CM6901

SLS (SRC/LLC+SR) Controller with 1 FM+2 PWMs

2009/11/02 Rev1.4

Champion Microelectronic Corporation

Page 10

V T o I

2.5 V

VF B

R SET

OS C

Vre f

RT

CT

+

-

2 PWMings:

SR Ideal Diode PWMing (Synchronous Outputs)

SR Ideal Diode PWMing for synchronous drivers is accomplished by comparing the voltage signal at the RSET pin

to RTCT ramp. The pulse-width reduction happens when the voltage at the RSET is lower than 1.5V. This allows

safe operation of the power converter with synchronous rectification when the switching frequency is below the

highest resonant point frequency fr1.

V To I

2.5V

VFB

OSC

Vref

RT

CT

+

-

Rf1

Rf3

Vout

RSET

FEAO

Rf4

+

-

To

Logic

1.5V

1.25V

3V

SRDRV

PR IDRV

D ecreasing Pulsewidth

with V(RSET)<1.5V