. HHGrace has been manufacturing wafers for the Company since 2002. HHGrace manufactured approximately 11.5%, 12.7% and 14.1% of the wafers used in the Company's products for the fiscal years ended June 30, 2021, 2020 and 2019, respectively. Although the Company believes that its volume of production allows the Company to secure favorable pricing and priority in allocation of capacity in its third-party foundries, if the foundries' capacities are constrained due to market demands, HHGrace, together with other foundries from which the Company purchases wafers, may not be willing or able to satisfy all of the Company's manufacturing requirements on a timely basis and/or at favorable prices. The Company is also subject to the risks of service disruptions and raw material shortages by its foundries. Such disruptions, shortages and price increases could harm the Company's operating results. In addition, manufacturing facilities' capacity affects the Company's gross margin because the Company has certain fixed costs associated with its Oregon fab and the JV Company, as well as in-house packaging and testing facilities. If the Company fails to utilize its manufacturing facilities' capacity at a desirable level, its financial condition and results of operations will be adversely affected.

The preparation of the consolidated financial statements in conformity with U.S. GAAP requires the Company to make estimates, judgments and assumptions that affect the reported amounts of assets, liabilities, revenue and expenses. To the extent there are material differences between these estimates and actual results, the Company's condensed consolidated financial statements will be affected. On an ongoing basis, the Company evaluates the estimates, judgments and assumptions including those related to stock rotation returns, price adjustments, allowance for doubtful accounts, inventory reserves, warranty accrual, income taxes, leases, share-based compensation, recoverability of and useful lives for property, plant and equipment and intangible assets, as well as the economic implications of the COVID-19 pandemic.

Most of the Company's principal subsidiaries use U.S. dollars as their functional currency because their transactions are primarily conducted and settled in U.S. dollars. All of their revenues and a significant portion of their operating expenses are denominated in U.S. dollars. The functional currencies for the Company's in-house packaging and testing facilities in China are U.S. dollars, and a majority of their capital expenditures are denominated in U.S. dollars. Foreign currency transactions are translated into the functional currencies using the exchange rates prevailing at the dates of the transactions. Foreign exchange gains and losses, resulting from the settlement of such transactions and from the re-measurement of monetary assets and liabilities denominated in foreign currencies using exchange rates at balance sheet date and non-monetary assets and liabilities using historical exchange rates, are recognized in the consolidated statements of operations.

Cash and cash equivalents primarily consist of cash on hand and short-term bank deposits with original maturities of three months or less. Cash equivalents are highly liquid investments with stated maturities of three months or less as of the dates of purchase. The carrying amounts reported for cash and cash equivalents are considered to approximate fair values based upon their short maturities.

Cash and cash equivalents are maintained with reputable major financial institutions. If, due to current economic conditions or other factors, one or more of the financial institutions with which the Company maintains deposits fails, the Company's cash and cash equivalents may be at risk. Deposits with these banks may exceed the amount of insurance provided on such deposits; however, these deposits typically may be redeemed upon demand and, therefore, bear minimal risk.

As a condition of the loan arrangements, the Company is required to keep a compensating balance at the issuing bank (see Note 5). In addition, the Company maintains restricted cash in connection with cash balances temporarily restricted for regular business operations, including the possibility of a dispute with a vendor. These balances have been excluded from the Company’s cash and cash equivalents balance and are classified as restricted cash in the Company’s consolidated balance sheets. As of June 30, 2021 and 2020, the amount of restricted cash was $2.4 million and $4.2 million, respectively.

The allowance for doubtful accounts is based on assessment of the collectability of accounts receivable from customers. The Company reviews the allowance by considering factors such as historical collection experience, credit quality, age of the accounts receivable balances and current economic conditions that may affect a customer's ability to pay. The Company writes off a receivable and charges against its recorded allowance when it has exhausted its collection efforts without success.

Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. The fair value hierarchy is based on three levels of inputs, of which the first two are considered observable and the last unobservable, that may be used to measure fair value, which are the following:

The fair value of cash equivalents is based on observable market prices and have been categorized in Level 1 in the fair value hierarchy. Cash equivalents consist primarily of short-term bank deposits. The carrying values of financial instruments such as cash and cash equivalents, accounts receivable and accounts payable approximate their carrying values due to their short-term maturities. The carrying value of the company's debt is considered a reasonable estimate of fair value which is estimated by considering the current rates available to the Company for debt of the same remaining maturities, structure and terms of the debts.

