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www.active-semi.com

Copyright © 2014 Active-Semi, Inc.

Active-Semi Proprietary―For Authorized Recipients and Customers

ActiveQR

Rev 4, 13-Feb-14

ActiveQR

FEATURES

Technique

voltage, Output Short Protections

CEC Average Efficiency Standards

APPLICATIONS

Cordless Phone, PDAs, E-books

Set-top boxes, DVD players, records

GENERAL DESCRIPTION

The ACT512 is a high performance peak current

and frequency foldback technique to reduce EMI

and improve efficiency. ACT512’s maximum design

switching frequency is set at 75kHz. Very low

standby power, good dynamic response and

accurate voltage regulation is achieved with an

opto-coupler and the secondary side control circuit.

The idle mode operation enables low standby

power of 100mW with small output voltage ripple.

technology, ACT512 increases the average system

efficiency compared to conventional solutions and

exceeds the latest ES2.0 efficiency standard with

good margin.

ACT512 integrates comprehensive protection. In

case of over temperature, over voltage, winding

short, current sense resistor short, open loop and

overload conditions, it would enter into auto restart

mode including Cycle-by-Cycle current limiting.

ACT512 is to achieve no overshoot and very short

rise time even with a big capacitive load with the

built-in fast and soft start process.

In full load condition, ACT512 is able to be

designed to work in both CCM mode and DCM

mode to meet different types of applications. Quasi-

Resonant (QR) operation mode can improve

efficiency during DCM operation, and reduce EMI

and further reduce the components in input filter.

ACT512 is ideal for applications up to 60 Watts.

Figure 1:

Simplified Application Circuit

ACT512