Innovative Power

TM

- 1 -

www.active-semi.com

Copyright © 2012 Active-Semi, Inc.

ActiveQR

Product Brief, 05-Dec-12

ActiveQR

FEATURES

Technique

Inductance Compensation

voltage, Output Short Protections

CEC Average Efficiency Standards

APPLICATIONS

Cordless Phone, PDAs, E-books

Set-top boxes, DVD players, records

GENERAL DESCRIPTION

The ACT511 is a high performance peak current

and frequency foldback technique to reduce EMI

and

improve

efficiency.

ACT511’s

maximum

switching frequency is set at 90kHz. Very low

standby power, good dynamic response and

accurate voltage regulation is achieved with an

opto-coupler and the secondary side control circuit.

The burst mode operation enables low standby

power of 100mW with small output voltage ripple.

technology, ACT511 increases the average system

efficiency compared to conventional solutions and

exceeds the latest ES2.0 efficiency standard with

good margin.

ACT511 integrates comprehensive protection. In

case of over temperature, over voltage, short

winding, short current sense resistor, open loop an

d overload conditions, it would enter into auto

restart mode including Cycle-by-Cycle current

limiting.

ACT511 is to achieve no overshoot and very short

rise time even with big capacitive load (4000µF)

with the built-in fast and soft start process.

The Quasi-Resonant (QR) operation mode can

effectively improve efficiency, reduce the EMI noise

and further reduce the components in input filter.

ACT511 is for application up to 60 Watt.

Figure 1:

Simplified Application Circuit

ACT511