MONOLITHIC POWER SYSTEMS INC — Director's Dealing 2014

Feb 6, 2014

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: MONOLITHIC POWER SYSTEMS INC (MPWR)
CIK: 0001280452
Period of Report: 2014-02-04

Reporting Person: Tseng Saria (VP & General Counsel)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2014-02-04	Common Stock	S	1477.0	$32.19	Disposed	42375	Direct
2014-02-04	Common Stock	A	46382.0	$0.0	Acquired	88757	Direct
2014-02-04	Common Stock	A	10944.0	$0.0	Acquired	99701	Direct
2014-02-05	Common Stock	S	8824.0	$31.1686	Disposed	90877	Direct
2014-02-06	Common Stock	S	504.0	$31.27	Disposed	90373	Direct
2014-02-06	Common Stock	S	1992.0	$32.0	Disposed	88381	Direct

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock	2000	Indirect

Footnotes

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

F2: On February 14, 2012, the reporting person was granted a target of 25,665 shares of restricted stock units subject to satisfaction of pre-determined, performance-based vesting criteria. On February 4, 2014, the Company's Board of Directors determined that those performance criteria for the restricted stock units had been satisfied, which resulted in 18,632 additional shares being achieved and granted to the reporting person. In addition, 2,085 shares were granted as a result of an equitable stock dividend adjustment approved by the Board of Directors on December 28, 2012. Of the restricted stock units that were awarded, 23,192 will vest immediately and 23,190 will vest quarterly in the next two years.

F3: 1/8 of the Restricted Stock Units shall vest quarterly following the Vesting Commencement Date, provided that the Grantee continues to be a Service Provider from the Grant Date through each applicable vesting date. Additionally, 32,831 shares of Restricted Stock Units were granted and shall be subject to satisfaction of performance-based vesting criteria based on achievement of certain long term Company performance targets, as determined by the Compensation Committee of the Company, and additional time vesting subsequent to the achievement of those performance targets, provided that the Grantee continues to be a Service Provider from the grant date through each applicable vesting date.

F4: In accordance with the reporting person's 10b5-1 trading plan.