The Company carries inventories at the lower of cost (determined on a first-in, first-out basis) or net realizable value. Cost includes semiconductor wafer and raw materials, labor, depreciation expenses and other manufacturing expenses and overhead, and packaging and testing fees paid to third parties if subcontractors are used. Valuation of inventories are based on the Company's periodic review of inventory quantities on hand as compared with its sales forecasts, historical usage, aging of

inventories, production yield levels and current product selling prices. If actual market conditions are less favorable than those forecasted by management, additional future inventory write-downs may be required that could adversely affect the Company's operating results. Adjustments to inventory once established are not reversed until the related inventory has been sold or scrapped.

Internal-use software development costs are capitalized to the extent that the costs are directly associated with the development of identifiable and unique software products controlled by the Company that will probably generate economic benefits beyond one year. Costs incurred during the application development stage are required to be capitalized. The application development stage is characterized by software design and configuration activities, coding, testing and installation. Training costs and maintenance are expensed as incurred, while upgrades and enhancements are capitalized if it is probable that such expenditures will result in additional functionality. Costs include employee costs incurred and fees paid to outside consultants for the software development and implementation. Internally developed software is amortized over its estimated useful life of three to five years starting from the date when it is ready for its intended use.

The Company occasionally receives government grants that provide financial assistance for certain eligible expenditures in China. These grants include reimbursements on interest expense on bank borrowings, payroll tax credits, credit for property, plant and equipment in a particular geographical location, employment credits, , as well as business expansion credits. Government grants are not recognized until there is reasonable assurance that the Company will comply with the conditions attaching to it, and that the grant will be received. The Company records such grants either as a reduction of the related expense, a reduction of the cost of the related asset, or as other income depending upon the nature of the grant. As a result of such grants, during the fiscal year ended June 30, 2021, the Company reduced interest expense by $3.0 million, property, plant and equipment by $0.1 million, and operating expenses by $3.7 million. During the fiscal year ended June 30, 2020, the Company reduced interest expense by $6.1 million, property, plant and equipment by $1.3 million, and operating expenses by $4.7 million. During the fiscal year ended June 30, 2019, the Company reduced interest expenses by $0.3 million.

The Company evaluates its long-lived assets for impairment whenever events or changes indicate that the carrying amount of such assets may not be recoverable. Due to the COVID-19 pandemic, the Company assessed the changes in circumstances that occurred during the March and June 2020 quarters. These factors included continued operating losses, a decrease in the Company's share price in February and March of 2020, which reduced its market capitalization, expectation of lower business growth for the coming quarters, increased and prolonged economic and regulatory uncertainty in the global economies, and the expectation of higher supply chain costs and increased competition. Therefore, the Company performed a recoverability test by comparing the sum of the estimated undiscounted future cash flows of its long-lived assets to their carrying amount as of June 30, 2020. Some of the more significant assumptions used in the estimated future cash flows involve net sales, cost of goods sold, operating expenses, working capital, capital expenditures, income tax rates, long-term growth rates that appropriately reflect the risks inherent in the future cash flow stream and terminal value. The Company selected the assumptions used in the financial forecasts by referencing to historical data, supplemented by current and anticipated market conditions, estimated product growth rates and management's plans. These estimated future cash flows were consistent with those the Company uses in its internal planning. The result of the recoverability test indicated that the sum of the expected future cash flows (undiscounted and without interest charges) was greater than the carrying amount of the long-lived assets. Therefore, the Company concluded that the carrying amount of the long-lived assets is recoverable. There was no impairment of long-lived assets for fiscal years 2021, 2020 and 2019.

The Company determines revenue recognition through the following steps: (1) identification of the contract with a customer; (2) identification of the performance obligations in the contract; (3) determination of the transaction price; (4) allocation of the transaction price to the performance obligations in the contract; and (5) recognition of revenue when, or as, a performance obligation is satisfied. The Company recognizes product revenue at a point in time when product is shipped to the customer, net of estimated stock rotation returns and price adjustments that it expects to provide to certain distributors. The Company presents revenue net of sales taxes and any similar assessments. Our standard payment terms range from 30 to 90 days.

The Company sells its products primarily to distributors, who in turn sell the products globally to various end customers. The Company allows stock rotation returns from certain distributors. Stock rotation returns are governed by contract and are limited to a specified percentage of the monetary value of products purchased by distributors during a specified period. The Company records an allowance for stock rotation returns based on historical returns and individual distributor agreements. The Company also provides special pricing to certain distributors, primarily based on volume, to encourage resale of the Company's products. Allowance for price adjustments is recorded against accounts receivable and the provision for stock rotation rights is included in accrued liabilities on the consolidated balance sheets.

