SEC Form 3

FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES 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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1. Name and Address of Reporting Person* BAVP, L.P. (Last) (First) (Middle) 950 TOWER LANE SUITE 700 (Street) FOSTER CITY CA 94404 (City) (State) (Zip)	2. Date of Event Requiring Statement (Month/Day/Year) 11/18/2004	3. Issuer Name and Ticker or Trading Symbol MONOLITHIC POWER SYSTEMS INC [ MPWR ]
		4. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director X 10% Owner Officer (give title below) Other (specify below)	5. 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 Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Series D Convertible Preferred Stock	(1)	(1)	Common Stock	2,798,185	(2)	D

Explanation of Responses:

1. The shares of Series D Convertible Preferred Stock are immediately convertible and do not have an expiration date.

2. The shares of Series D Convertible Preferred Stock at a ration of 1 share of Common Stock for each share of Series D Convertible Preferred Stock upon the closing of the Issuer's initial public offering at a per share offering price of $8.23 or above. At any offering price below $8.23, the conversion ratio is determined as a function of the difference between the offering price and $8.23, but in no event would such ratio exceed 1.058964964 shares of Common Stock for each share of Series D Convertible Preferred Stock.

Remarks:

The voting and disposition of these shares held by BAVP, LP is determined by BA Venture Partners VI, LLC, the ultimate general partner of BAVP, LP. Such decisions by BA Venture Partners VI, LLC are, in turn, determined by a majority-in-interest of its five managing members: Kate Mitchell, Lou Bock, Mark Brooks, John Dougery and Rory O'Driscoll. Jim Jones is one of the members of BA Venture Partners VI, LLC and as such has a pecuniary interest in a portion of these shares, but has no voting or investment power with respect to such shares. Mr. Jones disclaims beneficial ownership of these shares, except to the extent of his proportionate pecuniary interest therein.

	/s/ Kate D. Mitchell, Managing Director of BA Venture Partners VI, LLC, the general partner of BAVP, LP	11/18/2004
	** 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 5 (b)(v).
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