- 1 -

www.active-semi.com

Copyright © 2008 Active-Semi, Inc.

TYPICAL APPLICATION CIRCUIT

ACT4088

Rev0, 13-May-08

28V, 1.5A, 1.4MHz Step-Down DC/DC Converter in SOT23-6

FEATURES

APPLICATIONS

GENERAL DESCRIPTION

The ACT4088 is a current-mode step-down DC/DC

converter that supplies up to 1.5A into 5V from a

12V input. 1.4MHz switching frequency allows the

use of tiny external components, and internal loop

compensation provides simple, stable power sup-

plies with a minimum of external components. Opti-

mized for use with ceramic input and output capaci-

tors, the ACT4088 provides a very compact 1.5A

power supply for space constrained mobile and

consumer applications.

The ACT4088 operates over a wide input voltage

range and utilizes current-mode operation to pro-

vide excellent line and load transient response

while requiring no external compensation compo-

nents. Fault protection includes cycle-by-cycle cur-

rent limiting, frequency fold-back, hiccup mode, and

thermal shutdown. Internal soft-start provides a

controlled startup with no overshoot, even at light

loads.

The ACT4088 is available in a tiny SOT23-6 pack-

age and requires very few external components.

ACT4088

IN

EN

BST

SW

FB

G

4.5V to 28V

OFF

ON