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: Dotz Mary (Chief Financial Officer)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2012-04-26	Common Shares	A	4533	—	Acquired	4533	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2012-04-26	Employee Share Option (right to buy)	$9.9	A	150000	Acquired	2022-04-25	Common Share (150000)	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: The option will vest and become exercisable with respect to one-forth (1/4) of the underlying shares on the first anniversary of March 1, 2012, and thereafter the balance of the option shares will vest and become exercisable in a series of thirty-six (36) successive equal monthly installments, provided the Reporting Person remains in the Issuer's service through each such date.