Document and Entity Information - shares	6 Months Ended
Document and Entity Information - shares	Dec. 31, 2015	Jan. 31, 2016
Document and Entity Information [Abstract]
Entity Registrant Name	ALPHA & OMEGA SEMICONDUCTOR Ltd
Entity Central Index Key	0001387467
Current Fiscal Year End Date	--06-30
Entity Filer Category	Accelerated Filer
Document Type	10-Q
Document Period End Date	Dec. 31, 2015
Document Fiscal Year Focus	2016
Document Fiscal Period Focus	Q2
Amendment Flag	false
Entity Common Stock, Shares Outstanding		22,137,610

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2015	Jun. 30, 2015
Current assets:
Cash and cash equivalents	$ 81,858	$ 106,085
Restricted cash	231	368
Accounts receivable, net	26,054	38,781
Inventories	61,102	64,175
Deferred income tax assets	2,403	2,205
Other current assets	3,220	4,279
Total current assets	174,868	215,893
Property, plant and equipment, net	112,057	119,579
Intangible assets, net	16	17
Goodwill	269	269
Deferred income tax assets - long term	10,316	10,848
Other long-term assets	2,240	2,011
Total assets	299,766	348,617
Current liabilities:
Accounts payable	33,875	44,083
Accrued liabilities	20,103	19,225
Income taxes payable	1,710	1,372
Deferred margin	761	716
Capital leases	485	941
Total current liabilities	56,934	66,337
Income taxes payable - long term	1,626	1,601
Deferred income tax liabilities	3,720	3,548
Capital leases - long term	64	64
Other long term liabilities	851	953
Total liabilities	$ 63,195	$ 72,503
Commitments and contingencies (Note 8)
Preferred shares, par value $0.002 per share:
Authorized: 10,000 shares, issued and outstanding: none at December 31, 2015 and June 30, 2015	$ 0	$ 0
Common shares, par value $0.002 per share:
Authorized: 50,000 shares, issued and outstanding: 27,783 shares and 22,297 shares, respectively at December 31, 2015 and 27,314 shares and 26,316 shares, respectively at June 30, 2015	56	55
Treasury shares at cost, 5,486 shares at December 31, 2015 and 998 shares at June 30, 2015	(48,808)	(8,593)
Additional paid-in capital	185,495	181,040
Accumulated other comprehensive income	750	905
Retained earnings	99,078	102,707
Total shareholders’ equity	236,571	276,114
Total liabilities and shareholders’ equity	$ 299,766	$ 348,617

CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Dec. 31, 2015	Jun. 30, 2015
Common shares, par value (in dollars per share)	$ 0.002	$ 0.002
Common shares, authorized (in shares)	50,000,000	50,000,000
Common stock, shares issued (in shares)	27,783,000	27,314,000
Common stock, shares outstanding (in shares)	22,297,000	26,316,000
Preferred stock, par value (in dollars per share)	$ 0.002	$ 0.002
Preferred stock, shares authorized (in shares)	10,000,000	10,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Treasury shares (in shares)	5,486,000	998,000

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2015	Dec. 31, 2014
Revenue	$ 79,825	$ 81,328	$ 161,264	$ 169,545
Cost of goods sold	64,853	66,086	131,231	136,143
Gross profit	14,972	15,242	30,033	33,402
Operating expenses
Research and development	5,941	6,430	12,105	13,226
Selling, general and administrative	9,197	9,135	18,856	18,739
Impairment of long-lived assets	432	0	432	0
Total operating expenses	15,570	15,565	31,393	31,965
Operating income (loss)	(598)	(323)	(1,360)	1,437
Interest income and other, net	9	26	20	74
Interest expense	(7)	(43)	(17)	(116)
Income (loss) before income taxes	(596)	(340)	(1,357)	1,395
Income tax expense	1,015	957	2,229	2,128
Net loss	$ (1,611)	$ (1,297)	$ (3,586)	$ (733)
Net loss per share
Basic (in dollars per share)	$ (0.07)	$ (0.05)	$ (0.16)	$ (0.03)
Diluted (in dollars per share)	$ (0.07)	$ (0.05)	$ (0.16)	$ (0.03)
Weighted average number of common shares used to compute net loss per share
Basic (in shares)	22,269	26,577	22,483	26,481
Diluted (in shares)	22,269	26,577	22,483	26,481

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2015	Dec. 31, 2014
Net loss	$ (1,611)	$ (1,297)	$ (3,586)	$ (733)
Foreign currency translation adjustment, net of tax	11	(98)	(155)	(146)
Total comprehensive loss	$ (1,600)	$ (1,395)	$ (3,741)	$ (879)

- Definition

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

+ References + Details

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Cash flows from operating activities
Net loss	$ (3,586)	$ (733)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation	13,777	13,911
Amortization	1	139
Share-based compensation expense	1,874	2,379
Deferred income taxes, net	506	(174)
Loss on disposal of property and equipment	0	36
Impairment of long-lived assets	432	0
Government grant via forgiven loan	0	(250)
Changes in assets and liabilities:
Accounts receivable	12,727	9,830
Inventories	3,073	(3,422)
Other current and long-term assets	831	307
Accounts payable	(6,454)	(6,940)
Income taxes payable	364	(502)
Accrued and other liabilities	897	471
Net cash provided by operating activities	24,442	15,052
Cash flows from investing activities
Purchases of property and equipment	(10,770)	(6,938)
Restricted cash released	137	40
Net cash used in investing activities	(10,633)	(6,898)
Cash flows from financing activities
Proceeds from exercise of stock options and ESPP	2,772	1,759
Payment for repurchase of common shares	(40,257)	0
Repayments of borrowings	0	(6,429)
Principal payments on capital leases	(456)	(551)
Net cash used in financing activities	(37,941)	(5,221)
Effect of exchange rate changes on cash and cash equivalents	(95)	(74)
Net increase (decrease) in cash and cash equivalents	(24,227)	2,859
Cash and cash equivalents at beginning of period	106,085	117,788
Cash and cash equivalents at end of period	81,858	120,647
Supplemental disclosures of non-cash investing and financing information:
Property and equipment purchased but not yet paid	1,645	5,673
Re-issuance of treasury stock	$ 43	$ 35

