MONOLITHIC POWER SYSTEMS INC — Director's Dealing 2010

Nov 12, 2010

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: MONOLITHIC POWER SYSTEMS INC (MPWR)
CIK: 0001280452
Period of Report: 2010-11-10

Reporting Person: Sciammas Maurice (Sr. V.P.of Sales and Marketing)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2010-11-10	Common Stock	S	313	$15.4295	Disposed	77668	Direct
2010-11-10	Common Stock	S	884	$15.4293	Disposed	76784	Direct
2010-11-11	Common Stock	S	991	$15.8308	Disposed	75793	Direct

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock	95934	Indirect
Common Stock	24671	Indirect
Common Stock	24671	Indirect

Footnotes

F1: Shares sold to pay tax obligations resulting from the vesting of restricted stock units.

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 $15.76 to $15.92. 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.

F4: Shares held by Sciammas Family Living Trust, Maurice Sciammas and Christina Sciammas, Trustees

F5: Shares held by Christina Sciammas 2004 Trust, Christina Sciammas and Maurice Sciammas, Trustees

F6: Shares held by Maurice Sciammas 2004 Trust, Maurice Sciammas and Christina Sciammas, Trustees