MP28251

20V, 4A Synchronous

Step-Down Converter

MP28251 Rev. 1.16

www.MonolithicPower.com

1

4/17/2013

MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.

© 2013 MPS. All Rights Reserved.

The Future of Analog IC Technology

DESCRIPTION

The MP28251 is a synchronous, rectified, step-

down, switch-mode converter with internal

power MOSFETs. It offers a very compact

solution to achieve a 4A continuous output

current over a wide input supply range with

excellent

load

and

line

regulation.

The

MP28251 has synchronous mode operation for

higher efficiency over the output current load

range.

Current-mode

operation

provides

a

fast

transient response and eases loop stabilization.

Full protection features include over-current

protection and thermal shutdown.

The MP28251 requires a minimal number of

readily-available standard external components

and is available in a space saving 2mm×3mm

14-pin QFN package.

FEATURES

 Wide 4.75V-to-20V Operating Input Range

 4A Output Current

 Programmable Switching Frequency

 Programmable EN Delay

 Frequency SYNC from 300kHz to 2MHz

External Clock

 Low Power Mode Selectable by an External

Signal

 External Soft Start

 OCP and Thermal Shutdown

 Available in a 14-pin QFN2×3 Package

APPLICATIONS

 DSL Modems

 Cable Modems

 Set Top Boxes

All MPS parts are lead-free and adhere to the RoHS directive. For MPS green

status, please visit MPS website under Products, Quality Assurance page.

“MPS” and “The Future of Analog IC Technology” are registered trademarks of

Monolithic Power Systems, Inc.

TYPICAL APPLICATION

MP28251

VCC

U1

R1

30.1k

R2

10k

R5

10

CSS

22nF

3.3V

VOUT

VIN

VCC

EN

ON

OFF

LPM

CDELAY

47nF

RFREQ

30.1k

EN

LPM

FREQ/SYNC

GND

SS

FB

SW

BS

IN

FREQ/SYNC

RT

0