The Company and Significant Accounting Policies	6 Months Ended
The Company and Significant Accounting Policies	Dec. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
The Company and Significant Accounting Policies	The Company and Significant Accounting Policies The Company 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, flat panel TVs, LED lighting, smart phones, battery packs, 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, Taiwan, Korea and Japan. Basis of Preparation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“U.S. GAAP”) for interim financial information and with the instructions to Article 10 of Securities and Exchange Commission Regulation S-X, as amended. They do not include all information and footnotes necessary for a fair presentation of financial position, results of operations and cash flows in conformity with U.S. GAAP for complete financial statements. These condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and related notes contained in the Company’s Annual Report on Form 10-K for the fiscal year ended June 30, 2015. All significant intercompany balances and transactions have been eliminated in consolidation. In the opinion of management, all adjustments (consisting of normal recurring adjustments and accruals) considered necessary for a fair presentation of the results of operations for the period presented have been included in the interim periods. Operating results for the six months ended December 31, 2015 are not necessarily indicative of the results that may be expected for the fiscal year ending June 30, 2016. The condensed consolidated balance sheet at June 30, 2015 is derived from the audited financial statements included in the Company’s Annual Report on Form 10-K for the fiscal year ended June 30, 2015. Use of Estimates The preparation of the condensed 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, share-based compensation, and useful lives for property, plant and equipment and intangible assets. Fair Value of Financial Instruments The fair value of cash equivalents are 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. Impairment of Long-Lived Assets Long-lived assets or asset groups are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset might not be recoverable. Factors that would necessitate an impairment assessment include a significant decline in the observable market value of an asset, a significant change in the extent or manner in which an asset is used, or any other significant adverse change that would indicate that the carrying amount of an asset or group of assets may not be recoverable. Where such factors indicate potential impairment, the recoverability of an asset or asset group is assessed by determining if the carrying value of the asset or asset group exceeds the sum of the projected undiscounted cash flows expected to result from the use and eventual disposition of the assets over the remaining economic life. The impairment loss is measured based on the difference between the carrying amount and estimated fair value. Comprehensive Income (Loss) Comprehensive income (loss) is defined as the change in equity of a business enterprise during a period from transactions and other events and circumstances from non-owner sources. The Company's accumulated other comprehensive income (loss) consists of cumulative foreign currency translation adjustments. Total comprehensive income (loss) is presented in the condensed consolidated statements of comprehensive income (loss). Recent Accounting Pronouncements In July 2015, the FASB issued No. 2015-11, Inventory - Simplifying the Measurement of Inventory ("ASU 2015-11"). ASU 2015-11 is additional guidance regarding the subsequent measurement of inventory by requiring inventory to be measured at the lower of cost and net realizable value. This guidance is effective for fiscal years and interim periods beginning after December 15, 2016. Early adoption is permitted. 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 April 2015, the FASB issued ASU No. 2015-03, Interest -Imputation of Interest(Subtopic 835-30): Simplifying the Presentation of Debt Issuance Costs. The amendments in this ASU require that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts and the accounting for debt issue costs under IFRS. The recognition and measurement guidance for debt issuance costs are not affected by the amendments in this ASU. ASU 2015-03 is effective for the annual period ending after December 15, 2015, and interim periods within those fiscal years. Early adoption of the amendments in this Update is permitted for financial statements that have not been previously issued. 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 February 2015, the FASB issued ASU No. 2015-2, “Consolidation (Topic 820): Amendments to the Consolidation Analysis.” ASU 2015-2 provides a revised consolidation model for all reporting entities to use in evaluating whether they should consolidate certain legal entities. All legal entities will be subject to reevaluation under this revised consolidation model. The revised consolidation model, among other things, (i) modifies the evaluation of whether limited partnerships and similar legal entities are VIEs or voting interest entities, (ii) eliminates the presumption that a general partner should consolidate a limited partnership, and (iii) modifies the consolidation analysis of reporting entities that are involved with VIEs through fee arrangements and related party relationships. ASU 2015-2 is effective for fiscal years, and interim reporting periods within those fiscal years, beginning after December 15, 2015. 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 August 2014, the FASB issued amended standards No. 2014-15, Presentation of Financial Statements - Going Concern ("ASU 2014-15"), to provide guidance about management’s responsibility to evaluate whether there is substantial doubt about an entity’s ability to continue as a going concern and to provide related footnote disclosures requirement. The amendments (1) provide a definition of the term substantial doubt, (2) require an evaluation for each annual and interim reporting period, (3) provide principles for considering the mitigating effect of management’s plans, (4) require certain disclosures when substantial doubt is alleviated as a result of consideration of management’s plans, (5) require an express statement and other disclosures when substantial doubt is not alleviated, and (6) require an assessment for a period of one year after the date that the financial statements are issued (or available to be issued). ASU 2014-15 is effective for the annual period ending after December 15, 2016, and for annual periods and interim periods thereafter. Early adoption is permitted. 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 May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers(“ASU 2014-09”). The standard provides companies with a single model for use in accounting for revenue arising from contracts with customers and supersedes current revenue recognition guidance, including industry-specific revenue guidance. The core principle of the model is to recognize revenue when control of the goods or services transfers to the customer, as opposed to recognizing revenue when the risks and rewards transfer to the customer under the existing revenue guidance. ASU 2014-09 is effective for annual reporting periods beginning after December 15, 2016. The guidance permits companies to either apply the requirements retrospectively to all prior periods presented, or apply the requirements in the year of adoption, through a cumulative adjustment. In July 2015, the FASB voted to amend ASU 2014-09 by approving a one-year deferral of the effective date as well as providing the option to early adopt the standard on the original effective date. In August 2015 the FASB issued ASU 2015-14, Revenue from Contracts with customers - Deferral of the Effective Date", that defers by one year the effective date of ASU 2014-09. The ASU is effective for annual reporting periods beginning after December 15, 2017, including interim periods within that reporting period. The Company is in the process of evaluating the timing of its adoption and the impact of adoption on its consolidated financial statements.

Net Income (Loss) Per Share

6 Months Ended

Dec. 31, 2015

Earnings Per Share [Abstract]

Net Income (Loss) Per Share

Net Loss Per Share

The following table presents the calculation of basic and diluted net loss per share:



	Three Months Ended December 31,						Six Months Ended December 31,
	2015			2014			2015			2014
	(in thousands, except per share data)
Numerator:
Net loss	$	(1,611	)	$	(1,297	)	$	(3,586	)	$	(733	)

Denominator:
Basic:
Weighted average number of common shares used to compute basic net loss per share	22,269			26,577			22,483			26,481
Diluted:
Weighted average number of common shares used to compute diluted net loss per share	22,269			26,577			22,483			26,481
Net loss per share:
Basic	$	(0.07	)	$	(0.05	)	$	(0.16	)	$	(0.03	)
Diluted	$	(0.07	)	$	(0.05	)	$	(0.16	)	$	(0.03	)

The following potential dilutive securities were excluded from the computation of diluted net loss per share as their effect would have been anti-dilutive:



	Three Months Ended December 31,		Six Months Ended December 31,
	2015	2014	2015	2014
	(in thousands)
Employee stock options and RSUs	3,299	3,694	3,458	3,758
ESPP to purchase common shares	551	462	369	441
Total potential dilutive securities	3,850	4,156	3,827	4,199

Concentration of Credit Risk and Significant Customers

6 Months Ended

Dec. 31, 2015

Risks and Uncertainties [Abstract]

Concentration of Credit Risk and Significant Customers

The Company manages its credit risk associated with exposure to distributors and direct customers on outstanding accounts receivable through the application of credit approvals, credit ratings and other monitoring procedures. In some instances, the Company also obtains letters of credit from certain customers.

Credit sales, which are mainly on credit terms of 30 to 60 days, are only made to customers who meet the Company's credit requirements, while sales to new customers or customers with low credit ratings are usually made on an advance payment basis. The Company considers its trade accounts receivable to be of good credit quality because its key distributors and direct customers have long-standing business relationships with the Company and the Company has not experienced any significant bad debt write-offs of accounts receivable in the past. The Company closely monitors the aging of accounts receivable from its distributors and direct customers, and regularly reviews their financial positions, when available.

Summarized below are individual customers whose revenue or accounts receivable balances were 10% or higher than the respective total consolidated amounts:



	Three Months Ended December 31,				Six Months Ended December 31,
Percentage of revenue	2015		2014		2015		2014
Customer A	24.0	%	24.2	%	23.6	%	24.2	%
Customer B	39.6	%	37.1	%	37.8	%	38.4	%
Customer C	10.8	%	11.5	%	12.6	%	12.2	%



	December 31, 2015		June 30, 2015
Percentage of accounts receivable	December 31, 2015		June 30, 2015
Customer A	28.5	%	29.4	%
Customer B	18.4	%	27.7	%
Customer C	21.8	%	14.7	%

Balance Sheet Components

6 Months Ended

Dec. 31, 2015

Balance Sheet Related Disclosures [Abstract]

Balance Sheet Components

Accounts receivable:



	December 31, 2015			June 30, 2015
	(in thousands)
Accounts receivable	$	42,489		$	58,249
Less: Allowance for price adjustments	(16,405		)	(19,438		)
Less: Allowance for doubtful accounts	(30		)	(30		)
Accounts receivable, net	$	26,054		$	38,781

Inventories:



	December 31, 2015		June 30, 2015
	(in thousands)
Raw materials	$	18,917	$	19,423
Work in-process	33,015		31,269
Finished goods	9,170		13,483
	$	61,102	$	64,175

Property, plant and equipment, net:



