SEC FORM 4

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

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Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person^*

Sciammas Maurice

(Last)

(First)

(Middle)

79 GREAT OAKS BLVD

(Street)

SAN JOSE

95119

(City)

(State)

(Zip)

2. Issuer Name and Ticker or Trading Symbol
MONOLITHIC POWER SYSTEMS INC [ MPWR ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director	10% Owner
X	Officer (give title below)	Other (specify below)
	Sr. V.P.of Sales and Marketing

3. Date of Earliest Transaction (Month/Day/Year)
02/04/2014

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	Amount	(A) or (D)	Price		6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
Common Stock	02/04/2014		S⁽¹⁾		1,620	D	$32.19	95,926	D
Common Stock	02/04/2014		S⁽²⁾		2,241	D	$32.19	93,685	D
Common Stock	02/04/2014		A		46,382⁽³⁾	A	$0.0	140,067	D
Common Stock	02/04/2014		A		10,944⁽⁴⁾	A	$0.0	151,011	D
Common Stock	02/05/2014		S⁽¹⁾		8,828	D	$31.1686	142,183	D
Common Stock	02/06/2014		S⁽¹⁾		502	D	$31.27	141,681	D
Common Stock	02/06/2014		S⁽²⁾		829	D	$31.27	140,852	D
Common Stock								12,746	I	by Family Trust

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	8. Price of Derivative Security (Instr. 5)		10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)

Explanation of Responses:

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

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

3. 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.

4. 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.

	By: Saria Tseng For: Maurice Sciammas	02/06/2014
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
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