MONOLITHIC POWER SYSTEMS INC — Director's Dealing 2011

Sep 19, 2011

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: MONOLITHIC POWER SYSTEMS INC (MPWR)
CIK: 0001280452
Period of Report: 2011-09-19

Reporting Person: Xiao Deming (Pres. of MPS Asia Operations)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2011-08-15	Common Stock	J	619	$10.6505	Acquired	22283	Indirect
2011-09-19	Common Stock	S	143	$12.3806	Disposed	22140	Indirect

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock	145547	Direct

Footnotes

F1: Acquired through the Company's qualified ESPP program.

F2: Represent shares owned by the reporting person's spouse.

F3: Shares sold to pay tax obligations resulting from the vesting of restricted stock units.