	December 31, 2015			June 30, 2015
	(in thousands)
Land	$	4,877		$	4,877
Building	4,243			4,243
Manufacturing machinery and equipment	187,862			172,467
Equipment and tooling	12,125			11,261
Computer equipment and software	20,931			20,602
Office furniture and equipment	1,780			1,762
Leasehold improvements	28,098			27,568
	259,916			242,780
Less: Accumulated depreciation	(155,416		)	(141,883		)
	104,500			100,897
Equipment and construction in progress	7,557			18,682
Property, plant and equipment, net	$	112,057		$	119,579

Other long-term assets:



	December 31, 2015		June 30, 2015
	(in thousands)
Prepayments for property and equipment	$	324	$	692
Investment in a privately held company	100		100
Office leases deposits	1,814		1,215
Other	2		4
	$	2,240	$	2,011

Accrued liabilities:



	December 31, 2015		June 30, 2015
	(in thousands)
Accrued compensation and benefit	$	6,387	$	5,600
Accrued vacation	1,771		1,830
Accrued bonuses	1,292		1,152
Warranty accrual	1,596		1,957
Stock rotation accrual	1,872		1,894
Accrued professional fees	1,631		1,402
ESPP payable	357		343
Customer deposits	830		149
Accrued inventory	268		697
Accrued facilities related expenses	1,469		1,367
Other accrued expenses	2,630		2,834
	$	20,103	$	19,225

The activities in the warranty accrual, included in accrued liabilities, are as follows:



	Six Months Ended December 31,
	2015			2014
	(in thousands)
Beginning balance	$	1,957		$	1,346
Additions	747			910
Utilization	(1,108		)	(1,068		)
Ending balance	$	1,596		$	1,188

The activities in the stock rotation accrual, included in accrued liabilities, are as follows:



	Six Months Ended December 31,
	2015			2014
	(in thousands)
Beginning balance	$	1,894		$	1,645
Additions	3,120			2,820
Utilization	(3,142		)	(2,802		)
Ending balance	$	1,872		$	1,663

Other Long-term liabilities:



	December 31, 2015		June 30, 2015
	(in thousands)
Deferred rent	$	851	$	953

Shareholders' Equity and Share-based Compensation

6 Months Ended

Dec. 31, 2015

Share-based Compensation [Abstract]

Shareholders' Equity and Share-based Compensation

Share Repurchase

In April 2015, the Board of Directors approved an increase in the remaining available amount under the Company’s then effective share repurchase program from approximately $17.8 million to $50.0 million. The repurchases may be made from the open market pursuant to a pre-established Rule 10b5-1 trading plan (as amended, the "Repurchase Trading Plan") or through privately negotiated transactions. The amount and timing of any repurchases depend on a number of factors, including but not limited to, the Company's trading price, volume and availability of its common shares, applicable legal requirements, its business and financial conditions an general market environment. There is no guarantee that any repurchases under the Program will be made or that such repurchases would enhance the value of our shares. The Company accounts for treasury stock under the cost method. Shares repurchased are accounted for as treasury shares and the total cost of shares repurchased is recorded as a reduction of shareholders' equity. From time to time, treasury shares may be reissued as part of the Company's stock-based compensation programs. Gains on re-issuance of treasury stock are credited to additional paid-in capital; losses are charged to additional paid-in capital to offset the net gains, if any, from previous sales or re-issuance of treasury stock. Any remaining balance of the losses are charged to retained earnings.

In June 2015, the Company commenced a modified Dutch auction tender offer (the "Tender Offer") to repurchase an aggregate of $30.0 million of its outstanding common shares with a price range between $8.50 and $9.20 per share. In July 2015, the Company completed the Tender Offer in which it purchased 3,296,703 shares of its common shares, at a purchase price of $9.10 per share, for an aggregate purchase price of $30.0 million, excluding fees and expenses relating to the Tender Offer. These shares represented approximately 12.53% of the total number of the Company's common shares issued and outstanding as of June 30, 2015. The Tender Offer was part of the $50.0 million share repurchase program approved by the Board in April 15, 2015. Immediately following the completion of the Tender Offer, approximately $18.2 million remained available under the share repurchase program.

During the six months ended December 31, 2015, the Company repurchased 4,491,375 shares from the open market, including 3,296,703 shares in the Tender Offer, for a total cost of $40.0 million, at an average price of $8.90 per share, excluding fees and related expenses of $0.3 million, under the share repurchase program. Since the inception of the program in 2010, the Company repurchased an aggregate of 5,518,969 shares from the open market for a total cost of $48.9 million, at an average price of $8.87 per share, excluding fees and related expenses. No repurchased shares have been retired. Of the 5,518,969 repurchased shares, 32,766 shares with a weighted average repurchase price of $13.85 per share, were reissued at an average price of $1.98 per share for option exercises and vested restricted share units.

Stock Options

The following table summarizes the Company's stock option activities for the six months ended December 31, 2015:



			Weighted
			Average
	Number of		Exercise Price		Aggregate
	Shares		Per Share		Intrinsic Value
Outstanding at June 30, 2015	2,836,217		$	10.77	$	1,410,538
Granted	—		$	—
Exercised	(277,916	)	$	7.05	$	458,006
Canceled or forfeited	(304,012	)	$	12.45
Outstanding at December 31, 2015	2,254,289		$	11.01	$	1,226,993

Information with respect to stock options outstanding and exercisable at December 31, 2015 is as follows:



	Options Outstanding				Options Vested and Exercisable
	Number Outstanding	Weighted-Average Remaining Contractual Life (years)	Weighted-Average Exercise Price		Number Exercisable	Weighted-Average Exercise Price
Total options outstanding	2,254,289	4.85	$	11.01	1,890,474	$	11.62
Options vested and expected to vest	2,222,601	4.80	$	11.05

Options expected to vest are the result of applying the pre-vesting forfeiture rate assumption to total outstanding options.

The fair value of stock options granted were estimated at the date of grant using the Black-Scholes option valuation model for the six months ended December 31, 2015 with the following weighted average assumptions:



	Six Months Ended December 31,
	2015
Volatility rate	39.91%
Risk-free interest rate	1.6% - 1.7%
Expected term	5.5 years
Dividend yield	0%

Historically, the Company estimates its expected volatility based on that of the publicly traded shares of industry peers over a period equivalent to the expected term of the stock awards granted. Beginning in July 2015, the Company's publicly traded shares history is also included in estimating the volatility rate.

Restricted Stock Units ("RSU")

The following table summarizes the Company's RSU activities for the six months ended December 31, 2015:



	Number of Restricted Stock Units		Weighted Average Grant Date Fair Value Per Share		Weighted Average Remaining Recognition Period (Years)	Aggregate Intrinsic Value
Nonvested at June 30, 2015	873,946		$	8.64	1.77	$	7,638,288
Granted	89,402		$	8.41
Vested	(87,676	)	$	9.35
Forfeited	(79,143	)	$	8.74
Nonvested at December 31, 2015	796,529		$	8.53	1.45	$	7,320,102
RSUs vested and expected to vest	701,811				1.35	$	6,449,648

The fair value of RSU is estimated based on the market price of the Company's share on the date of grant.

Employee Share Purchase Plan ("ESPP")

The assumptions used to estimate the fair values of common shares issued under the ESPP were as follows:




	Six Months Ended December 31,
	2015
Volatility rate	32.2%
Risk-free interest rate	0.3% - 0.9%
Expected term	1.3 years
Dividend yield	0%

Share-based Compensation Expense

The total share-based compensation expense related to stock options, ESPP and RSUs described above, recognized in the condensed consolidated statements of operations for the periods presented was as follows:



	Three Months Ended December 31,				Six Months Ended December 31,
	2015		2014		2015		2014
	(in thousands)				(in thousands)
Cost of goods sold	$	157	$	174	$	288	$	328
Research and development	264		293		457		499
Selling, general and administrative	664		810		1,129		1,552
	$	1,085	$	1,277	$	1,874	$	2,379

Total unrecognized stock-based compensation expense as of December 31, 2015 was $4.2 million, which includes estimated forfeitures and is expected to be recognized over a weighted-average period of 1.3 years.

