MONOLITHIC POWER SYSTEMS INC — Director's Dealing 2011

Mar 30, 2011

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: MONOLITHIC POWER SYSTEMS INC (MPWR)
CIK: 0001280452
Period of Report: 2011-03-30

Reporting Person: Ueunten Paul (Sr. V.P. Design Engineering)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2011-02-15	Common Stock	J	1066	$13.1325	Acquired	126656	Direct
2011-03-30	Common Stock	M	13000	$1.2	Acquired	139656	Direct
2011-03-30	Common Stock	S	13000	$14.176	Disposed	126656	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2011-03-30	Incentive Stock Option (right to buy)	$1.2	M	13000	Disposed	2012-07-17	Common Stock (13000)	Direct

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock	153556	Indirect
Common Stock	113900	Indirect
Common Stock	26000	Indirect
Common Stock	26000	Indirect

Footnotes

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

F2: In accordance with the reporting person's 10b5-1 trading plan.

F3: The price is the weighted average sale price for the transactions reported on this line. The prices for the transactions reported on this line range from $14.1325 to $14.27. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price.