Innovative Power

TM

- 1 -

www.active-semi.com

Copyright © 2013 Active-Semi, Inc.

FEATURES

Radiation Regulation without adding EMI

Components

Current Control

Efficiency, Lowers Cost, and Reduces

Component Count

APPLICATIONS

GENERAL DESCRIPTION

ACT4533 is a wide input voltage, high efficiency

Active CC step-down DC/DC converter that

operates in either CV (Constant Output Voltage)

mode or CC (Constant Output Current) mode.

ACT4533 provides up to 3A output current at

125kHz switching frequency.

Active CC is a patent-pending control scheme to

achieve highest accuracy sensorless constant

current control. Active CC eliminates the expensive,

high accuracy current sense resistor, making it ideal

for battery charging applications and adaptors with

accurate current limit. The ACT4533 achieves

higher efficiency than traditional constant current

switching regulators by eliminating its associated

power loss.

Protection features include cycle-by-cycle current

limit, thermal shutdown, and frequency foldback at

short circuit. The devices are available in a SOP-

8EP package and require very few external devices

for operation.

ACT4533

Wide-Input Sensorless CC/CV Step-Down DC/DC Converter

Output Current (mA)

0

400

800

1200

1600

2000

2400

2800

6.0

5.0

4.0

3.0

2.0

1.0

0.0

CC/CV Curve

Rev 1, 25-Feb-13