Income Taxes	6 Months Ended
Income Taxes	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company recognized income tax expense of approximately $1.0 million for both of the three months ended December 31, 2015 and 2014, respectively. The Company recognized income tax expense of approximately $2.2 million and $2.1 million for the six months ended December 31, 2015 and 2014, respectively. The estimated effective tax rate for the three months ended December 31, 2015 was (170.3)% compared to (281.5)% for the three months ended December 31, 2014. The estimated effective tax rate for the six months ended December 31, 2015 was (164.3)% compared to 152.5% for the six months ended December 31, 2014. The changes in the effective tax rate and tax expense between the periods resulted primarily from changes in the mix of earnings in various geographic jurisdictions between the current and same period of last year. The Company files its income tax returns in the United States and in various foreign jurisdictions. The tax years 2001 to 2015 remain open to examination by U.S. federal and state tax authorities. The tax years 2009 to 2015 remain open to examination by foreign tax authorities. The Company's income tax returns are subject to examinations by the Internal Revenue Service and other tax authorities in various jurisdictions. In accordance with the guidance on the accounting for uncertainty in income taxes, the Company regularly assesses the likelihood of adverse outcomes resulting from these examinations to determine the adequacy of its provision for income taxes. These assessments can require considerable estimates and judgments. As of December 31, 2015, the gross amount of unrecognized tax benefits was approximately $6.6 million, of which $4.4 million, if recognized, would reduce the effective income tax rate in future periods. If the Company's estimate of income tax liabilities proves to be less than the ultimate assessment, then a further charge to expense would be required. If events occur and the payment of these amounts ultimately proves to be unnecessary, the reversal of the liabilities would result in tax benefits being recognized in the period when the Company determines the liabilities are no longer necessary. The Company does not anticipate any material changes to its uncertain tax positions during the next twelve months. On July 27, 2015, in Altera Corp. v. Commissioner, the U.S. Tax Court issued an opinion related to the treatment of stock-based compensation expense in an intercompany cost-sharing arrangement. A final decision has yet to be issued by the Tax Court due to other outstanding issues related to the case. At this time, the U.S. Department of the Treasury has not withdrawn the requirement to include stock-based compensation from its regulations. Due to the uncertainty surrounding the status of the current regulations, questions related to the scope of potential benefits, and the risk of the Tax Court’s decision being overturned upon appeal, the Company has not recorded any benefit as of December 31, 2015. The Company will continue to monitor ongoing developments and potential impacts to its financial statements.

Segment and Geographic Information

6 Months Ended

Dec. 31, 2015

Segment Reporting [Abstract]

Segment and Geographic Information

The Company is organized as, and operates in, one operating segment: the design, development and supply of power semiconductor products for computing, consumer electronics, communication and industrial applications. The chief operating decision-maker is the Chief Executive Officer. The financial information presented to the Company's Chief Executive Officer is on a consolidated basis, accompanied by information about revenue by customer and geographic region, for purposes of evaluating financial performance and allocating resources. The Company has one business segment, and there are no segment managers who are held accountable for operations, operating results and plans for products or components below the consolidated unit level. Accordingly, the Company reports as a single operating segment.

The Company sells its products primarily to distributors in the Asia Pacific region, who in turn sell these products to end customers. Because the Company's distributors sell their products to end customers which may have a global presence, revenue by geographical location is not necessarily representative of the geographical distribution of sales to end user markets.

The revenue by geographical location in the following tables is based on the country or region to which the products were shipped to:



	Three Months Ended December 31,				Six Months Ended December 31,
	2015		2014		2015		2014
	(in thousands)				(in thousands)
Hong Kong	$	69,904	$	70,278	$	140,357	$	145,525
China	7,922		8,823		16,938		19,780
South Korea	442		524		1,100		1,163
United States	784		881		1,501		1,564
Other Countries	773		822		1,368		1,513
	$	79,825	$	81,328	$	161,264	$	169,545

The following is a summary of revenue by product type:



	Three Months Ended December 31,				Six Months Ended December 31,
	2015		2014		2015		2014
	(in thousands)				(in thousands)
Power discrete	$	59,392	$	61,203	$	119,305	$	126,094
Power IC	16,400		16,109		$	33,913	$	35,265
Packaging and testing services	4,033		4,016		$	8,046	$	8,186
	$	79,825	$	81,328	$	161,264	$	169,545

Long-lived assets, net consisting of property, plant and equipment, by geographical area are as follows:



	December 31, 2015		June 30, 2015
	(in thousands)
China	$	66,907	$	71,618
United States	44,572		47,439
Other Countries	578		522
	$	112,057	$	119,579

- 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

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Reference 14: http://www.xbrl.org/2003/role/presentationRef
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+ Details

Commitments and Contingencies	6 Months Ended
Commitments and Contingencies	Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Purchase Commitments As of December 31, 2015 and June 30, 2015, the Company had approximately $39.0 million and $29.2 million, respectively, of outstanding purchase commitments primarily for purchases of semiconductor raw materials, wafers, spare parts and packaging and testing services, and approximately $5.2 million and $3.7 million, respectively, of capital commitments for the purchase of property and equipment. Contingencies and Indemnities The Company is currently not a party to any pending material legal proceedings. The Company has in the past, and may from time to time in the future, become involved in legal proceedings arising from the normal course of business activities. The semiconductor industry is characterized by frequent claims and litigation, including claims regarding patent and other intellectual property rights as well as improper hiring practices. Irrespective of the validity of such claims, the Company could incur significant costs in the defense of such claims and suffer adverse effects on its operations. The Company is a party to a variety of agreements that it has contracted with various third parties. Pursuant to these agreements, the Company may be obligated to indemnify another party to such an agreement with respect to certain matters. Typically, these obligations arise in the context of contracts entered into by the Company, under which the Company customarily agrees to hold the other party harmless against losses arising from a breach of representations and covenants related to such matters as title to assets sold, certain intellectual property rights, specified environmental matters and certain income taxes. In these circumstances, payment by the Company is customarily conditioned on the other party making a claim pursuant to the procedures specified in the particular contract, which procedures typically allow the Company to challenge the other party's claim. Further, the Company's obligations under these agreements may be limited in time and/or amount, and in some instances, the Company may have recourse against third parties for certain payments made by it under these agreements. The Company has not historically paid or recorded any material indemnifications and no accrual has been made at December 31, 2015 and June 30, 2015. The Company has agreed to indemnify its directors and certain employees as permitted by law and pursuant to its bye-laws, and has entered into indemnification agreements with its directors and executive officers. The Company has not recorded a liability associated with these indemnification arrangements, as it historically has not incurred any material costs associated with such indemnification obligations. Costs associated with such indemnification obligations may be mitigated by insurance coverage that the Company maintains. However, such insurance may not cover any, or may cover only a portion of, the amounts the Company may be required to pay. In addition, the Company may not be able to maintain such insurance coverage in the future.

