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Copyright © 2015 Active-Semi, Inc.

ACT4528

40V/3.0A CV/CC Buck Converter Featuring QC2.0 and USB Auto-Detect

2.65A

5.1V

Vout

Iout

3.2V

9.1V

12.1V

FEATURES

Devices

Protection for 5.1V/9.1V/12.1V Outputs

APPLICATIONS

GENERAL DESCRIPTION

ACT4528 is a wide input voltage, high efficiency

step-down DC/DC converter that operates in either

CV (Constant Output Voltage) mode or CC

(Constant Output Current) mode. ACT4528 has

QC2.0 decoding built in to provide 5.1V/9.1V/12.1V

outputs as requested by attached portable devices.

It also supports Apple 2.4A, Samsung and BC1.2

devices to charge at full current rate.

ACT4528 has accurate output current limits under

constant

current

regulation

to

meet

MFi

specification. It can provide up to 3.0A output

current at 125kHz switching frequency. ACT4528

utilizes adaptive drive technique to achieve good

EMI performance while main >90% efficiency at full

load for mini size CLA designs. ACT4528 also has

output short circuit protection with hiccup mode.

The average output current is reduced to below

6mA when output is shorted to ground. Other

features include output over voltage protection and

thermal shutdown.

ACT4528 is available in a SOP-8EP package and

require very few external components for operation.

Typical Application Circuit

V/I Profile

ACT4528

HSB

IN

SW

4.5V to 40V

DM

Rcs

25mΩ

CSP

DP

Vout

GND

D-

D+

GND

CSN

5V/9V/12V

C2

10μF

C3

22nF

C5

220μF

C1

47μF

C4

22μF

C6

2.2μF

D1

SK54L

L1

47μH