The Company's performance obligations relate to contracts with a duration of less than one year. The Company elected to apply the practical expedient provided in ASC 606, “Revenue from Contracts with Customers”. Therefore, the Company is not required to disclose the aggregate amount of transaction price allocated to performance obligations that are unsatisfied or partially unsatisfied at the end of the reporting period.

The Company recognizes the incremental direct costs of obtaining a contract, which consist of sales commissions, when control over the products they relate to transfers to the customer. Applying the practical expedient, the Company recognizes commissions as expense when incurred, as the amortization period of the commission asset the Company would have otherwise recognized is less than one year.

The Company determines if an arrangement is a lease at inception. Operating leases are included in operating lease right-of-use ("ROU") assets, current operating lease liabilities and long-term operating lease liabilities on the Company's consolidated balance sheets. Finance leases are included in property, plant and equipment, finance lease liabilities and long-term finance leases liabilities on the consolidated balance sheets.

Operating lease ROU assets and operating lease liabilities are recognized based on the present value of the future minimum lease payments over the lease term at commencement date. The Company uses an estimate of its incremental borrowing rate based on the information available at the lease commencement date. The operating lease ROU assets also include any lease payments made and exclude lease incentives. Lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise such options. Operating lease expense is generally

recognized on a straight-line basis over the lease term. Variable lease payments are expensed as incurred and are not included within the operating lease ROU asset and lease liability calculation. The Company does not record leases on the consolidated balance sheet with a term of one year or less. The Company elected to combine its lease and non-lease components as a single lease component for all asset classes.

The Company provides a standard one-year warranty for the products from the date of purchase by the end customers. The Company accrues for estimated warranty costs at the time revenue is recognized. The Company's warranty obligation is affected by product failure rates, labor and material costs for replacing defective parts, related freight costs for failed parts and other quality assurance costs. The Company monitors its product returns for warranty claims and maintains warranty reserves based on historical experiences and anticipated warranty claims known at the time of estimation.

The Company is subject to income taxes in a number of jurisdictions. Significant judgment is required in determining the worldwide provision for income taxes. There are many transactions and calculations for which the ultimate tax determination is uncertain during the ordinary course of business. The Company establishes accruals for certain tax contingencies based on estimates of whether additional taxes may be due. While the final tax outcome of these matters may differ from the amounts that were initially recorded, such differences will impact the income tax and deferred tax provisions in the period in which such determination is made.

Significant management judgment is also required in determining whether deferred tax assets will be realized in full or in part. When it is more likely than not that all or some portion of specific deferred tax assets such as net operating losses or research and experimentation tax credit carryforwards will not be realized, a valuation allowance must be established for the amount of the deferred tax assets that cannot be realized. The Company considers all available positive and negative evidence on a jurisdiction-by-jurisdiction basis when assessing whether it is more likely than not that deferred tax assets are recoverable. The Company considers evidence such as our past operating results, the existence of cumulative losses in recent years and our forecast of future taxable income.

The Financial Accounting Standards Board, or FASB, issued guidance which clarifies the accounting for income taxes by prescribing a minimum probability threshold that a tax position must meet before a financial statement benefit is recognized. The minimum threshold is defined as a tax position that is more likely than not to be sustained upon examination by the applicable taxing authority, including resolution of any related appeals or litigation processes, based on the technical merits of the position. The tax benefit to be recognized is measured as the largest amount of benefit that is greater than fifty percent likely to be realized upon ultimate settlement. Although the guidance on the accounting for uncertainty in income taxes prescribes the use of a recognition and measurement model, the determination of whether an uncertain tax position has met those thresholds will continue to require significant judgment by management. If the ultimate resolution of tax uncertainties is different from what is currently estimated, a material impact on income tax expense could result.

The Company's provision for income taxes is subject to volatility and could be adversely impacted by changes in earnings or tax laws and regulations in various jurisdictions. The Company is subject to the continuous examination of our income tax returns by the Internal Revenue Service and other tax authorities. The Company regularly assesses the likelihood of adverse outcomes resulting from these examinations to determine the adequacy of our provision for income taxes. To the extent that the final tax outcome of these matters is different from the amounts recorded, such differences will impact the provision for income taxes in the period in which such determination is made. The provision for income taxes includes the impact of changes to reserves, as well as the related net interest and penalties.