The Company and Significant Accounting Policies (Policies)	6 Months Ended
	Dec. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Concentration Risk, Credit Risk, Policy [Policy Text Block]	The Company manages its credit risk associated with exposure to distributors and direct customers on outstanding accounts receivable through the application of credit approvals, credit ratings and other monitoring procedures. In some instances, the Company also obtains letters of credit from certain customers. Credit sales, which are mainly on credit terms of 30 to 60 days, are only made to customers who meet the Company's credit requirements, while sales to new customers or customers with low credit ratings are usually made on an advance payment basis. The Company considers its trade accounts receivable to be of good credit quality because its key distributors and direct customers have long-standing business relationships with the Company and the Company has not experienced any significant bad debt write-offs of accounts receivable in the past. The Company closely monitors the aging of accounts receivable from its distributors and direct customers, and regularly reviews their financial positions, when available.
Basis of Preparation	Basis of Preparation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“U.S. GAAP”) for interim financial information and with the instructions to Article 10 of Securities and Exchange Commission Regulation S-X, as amended. They do not include all information and footnotes necessary for a fair presentation of financial position, results of operations and cash flows in conformity with U.S. GAAP for complete financial statements. These condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and related notes contained in the Company’s Annual Report on Form 10-K for the fiscal year ended June 30, 2015. All significant intercompany balances and transactions have been eliminated in consolidation. In the opinion of management, all adjustments (consisting of normal recurring adjustments and accruals) considered necessary for a fair presentation of the results of operations for the period presented have been included in the interim periods. Operating results for the six months ended December 31, 2015 are not necessarily indicative of the results that may be expected for the fiscal year ending June 30, 2016. The condensed consolidated balance sheet at June 30, 2015 is derived from the audited financial statements included in the Company’s Annual Report on Form 10-K for the fiscal year ended June 30, 2015.
Use of Estimates	Use of Estimates The preparation of the condensed 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, share-based compensation, and useful lives for property, plant and equipment and intangible assets.
Fair Value of Financial Instruments	Fair Value of Financial Instruments The fair value of cash equivalents are 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.
Impairment of Long-Lived Assets [Policy Text Block]	Impairment of Long-Lived Assets Long-lived assets or asset groups are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset might not be recoverable. Factors that would necessitate an impairment assessment include a significant decline in the observable market value of an asset, a significant change in the extent or manner in which an asset is used, or any other significant adverse change that would indicate that the carrying amount of an asset or group of assets may not be recoverable. Where such factors indicate potential impairment, the recoverability of an asset or asset group is assessed by determining if the carrying value of the asset or asset group exceeds the sum of the projected undiscounted cash flows expected to result from the use and eventual disposition of the assets over the remaining economic life. The impairment loss is measured based on the difference between the carrying amount and estimated fair value.
Comprehensive Income (Loss)	Comprehensive Income (Loss) Comprehensive income (loss) is defined as the change in equity of a business enterprise during a period from transactions and other events and circumstances from non-owner sources. The Company's accumulated other comprehensive income (loss) consists of cumulative foreign currency translation adjustments. Total comprehensive income (loss) is presented in the condensed consolidated statements of comprehensive income (loss).
Recent Accounting Pronouncements	Recent Accounting Pronouncements In July 2015, the FASB issued No. 2015-11, Inventory - Simplifying the Measurement of Inventory ("ASU 2015-11"). ASU 2015-11 is additional guidance regarding the subsequent measurement of inventory by requiring inventory to be measured at the lower of cost and net realizable value. This guidance is effective for fiscal years and interim periods beginning after December 15, 2016. Early adoption is permitted. 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 April 2015, the FASB issued ASU No. 2015-03, Interest -Imputation of Interest(Subtopic 835-30): Simplifying the Presentation of Debt Issuance Costs. The amendments in this ASU require that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts and the accounting for debt issue costs under IFRS. The recognition and measurement guidance for debt issuance costs are not affected by the amendments in this ASU. ASU 2015-03 is effective for the annual period ending after December 15, 2015, and interim periods within those fiscal years. Early adoption of the amendments in this Update is permitted for financial statements that have not been previously issued. 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 February 2015, the FASB issued ASU No. 2015-2, “Consolidation (Topic 820): Amendments to the Consolidation Analysis.” ASU 2015-2 provides a revised consolidation model for all reporting entities to use in evaluating whether they should consolidate certain legal entities. All legal entities will be subject to reevaluation under this revised consolidation model. The revised consolidation model, among other things, (i) modifies the evaluation of whether limited partnerships and similar legal entities are VIEs or voting interest entities, (ii) eliminates the presumption that a general partner should consolidate a limited partnership, and (iii) modifies the consolidation analysis of reporting entities that are involved with VIEs through fee arrangements and related party relationships. ASU 2015-2 is effective for fiscal years, and interim reporting periods within those fiscal years, beginning after December 15, 2015. 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 August 2014, the FASB issued amended standards No. 2014-15, Presentation of Financial Statements - Going Concern ("ASU 2014-15"), to provide guidance about management’s responsibility to evaluate whether there is substantial doubt about an entity’s ability to continue as a going concern and to provide related footnote disclosures requirement. The amendments (1) provide a definition of the term substantial doubt, (2) require an evaluation for each annual and interim reporting period, (3) provide principles for considering the mitigating effect of management’s plans, (4) require certain disclosures when substantial doubt is alleviated as a result of consideration of management’s plans, (5) require an express statement and other disclosures when substantial doubt is not alleviated, and (6) require an assessment for a period of one year after the date that the financial statements are issued (or available to be issued). ASU 2014-15 is effective for the annual period ending after December 15, 2016, and for annual periods and interim periods thereafter. Early adoption is permitted. 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 May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers(“ASU 2014-09”). The standard provides companies with a single model for use in accounting for revenue arising from contracts with customers and supersedes current revenue recognition guidance, including industry-specific revenue guidance. The core principle of the model is to recognize revenue when control of the goods or services transfers to the customer, as opposed to recognizing revenue when the risks and rewards transfer to the customer under the existing revenue guidance. ASU 2014-09 is effective for annual reporting periods beginning after December 15, 2016. The guidance permits companies to either apply the requirements retrospectively to all prior periods presented, or apply the requirements in the year of adoption, through a cumulative adjustment. In July 2015, the FASB voted to amend ASU 2014-09 by approving a one-year deferral of the effective date as well as providing the option to early adopt the standard on the original effective date. In August 2015 the FASB issued ASU 2015-14, Revenue from Contracts with customers - Deferral of the Effective Date", that defers by one year the effective date of ASU 2014-09. The ASU is effective for annual reporting periods beginning after December 15, 2017, including interim periods within that reporting period. The Company is in the process of evaluating the timing of its adoption and the impact of adoption on its consolidated financial statements.

Net Income (Loss) Per Share (Tables)

6 Months Ended

Dec. 31, 2015

Earnings Per Share [Abstract]

Schedule of Earnings Per Share, Basic and Diluted

The following table presents the calculation of basic and diluted net loss per share:



	Three Months Ended December 31,						Six Months Ended December 31,
	2015			2014			2015			2014
	(in thousands, except per share data)
Numerator:
Net loss	$	(1,611	)	$	(1,297	)	$	(3,586	)	$	(733	)

Denominator:
Basic:
Weighted average number of common shares used to compute basic net loss per share	22,269			26,577			22,483			26,481
Diluted:
Weighted average number of common shares used to compute diluted net loss per share	22,269			26,577			22,483			26,481
Net loss per share:
Basic	$	(0.07	)	$	(0.05	)	$	(0.16	)	$	(0.03	)
Diluted	$	(0.07	)	$	(0.05	)	$	(0.16	)	$	(0.03	)

Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share

The following potential dilutive securities were excluded from the computation of diluted net loss per share as their effect would have been anti-dilutive:



	Three Months Ended December 31,		Six Months Ended December 31,
	2015	2014	2015	2014
	(in thousands)
Employee stock options and RSUs	3,299	3,694	3,458	3,758
ESPP to purchase common shares	551	462	369	441
Total potential dilutive securities	3,850	4,156	3,827	4,199

Concentration of Credit Risk and Significant Customers (Tables)

6 Months Ended

Dec. 31, 2015

Risks and Uncertainties [Abstract]

Schedules of Concentration of Risk, by Risk Factor

Summarized below are individual customers whose revenue or accounts receivable balances were 10% or higher than the respective total consolidated amounts:



	Three Months Ended December 31,				Six Months Ended December 31,
Percentage of revenue	2015		2014		2015		2014
Customer A	24.0	%	24.2	%	23.6	%	24.2	%
Customer B	39.6	%	37.1	%	37.8	%	38.4	%
Customer C	10.8	%	11.5	%	12.6	%	12.2	%



