ALPHA & OMEGA SEMICONDUCTOR Ltd — Director's Dealing 2012

May 1, 2012

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: ALPHA & OMEGA SEMICONDUCTOR Ltd (AOSL)
CIK: 0001387467
Period of Report: 2012-04-26

Reporting Person: Chang Mike F (Director, Chief Executive Officer, 10% Owner)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2012-04-26	Common Shares	A	12533	—	Acquired	4158244	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2012-04-26	Employee Share Option (right to buy)	$9.90	A	56400	Acquired	2022-04-25	Common Share (56400)	Direct

Footnotes

F1: Represents shares of the Issuer's common shares underlying restricted stock units (RSUs) awarded to the Reporting Person. The RSUs will vest in a series of forty-eight (48) successive equal monthly installments measured from April 26, 2012, provided the Reporting Person remains in the Issuer's service through each such date.

F2: Includes (i) 12,533 shares of the Issuer's common shares subject to the reported RSU award, and (ii) 875 shares acquired under the Issuer's Employee Stock Purchase Plan on November 14, 2011.

F3: The option will vest and become exercisable for the underlying common shares in a series of forty-eight (48) successive equal monthly installments measured from April 26, 2012, provided the Reporting Person remains in the Issuer's service through each such date.