MONOLITHIC POWER SYSTEMS INC — Director's Dealing 2013

Feb 8, 2013

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: MONOLITHIC POWER SYSTEMS INC (MPWR)
CIK: 0001280452
Period of Report: 2013-02-06

Reporting Person: Hsing Michael (Director, CEO)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2013-02-06	Common Stock	S	31272.0	$22.8889	Disposed	601169.0	Direct
2013-02-06	Common Stock	S	39229.0	$22.8889	Disposed	561940.0	Direct
2013-02-06	Common Stock	A	7064.0	$0.0	Acquired	569004.0	Direct
2013-02-07	Common Stock	S	3646.0	$23.7	Disposed	565358.0	Direct

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock	465566.0	Indirect
Common Stock	133040.0	Indirect
Common Stock	33000.0	Indirect
Common Stock	133040.0	Indirect

Footnotes

F1: Shares sold to pay tax obligations resulting from the vesting of performance units (restricted stock units) originally granted on February 25, 2010. The Performance was met and the shares were released per board approval on February 5, 2013.

F2: Shares sold to pay tax obligations resulting from the vesting of performance units (restricted stock units) originally granted on February 8, 2011. The Performance was met and the shares were released per board approval on February 5, 2013.

F3: Equitable stock dividend adjustment approved by the Board of Director as a result of dividend Payment to shareholders on December 28, 2012. Stock dividends will release according to the same vesting schedule as the original grants.

F4: Shares sold to pay tax obligations resulting from the release of restricted stock units.