	December 31, 2015		June 30, 2015
Percentage of accounts receivable	December 31, 2015		June 30, 2015
Customer A	28.5	%	29.4	%
Customer B	18.4	%	27.7	%
Customer C	21.8	%	14.7	%

Balance Sheet Components (Tables)

6 Months Ended

Dec. 31, 2015

Balance Sheet Related Disclosures [Abstract]

Schedule of Accounts, Notes, Loans and Financing Receivable

Accounts receivable:



	December 31, 2015			June 30, 2015
	(in thousands)
Accounts receivable	$	42,489		$	58,249
Less: Allowance for price adjustments	(16,405		)	(19,438		)
Less: Allowance for doubtful accounts	(30		)	(30		)
Accounts receivable, net	$	26,054		$	38,781

Schedule of Inventory, Current

Inventories:



	December 31, 2015		June 30, 2015
	(in thousands)
Raw materials	$	18,917	$	19,423
Work in-process	33,015		31,269
Finished goods	9,170		13,483
	$	61,102	$	64,175

Property, Plant and Equipment

Property, plant and equipment, net:



	December 31, 2015			June 30, 2015
	(in thousands)
Land	$	4,877		$	4,877
Building	4,243			4,243
Manufacturing machinery and equipment	187,862			172,467
Equipment and tooling	12,125			11,261
Computer equipment and software	20,931			20,602
Office furniture and equipment	1,780			1,762
Leasehold improvements	28,098			27,568
	259,916			242,780
Less: Accumulated depreciation	(155,416		)	(141,883		)
	104,500			100,897
Equipment and construction in progress	7,557			18,682
Property, plant and equipment, net	$	112,057		$	119,579

Schedule of Other Assets, Noncurrent

Other long-term assets:



	December 31, 2015		June 30, 2015
	(in thousands)
Prepayments for property and equipment	$	324	$	692
Investment in a privately held company	100		100
Office leases deposits	1,814		1,215
Other	2		4
	$	2,240	$	2,011

Schedule of Accrued Liabilities

Accrued liabilities:



	December 31, 2015		June 30, 2015
	(in thousands)
Accrued compensation and benefit	$	6,387	$	5,600
Accrued vacation	1,771		1,830
Accrued bonuses	1,292		1,152
Warranty accrual	1,596		1,957
Stock rotation accrual	1,872		1,894
Accrued professional fees	1,631		1,402
ESPP payable	357		343
Customer deposits	830		149
Accrued inventory	268		697
Accrued facilities related expenses	1,469		1,367
Other accrued expenses	2,630		2,834
	$	20,103	$	19,225

Schedule of Product Warranty Liability

The activities in the warranty accrual, included in accrued liabilities, are as follows:



	Six Months Ended December 31,
	2015			2014
	(in thousands)
Beginning balance	$	1,957		$	1,346
Additions	747			910
Utilization	(1,108		)	(1,068		)
Ending balance	$	1,596		$	1,188

Stock Rotation Accrual

The activities in the stock rotation accrual, included in accrued liabilities, are as follows:



	Six Months Ended December 31,
	2015			2014
	(in thousands)
Beginning balance	$	1,894		$	1,645
Additions	3,120			2,820
Utilization	(3,142		)	(2,802		)
Ending balance	$	1,872		$	1,663

Schedule of Other Noncurrent Liabilities

Other Long-term liabilities:



	December 31, 2015		June 30, 2015
	(in thousands)
Deferred rent	$	851	$	953

Shareholders' Equity and Share-based Compensation (Tables)

6 Months Ended

Dec. 31, 2015

Share-based Compensation [Abstract]

Summary of Stock Option Activities

Stock Options

The following table summarizes the Company's stock option activities for the six months ended December 31, 2015:



			Weighted
			Average
	Number of		Exercise Price		Aggregate
	Shares		Per Share		Intrinsic Value
Outstanding at June 30, 2015	2,836,217		$	10.77	$	1,410,538
Granted	—		$	—
Exercised	(277,916	)	$	7.05	$	458,006
Canceled or forfeited	(304,012	)	$	12.45
Outstanding at December 31, 2015	2,254,289		$	11.01	$	1,226,993

Information with respect to stock options outstanding and exercisable at December 31, 2015 is as follows:



	Options Outstanding				Options Vested and Exercisable
	Number Outstanding	Weighted-Average Remaining Contractual Life (years)	Weighted-Average Exercise Price		Number Exercisable	Weighted-Average Exercise Price
Total options outstanding	2,254,289	4.85	$	11.01	1,890,474	$	11.62
Options vested and expected to vest	2,222,601	4.80	$	11.05

Options expected to vest are the result of applying the pre-vesting forfeiture rate assumption to total outstanding options.

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

The fair value of stock options granted were estimated at the date of grant using the Black-Scholes option valuation model for the six months ended December 31, 2015 with the following weighted average assumptions:



	Six Months Ended December 31,
	2015
Volatility rate	39.91%
Risk-free interest rate	1.6% - 1.7%
Expected term	5.5 years
Dividend yield	0%

Historically, the Company estimates its expected volatility based on that of the publicly traded shares of industry peers over a period equivalent to the expected term of the stock awards granted. Beginning in July 2015, the Company's publicly traded shares history is also included in estimating the volatility rate.

Restricted Stock Units Activity

Restricted Stock Units ("RSU")

The following table summarizes the Company's RSU activities for the six months ended December 31, 2015:



	Number of Restricted Stock Units		Weighted Average Grant Date Fair Value Per Share		Weighted Average Remaining Recognition Period (Years)	Aggregate Intrinsic Value
Nonvested at June 30, 2015	873,946		$	8.64	1.77	$	7,638,288
Granted	89,402		$	8.41
Vested	(87,676	)	$	9.35
Forfeited	(79,143	)	$	8.74
Nonvested at December 31, 2015	796,529		$	8.53	1.45	$	7,320,102
RSUs vested and expected to vest	701,811				1.35	$	6,449,648

The fair value of RSU is estimated based on the market price of the Company's share on the date of grant.

Schedule of Share-based Payment Award, Employee Stock Purchase Plan, Valuation Assumptions [Table Text Block]

Employee Share Purchase Plan ("ESPP")

The assumptions used to estimate the fair values of common shares issued under the ESPP were as follows:




	Six Months Ended December 31,
	2015
Volatility rate	32.2%
Risk-free interest rate	0.3% - 0.9%
Expected term	1.3 years
Dividend yield	0%

Share-based Compensation, Allocation of Recognized Period Costs

Share-based Compensation Expense

The total share-based compensation expense related to stock options, ESPP and RSUs described above, recognized in the condensed consolidated statements of operations for the periods presented was as follows:



	Three Months Ended December 31,				Six Months Ended December 31,
	2015		2014		2015		2014
	(in thousands)				(in thousands)
Cost of goods sold	$	157	$	174	$	288	$	328
Research and development	264		293		457		499
Selling, general and administrative	664		810		1,129		1,552
	$	1,085	$	1,277	$	1,874	$	2,379

Segment and Geographic Information (Tables)

6 Months Ended

Dec. 31, 2015

Segment Reporting [Abstract]

Schedule of Revenue from External Customers and Long-Lived Assets, by Geographical Areas

Long-lived assets, net consisting of property, plant and equipment, by geographical area are as follows:



	December 31, 2015		June 30, 2015
	(in thousands)
China	$	66,907	$	71,618
United States	44,572		47,439
Other Countries	578		522
	$	112,057	$	119,579

The revenue by geographical location in the following tables is based on the country or region to which the products were shipped to:



	Three Months Ended December 31,				Six Months Ended December 31,
	2015		2014		2015		2014
	(in thousands)				(in thousands)
Hong Kong	$	69,904	$	70,278	$	140,357	$	145,525
China	7,922		8,823		16,938		19,780
South Korea	442		524		1,100		1,163
United States	784		881		1,501		1,564
Other Countries	773		822		1,368		1,513
	$	79,825	$	81,328	$	161,264	$	169,545

