MONOLITHIC POWER SYSTEMS INC — Director's Dealing 2012

Jan 10, 2012

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: MONOLITHIC POWER SYSTEMS INC (MPWR)
CIK: 0001280452
Period of Report: 2012-01-10

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

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2012-01-10	Common Stock	M	14000.0	$1.2	Acquired	136124.0	Direct
2012-01-10	Common Stock	S	14000.0	$15.5951	Disposed	122124.0	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2012-01-10	Incentive Stock Option (right to buy)	$1.2	M	14000.0	Disposed	2013-09-11	Common Stock (14000.0)	Direct

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock	153556.0	Indirect
Common Stock	113900.0	Indirect
Common Stock	26000.0	Indirect
Common Stock	26000.0	Indirect

Footnotes

F1: In accordance with the reporting person's 10b5-1 trading plan.

F2: 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 $15.52 to $15.6225. 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.