MP1543

1.5A, 500KHz Synchronous

Rectified Step-up Converter

MP1543 Rev. 1.0

www.MonolithicPower.com

1

1/11/2006

MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.

© 2006 MPS. All Rights Reserved.

The Future of Analog IC Technology

TM

TM

DESCRIPTION

The MP1543 is a highly efficient, synchronous,

fixed frequency, current-mode step-up converter

with output to input disconnect, inrush current

limiting and internal soft-start. It includes an error

amplifier, ramp generator, comparator, N-Channel

switch and P-Channel synchronous rectified

switch (which greatly improves efficiency). The

output disconnect feature allows the output to be

completely isolated from the input in shutdown

mode.

The 500KHz switching frequency allows for

smaller

external

components

producing

a

compact solution for a wide range of load

currents. The internal compensation and soft-start

minimizes the external component count and

limits the inrush current during startup. The

MP1543 regulates the output voltage up to 6V

and provides up to 400mA from a 2-cell AA with

a 3.3V output.

The MP1543 is offered in a thin SOT23-5

package.

EVALUATION BOARD REFERENCE

Board Number

Dimensions

EV1543DJ-01A

2.4”X x 2.4”Y x 0.4”Z

FEATURES

• Over 90% Efficiency

• Output to Input Disconnect at Shutdown Mode

• Internal Synchronous Rectifier

• Inrush Current Limiting and Internal Soft-Start

• Internal Compensation

• 1.5A Typical Switch Current Limit

• 500KHz Fixed Switching Frequency

• Zero Current Shutdown Mode

• Thermal Shutdown

• 5-Pin TSOT-23 Package

APPLICATIONS

• MP3 Players

• Handheld Computers and PDAs

• Digital Still and Video Cameras

• External Modems

• Small LCD Displays

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

Power Systems, Inc.

TYPICAL APPLICATION

MP1543

SW

OUT

FB

GND

EN

4

3

1

2

5

1.8V - 3.2V

EN

3.3V

400mA

100

90

80

70

60

50

40

30

1

10

100

1000

LOAD CURRENT (mA)

MP1543-EC01

Efficiency vs

Load Current