Product Specification

- 1 -

FEATURES

PC half-bridge (or 494) power supply supervisor +

two 431 + PWM

High integration & few external components

Over-voltage protection for 3.3V, 5V and 12V

Under-voltage protection for 3.3V, 5V and 12V

Under-voltage protection for –12V and/or –5V

Over-power and short-circuit protection

Power-down warning circuitry

Power good circuitry

Delay time for PSON and PG signal

Remote ON/OFF function

On-chip oscillator and error amplifier

Two shunt regulator for 3.3V and 5V-Standby

Latching PWM for cycle-by-cycle switching

Push-pull PWM operation and totem pole outputs

Soft-start and maximum 93% duty cycle

APPLICATIONS

Switching mode power supply for Computers, such

as:

ATX

NLX

SFX (micro-ATX)

DESCRIPTION

STC6105 controller is designed for switching

mode power supply for desktop PCs. It provides all the

functions necessary to monitor and control the output of

the power supply. Remote ON/OFF control, power good

circuitry, some protection features against over-voltage

and over-power are implemented. It directly senses all the

output rails for OVP without the need of external dividers.

An innovated AC-signal sampling circuitry provides a

sufficient power-down warning signal for PG. A built-in

timer generates accuracy timing for control circuit

including the PS-off delay. The cycle-by-cycle PWM

switching prevents the power transformer from the

saturation and ensures the fastest response for the

short-circuit protection which greatly reduce the stress for

power transistors. Two internal precision TL431 shunt

regulators provide stable reference voltage and driver for

3.3V and 5V-standby regulation. Utilizing minimum

number of external components, the STC6105 includes

all of the functions for push-pull and/or half-bridge

topology, decreasing the production cost and PCB space,

and increasing the MTBF for power supply.

MARKING DIAGRAMS

PIN CONFIGURATION

20

1

STC6105

1

2

3

4

5

6

7

8

9

10

20

19

18

17

16

15

14

13

12

11

PSON

V33

V5

OPP

UVAC

NVP

V12

OP2

OP1

PG

FB2

VREF2

VREF1

FB1

GND

COMP

IN

SS

RI

VCC

STC6105

Power Supply Supervisor + Regulator + PWM