Revenue from External Customers by Products and Services

The following is a summary of revenue by product type:



	Three Months Ended December 31,				Six Months Ended December 31,
	2015		2014		2015		2014
	(in thousands)				(in thousands)
Power discrete	$	59,392	$	61,203	$	119,305	$	126,094
Power IC	16,400		16,109		$	33,913	$	35,265
Packaging and testing services	4,033		4,016		$	8,046	$	8,186
	$	79,825	$	81,328	$	161,264	$	169,545

Net Income (Loss) Per Share - Basic and Diluted Income Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2015	Dec. 31, 2014
Numerator:
Net loss	$ (1,611)	$ (1,297)	$ (3,586)	$ (733)
Basic:
Weighted average number of common shares used to compute basic net loss per share	22,269	26,577	22,483	26,481
Effect of potentially dilutive securities:
Weighted average number of common shares used to compute diluted net loss per share	22,269	26,577	22,483	26,481
Net loss per share:
Basic (in dollars per share)	$ (0.07)	$ (0.05)	$ (0.16)	$ (0.03)
Diluted (in dollars per share)	$ (0.07)	$ (0.05)	$ (0.16)	$ (0.03)

- Definition

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

+ References + Details

- Definition

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

+ References + Details

Net Income (Loss) Per Share - Potential Dilutive Shares (Details) - shares shares in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2015	Dec. 31, 2014
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential dilutive securities (in shares)	3,850	4,156	3,827	4,199
Employee stock options and RSUs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential dilutive securities (in shares)	3,299	3,694	3,458	3,758
ESPP to purchase common shares
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential dilutive securities (in shares)	551	462	369	441

Concentration of Credit Risk and Significant Customers - (Details)	3 Months Ended			6 Months Ended
	Dec. 31, 2015	Jun. 30, 2015	Dec. 31, 2014	Dec. 31, 2015	Dec. 31, 2014
Minimum [Member]
Concentration Risk
Terms of credit sales, (in days)				30 days
Maximum [Member]
Concentration Risk
Terms of credit sales, (in days)				60 days
Customer A \| Sales Revenue, Goods, Net \| Customer Concentration Risk
Concentration Risk
Customers greater than 10% of total	24.00%		24.20%	23.60%	24.20%
Customer A \| Accounts Receivable \| Customer Concentration Risk
Concentration Risk
Customers greater than 10% of total	28.50%	29.40%
Customer B \| Sales Revenue, Goods, Net \| Customer Concentration Risk
Concentration Risk
Customers greater than 10% of total	39.60%		37.10%	37.80%	38.40%
Customer B \| Accounts Receivable \| Customer Concentration Risk
Concentration Risk
Customers greater than 10% of total	18.40%	27.70%
Customer C \| Sales Revenue, Goods, Net \| Customer Concentration Risk
Concentration Risk
Customers greater than 10% of total	10.80%		11.50%	12.60%	12.20%
Customer C \| Accounts Receivable \| Customer Concentration Risk
Concentration Risk
Customers greater than 10% of total	21.80%	14.70%

Balance Sheet Components - Accounts receivable (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Jun. 30, 2015
Balance Sheet Related Disclosures [Abstract]
Accounts receivable	$ 42,489	$ 58,249
Less: Allowance for price adjustments	(16,405)	(19,438)
Less: Allowance for doubtful accounts	(30)	(30)
Accounts receivable, net	$ 26,054	$ 38,781

Balance Sheet Components - Inventories (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Jun. 30, 2015
Balance Sheet Related Disclosures [Abstract]
Raw materials	$ 18,917	$ 19,423
Work in-process	33,015	31,269
Finished goods	9,170	13,483
Inventory, net	$ 61,102	$ 64,175

Balance Sheet Components - Property, plant, and equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Jun. 30, 2015
Property, Plant and Equipment [Line Items]
Property, plant, and equipment excluding equipment and construction In progress, gross	$ 259,916	$ 242,780
Less: Accumulated depreciation	(155,416)	(141,883)
Property, plant and equipment excluding equipment and construction in progress, net	104,500	100,897
Equipment and construction in progress	7,557	18,682
Property, plant and equipment, net	112,057	119,579
Land
Property, Plant and Equipment [Line Items]
Property, plant, and equipment excluding equipment and construction In progress, gross	4,877	4,877
Building
Property, Plant and Equipment [Line Items]
Property, plant, and equipment excluding equipment and construction In progress, gross	4,243	4,243
Manufacturing machinery and equipment
Property, Plant and Equipment [Line Items]
Property, plant, and equipment excluding equipment and construction In progress, gross	187,862	172,467
Equipment and tooling
Property, Plant and Equipment [Line Items]
Property, plant, and equipment excluding equipment and construction In progress, gross	12,125	11,261
Computer equipment and software
Property, Plant and Equipment [Line Items]
Property, plant, and equipment excluding equipment and construction In progress, gross	20,931	20,602
Office furniture and equipment
Property, Plant and Equipment [Line Items]
Property, plant, and equipment excluding equipment and construction In progress, gross	1,780	1,762
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property, plant, and equipment excluding equipment and construction In progress, gross	$ 28,098	$ 27,568

Balance Sheet Components - Other long term assets (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Jun. 30, 2015
Balance Sheet Related Disclosures [Abstract]
Prepayments for property and equipment	$ 324	$ 692
Investment in a privately held company	100	100
Office leases deposits	1,814	1,215
Other Assets, Miscellaneous, Noncurrent	2	4
Other long-term assets	$ 2,240	$ 2,011

Balance Sheet Components - Accrued liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Jun. 30, 2015	Dec. 31, 2014	Jun. 30, 2014
Balance Sheet Related Disclosures [Abstract]
Accrued compensation and benefit	$ 6,387	$ 5,600
Accrued vacation	1,771	1,830
Accrued bonuses	1,292	1,152
Warranty accrual	1,596	1,957	$ 1,188	$ 1,346
Stock rotation accrual	1,872	1,894	$ 1,663	$ 1,645
Accrued professional fees	1,631	1,402
ESPP payable	357	343
Customer deposits	830	149
Accrued inventory	268	697
Accrued facilities related expenses	1,469	1,367
Other accrued expenses	2,630	2,834
Accrued liabilities	$ 20,103	$ 19,225

Balance Sheet Components - Product Warranty Accrual (Details) - USD ($) $ in Thousands	6 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Movement in Standard and Extended Product Warranty, Increase (Decrease) [Roll Forward]
Beginning balance	$ 1,957	$ 1,346
Additions	747	910
Utilization	(1,108)	(1,068)
Ending balance	$ 1,596	$ 1,188

Balance Sheet Components - Other Long Term Liability (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Jun. 30, 2015
Balance Sheet Related Disclosures [Abstract]
Deferred rent	$ 851	$ 953
Other long term liabilities	$ 851	$ 953

Balance Sheet Components - Stock Rotation Accrual (Details) - USD ($) $ in Thousands	6 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Stock Rotation Accrual Increae (Decrease) [Roll Forward]
Beginning balance	$ 1,894	$ 1,645
Additions	3,120	2,820
Utilization	(3,142)	(2,802)
Ending balance	$ 1,872	$ 1,663

