MP28256

21V, 3A 500kHz Synchronous

Step-Down Coverter

MP28256 Rev. 1.0

www.MonolithicPower.com

1

11/3/2011

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© 2011 MPS. All Rights Reserved.

The Future of Analog IC Technology

DESCRIPTION

The MP28256 is a synchronous rectified step-

down switch mode converter with built in

internal power MOSFETs. It offers a very

compact solution to achieve 3A continuous

output current over a wide input supply range

with excellent load and line regulation. The

MP28256 has synchronous mode operation for

higher efficiency over output current load range.

Current mode operation provides fast transient

response and eases loop stabilization. Full

protection features include OCP and thermal

shut down.

The MP28256 requires a minimum number of

readily available standard external components

and is available in a space saving QFN14

(3x4mm) package.

FEATURES

 Wide 4.5V to 21V Operating Input Range

 0.6V internal reference with 2% accuracy

 3A Output Current

 Low Rds(ON) Internal Power MOSFETs

 Fixed 500kHz Switching Frequency

 Frequency SYNC from 300kHz to 2MHz

External Clock

 External Soft Start

 OCP and Thermal Shutdown

 Separate EN and SYNC pins

 Available in a QFN14 (3x4mm) Package.

APPLICATIONS

 DSL Modems

 Cable Modems

 Set Top Boxes

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“MPS” and “The Future of Analog IC Technology” are Registered Trademarks of

Monolithic Power Systems, Inc.

TYPICAL APPLICATION

Efficiency vs. Load Current

LOAD CURRENT (A)

0

10

20

30

40

50

60

70

80

90

100

00.5

11.5

22.5

33.5

V

V

V