MP28373

3A, 28V, 1.4MHz

Step-Down Converter

MP28373 Rev. 1.0

www.MonolithicPower.com

1

12/12/2007

MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.

© 2007 MPS. All Rights Reserved.

The Future of Analog IC Technology

DESCRIPTION

The MP28373 is a 1.4MHz step-down regulator

with a built-in power MOSFET. It achieves 3A

continuous output current over a wide input

supply range with excellent load and line

regulation.

Current mode operation provides fast transient

response and eases loop stabilization.

Fault condition protection includes cycle-by-

cycle current limiting and thermal shutdown.

Adjustable soft-start reduces the stress on the

input source at turn-on. In shutdown mode, the

regulator draws 20μA of supply current.

The MP28373 is available in an 8-pin SOIC

package with an exposed pad, and requires a

minimum number of readily available external

components to complete a 3A step-down DC to

DC converter solution.

EVALUATION BOARD REFERENCE

Board Number

Dimensions

EV28373DN-00A

2.0” x 1.9” x 0.4”

FEATURES

• 3A Continuous Output Current, 4A Peak

Output Current

• Programmable Soft-Start

• 100mΩ Internal Power MOSFET Switch

• Stable with Low ESR Output Ceramic

Capacitors

• Up to 91% Efficiency

• 20μA Shutdown Mode

• Fixed 1.4MHz Frequency

• Thermal Shutdown

• Cycle-by-Cycle Over Current Protection

• Wide 4.75V to 28V Operating Input Range

• Output is Adjustable From 0.92V to 21V

• Under Voltage Lockout

APPLICATIONS

• Distributed Power Systems

• Battery Chargers

• Pre-Regulator for Linear Regulators

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

Monolithic Power Systems, Inc.

TYPICAL APPLICATION

INPUT

OUTPUT

3.3V

3A

MP28373

BS

IN

FB

SW

SS

GND

COMP

EN

1

3

5

6

4

8

7

2

C6

OPEN

OPEN =

AUTOMATIC

STARTUP

C4

C3

R3

C5

C1

CERAMIC

C2

CERAMIC

R2

R1

L1

D1

Efficiency Curve

100

90

80

70

60

0

0.5

1.0

1.5

2.0

2.5

3.0

LOAD CURRENT (A)