MP1570

3A, 23V, 340KHz Synchronous Rectified

Step-Down Converter

MP1570 Rev. 1.5

www.MonolithicPower.com

1

1/31/2006

MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.

© 2006 MPS. All Rights Reserved.

The Future of Analog IC Technology

TM

TM

DESCRIPTION

The MP1570 is a monolithic synchronous buck

regulator.

The

device

integrates

100mΩ

MOSFETS that provide 3A continuous load

current over a wide operating input voltage of

4.75V to 23V. Current mode control provides

fast transient response and cycle-by-cycle

current limit.

An adjustable soft-start prevents inrush current

at turn-on. In shutdown mode, the output is

actively discharged by transferring energy in the

output capacitor to the input capacitor, dropping

the supply current to 1µA.

This device, available in an 8-pin SOIC

package, provides a very compact system

solution with minimal reliance on external

components.

EVALUATION BOARD REFERENCE

Board Number

Dimensions

EV1570DN-00A

2.0”X x 1.5”Y x 0.5”Z

FEATURES

• 3A Output Current

• Wide 4.75V to 23V Operating Input Range

• Integrated 100mΩ Power MOSFET Switches

• Output Adjustable from 1.23V to 20V

• Up to 95% Efficiency

• Programmable Soft-Start

• Stable with Low ESR Ceramic Output Capacitors

• Fixed 340KHz Frequency

• Cycle-by-Cycle Over Current Protection

• Input Under Voltage Lockout

• Thermally Enhanced 8-Pin SOIC Package

APPLICATIONS

• Distributed Power Systems

• Pre-Regulator for Linear Regulators

• Notebook Computers

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

Power Systems, Inc.

TYPICAL APPLICATION

INPUT

4.75V to 23V

OUTPUT

3.3V

3A

C3

3.3nF

D1

B130

(optional)

C5

10nF

MP1570

BS

IN

1

2

3

5

6

4

8

7

FB

SW

SS

GND

COMP

EN

C6

(optional)

MP1570_TAC01

100

95

90

85

80

75

70

65

60

0

0.5 1.0 1.5 2.0 2.5 3.0 3.5

LOAD CURRENT (A)

MP1570-EC02

Efficiency vs.

Load Current