The Company maintains an equity-settled, share-based compensation plan to grant restricted share units and stock options. The Company recognizes expense related to share-based compensation awards that are ultimately expected to vest based on estimated fair values on the date of grant. The fair value of restricted share units is based on the fair value of the Company's common share on the date of grant. For restricted stock awards subject to market conditions, the fair value of each restricted stock award is estimated at the date of grant using the Monte-Carlo pricing model. The fair value of stock options is estimated on the date of grant using the Black-Scholes option valuation model. Share-based compensation expense is recognized on the accelerated attribution basis over the requisite service period of the award, which generally equals the vesting period.

In August 2020, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2020-06, Debt—Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging—Contracts in Entity’s Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity, which, among other things, provides guidance on how to account for contracts on an entity’s own equity. This ASU simplifies the accounting for certain financial instruments with characteristics of liabilities and equity. Specifically, the ASU eliminated the need for the Company to assess whether a contract on the entity’s own equity (1) permits settlement in unregistered shares, (2) whether counterparty rights rank higher than shareholder’s rights, and (3) whether collateral is required. In addition, the ASU requires incremental disclosure related to contracts on the entity’s own equity and clarifies the treatment of certain financial instruments accounted for under this ASU on earnings per share. For public business entities, the ASU is effective for fiscal years beginning after December 15, 2021, and interim periods within those fiscal years. The Company does not expect the adoption of this guidance will have a material impact on its consolidated financial position, results of operations or cash flows.

In January 2020, the FASB issued ASU No. 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 ASU is based on a consensus of the Emerging Issues Task Force and is expected to increase comparability in accounting for these transactions. ASU 2016-01 made targeted improvements to accounting for financial instruments, including providing an entity the ability to measure certain equity securities without a readily determinable fair value at cost, less any impairment, plus or minus changes resulting from observable price changes in orderly transactions for the identical or a similar investment of the same issuer. Among other topics, the amendments clarify that an entity should consider observable transactions that require it to either apply or discontinue the equity method of accounting. For public business entities, the amendments in the ASU are effective for fiscal years beginning after December 15, 2020, and interim periods within those fiscal years. The Company does not expect the adoption of this guidance will have a material impact on its consolidated financial position, results of operations or cash flows.

In December 2019, the FASB issued ASU No. 2019-12 “Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes ("ASU 2019-12") by removing certain exceptions to the general principles. The amendments will be effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2020. Early adoption of the amendments is permitted. Depending on the amendment, adoption may be applied on a retrospective, modified retrospective or prospective basis. The Company is currently evaluating the impacts of adoption of the new guidance to its consolidated financial statements.

In August 2018, the FASB issued ASU 2018-15 “Intangibles - Goodwill and Other - Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract" ("ASU 2018-15"). These amendments align the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contact with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software (and hosting arrangements that include an internal-use software license). The accounting for the service element of a hosting arrangement that is a service contract is not affected by these amendments. ASU 2018-15 had no material impact on the Company's consolidated financial statements.

In August 2018, the FASB issued ASU 2018-13, “Fair Value Measurement (Topic 820): Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement ("ASU 2018-13”). ASU 2018-13 amends existing fair value measurement disclosure requirements by adding, changing, or removing certain disclosures. The amendments on changes in unrealized gains and losses, the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements, and the narrative description of measurement uncertainty should be applied prospectively for only the most recent interim or annual period presented in the initial fiscal year of adoption. All other amendments should be applied retrospectively to all periods presented upon their effective date. ASU 2018-13 had no material impact on the Company's consolidated financial statements.

In June 2016, the FASB issued ASU 2016-13, "Financial Instruments - Credit Losses (Topic 326). Topic 326 adds to U.S. GAAP the current expected credit loss ("CECL") model, a measurement model based on expected losses rather than incurred losses. Under this new standard, an entity recognizes its estimate of expected credit losses as an allowance. The new standard is also intended to reduce the complexity of U.S. GAAP by decreasing the number of credit loss models that entities use to account for debt instruments. The new guidance significantly changes the accounting for credit losses. The Company adopted

The adoption of Topic 326 did not significantly change the Company's approach to the valuation of trade receivables. The Company determines whether there is an expected loss on its accounts receivable by reviewing all available data, including its customers' latest available financial statements, their credit standing and historical collection experience, as well as current and future market and economic conditions. As of June 30, 2021, the allowance for credit losses on the Company's trade receivables remained immaterial.