Shareholders' Equity and Share-based Compensation - Shares Repurchase (Details) - USD ($) $ / shares in Units, $ in Millions		6 Months Ended	62 Months Ended
	Jul. 07, 2015	Dec. 31, 2015	Dec. 31, 2015	Jul. 08, 2015	Jun. 30, 2015	Jun. 07, 2015	Apr. 30, 2015	Mar. 31, 2015
Class of Stock [Line Items]
Shares Repurchase Program Remaining Balance				$ 18.2			$ 50.0	$ 17.8
Treasury stock acquired, shares repurchased (in shares)		4,491,375	5,518,969
Treasury Stock, Value, Acquired, Cost Method		$ 40.0	$ 48.9
Treasury stock acquired, average price per share (in dollars per share)		$ 8.90	$ 8.87
Treasury stock, Acquired, Fees and related expenses		$ 0.3
Treasury Stock, Shares, Retired			0
Treasury Stock Reissued, Average Price Per Share			$ 1.98
Treasury Stock Reissued
Class of Stock [Line Items]
Treasury stock acquired, average price per share (in dollars per share)			$ 13.85
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures (in shares)			32,766
Dutch Auction Tender Offer [Member] \| Common Stock [Member]
Class of Stock [Line Items]
Share repurchase program, authorized amount (USD in Millions)						$ 30.0
Treasury stock acquired, shares repurchased (in shares)	3,296,703
Treasury Stock, Value, Acquired, Cost Method	$ 30.0
Treasury Stock, Shares, Acquired, Represent Percentage Of The Company's Common Shares Issued And Outstanding					12.53%
Treasury stock acquired, average price per share (in dollars per share)	$ 9.10
Dutch Auction Tender Offer [Member] \| Minimum [Member] \| Common Stock [Member]
Class of Stock [Line Items]
Stock Repurchase Program, Authorized Cost Per Share						$ 8.50
Dutch Auction Tender Offer [Member] \| Maximum [Member] \| Common Stock [Member]
Class of Stock [Line Items]
Stock Repurchase Program, Authorized Cost Per Share						$ 9.20

Shareholders' Equity and Share-based Compensation - Share-based Compensation (Details) - USD ($)	6 Months Ended
	Dec. 31, 2015	Jun. 30, 2015
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding at June 30, 2015 (in shares)	2,836,217
Granted (in shares)	0
Exercised (in shares)	(277,916)
Canceled or forfeited (in shares)	(304,012)
Outstanding at September 30, 2015 (in shares)	2,254,289
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Outstanding at June 30, 2015 (in dollars per share)	$ 10.77
Granted (in dollars per share)	0
Exercised (in dollars per share)	7.05
Canceled or forfeited (in dollars per share)	12.45
Outstanding at September 30, 2015 (in dollars per share)	$ 11.01
Options Outstanding Aggregate Intrinsic Value	$ 1,226,993	$ 1,410,538
Options Exercised Aggregate Intrinsic Value	$ 458,006
Employee Share Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Volatility Rate	32.20%
Expected Term	1 year 3 months 18 days
Expected Dividend Rate	0.00%
Employee Share Purchase Plan [Member] \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk Free Interest Rate	0.30%
Employee Share Purchase Plan [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk Free Interest Rate	0.90%
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Volatility Rate	39.91%
Expected Term	5 years 6 months
Expected Dividend Rate	0.00%
Stock Options [Member] \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk Free Interest Rate	1.60%
Stock Options [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk Free Interest Rate	1.70%

Shareholders' Equity and Share-based Compensation - Stock Options Outstanding and Exercisable (Details) - $ / shares	6 Months Ended
	Dec. 31, 2015	Jun. 30, 2015
Share-based Compensation [Abstract]
Options, Number Outstanding (in shares)	2,254,289	2,836,217
Options, Weighted-Average Remaining Contractual Life (in years)	4 years 10 months 6 days
Options, Weighted-Average Exercise Price (in dollars per share)	$ 11.01	$ 10.77
Options, Number Exercisable (in shares)	1,890,474
Options, Weighted-Average Exercise Price (in dollars per share)	$ 11.62
Options vested and expected to vest, Number Outstanding (in shares)	2,222,601
Options vested and expected to vest, Weighted Average Remaining Contractual Life (in years)	4 years 9 months 18 days
Options vested and expected to vest, Weighted Average Exercise Price (in dollars per share)	$ 11.05

Shareholders' Equity and Share-based Compensation - Restricted Stock Activity (Details) - USD ($)	3 Months Ended		6 Months Ended
	Dec. 31, 2015	Jun. 30, 2015	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Weighted Average Remaining Recognition Period (Years)	1 year 3 months 18 days
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Nonvested at June 30, 2015			873,946
Granted			89,402
Vested			(87,676)
Forfeited			(79,143)
Nonvested at December 31, 2015	796,529	873,946	796,529
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Nonvested at June 30, 2015			$ 8.64
Granted			8.41
Vested			9.35
Forfeited			8.74
Nonvested at December 31, 2015	$ 8.53	$ 8.64	$ 8.53
Weighted Average Remaining Recognition Period (Years)	1 year 5 months 12 days	1 year 9 months 7 days
RSUs Nonvested Aggregate Intrinsic Value	$ 7,320,102	$ 7,638,288	$ 7,320,102
RSUs vested and expected to vest, Outstanding (in shares)	701,811		701,811
RSUs vested and expected to vest, Weighted Average Remaining Recognition Period (in years)	1 year 4 months 6 days
RSUs vested and expected to vest, Aggregate Intrinsic Value	$ 6,449,648		$ 6,449,648

Shareholders' Equity and Share-based Compensation - Share-based Compensation Expenses (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2015	Dec. 31, 2014
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated share-based compensation expense	$ 1,085	$ 1,277	$ 1,874	$ 2,379
Unrecognized compensation expense	$ 4,200		4,200
Recognition period of share-based compensation expense (in years)	1 year 3 months 18 days
Cost of goods sold
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated share-based compensation expense	$ 157	174	288	328
Research and development
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated share-based compensation expense	264	293	457	499
Selling, general and administrative
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated share-based compensation expense	$ 664	$ 810	$ 1,129	$ 1,552

Income Taxes - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
Income Taxes - Narrative (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Income tax expense	$ 1,015	$ 957	$ 2,229	$ 2,128
Estimated effective income tax rate	(170.30%)	(281.50%)	(164.30%)	152.50%
Unrecognized tax benefits	$ 6,600		$ 6,600
Unrecognized tax benefit that would impact effective tax rate	$ 4,400		$ 4,400

Segment and Geographic Information - Revenue by Location and Product Type (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2015	Dec. 31, 2014
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 79,825	$ 81,328	$ 161,264	$ 169,545
Power discrete
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	59,392	61,203	119,305	126,094
Power IC
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	16,400	16,109	33,913	35,265
Packaging and testing services
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	4,033	4,016	8,046	8,186
Hong Kong
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	69,904	70,278	140,357	145,525
China
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	7,922	8,823	16,938	19,780
South Korea
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	442	524	1,100	1,163
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	784	881	1,501	1,564
Other Countries
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 773	$ 822	$ 1,368	$ 1,513

Segment and Geographic Information - Long-lived Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Jun. 30, 2015
Revenues from External Customers and Long-Lived Assets [Line Items]
Property, plant and equipment, net	$ 112,057	$ 119,579
China
Revenues from External Customers and Long-Lived Assets [Line Items]
Property, plant and equipment, net	66,907	71,618
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Property, plant and equipment, net	44,572	47,439
Other Countries
Revenues from External Customers and Long-Lived Assets [Line Items]
Property, plant and equipment, net	$ 578	$ 522

Segment and Geographic Information - Narratives (Details)	6 Months Ended
	Dec. 31, 2015 Segment
Segment Reporting [Abstract]
Number of operating segments	1
Number of reportable segments	1

Commitments and Contingencies - Purchase Commitments (Details) - USD ($) $ in Millions	Dec. 31, 2015	Jun. 30, 2015
Raw materials, wafers, and packaging and testing services puchase commitments
Purchase Commitment, Excluding Long-term Committment [Line Items]
Purchase commitment, amount	$ 39.0	$ 29.2
Property and equipment purchase commitments
Purchase Commitment, Excluding Long-term Committment [Line Items]
Purchase commitment, amount	$ 5.2	$ 3.7

Commitments and Contingencies - Guarantees (Details) - USD ($)	Dec. 31, 2015	Jun. 30, 2015
Indemnification Agreement
Loss Contingencies [Line Items]
Indemnifications accrual	$ 0	$ 0