©2003 Fairchild Semiconductor Corporation

www.fairchildsemi.com

Rev.1.0.3

Features

• Adjustable Switching Frequency

• Intelligent Power Saving Mode

• Pulse by Pulse Current Limiting

• Over Current Latch Protection

• Over Voltage Protection

• Internal Thermal Shutdown Function

• Built-in Soft Start Function

• Internal High Voltage Sense FET

• Auto-Restart Mode

Description

The Fairchild Power Switch(FPS) product family is specially

designed for an off-line SMPS with minimal external

components. The Fairchild Power Switch(FPS) consist of

high voltage power SenseFET and current mode PWM IC.

Included PWM controller features integrated fixed

oscillator, under voltage lock out, leading edge blanking,

optimized gate turn-on/turn-off driver, thermal shut down

protection, over voltage protection, and temperature

compensated precision current sources for loop

compensation and fault protection circuitry. compared to dis-

converter solution, a Fairchild Power Switch(FPS) can

reduce total component count, design size, and weight and at

the same time increase efficiency, productivity, and system

reliability.It has a basic platform well suited for cost

effective design in PC SMPS with Power Saving function.

TO-220-5L

1

Internal Block Diagram

GND

Vcc

Drain

Feedback

SenseFET

UVLO

Vref

R

BIAS

OSC

CLK

Shutdown Latch

POWER-ON

RESET

Rsense

S

R

Q

4

3

2

1

15V/9V

2.5V

GOOD LOGIC

VG

LIMIT

CIRCUIT

VG

Vs

5

Ct

SOFT-START

(5mS)/( 0 ~ 5V )

LEB

PS MODE

2.5R

0.5V

TSD

(Tj=170 ℃)

S

R

Q

OLP

(Vfb=7V)

OVP

(Vcc=27V)

AUTO

RESTART

S

R

Q

OCL

(Vs=1.1V)

2V

S

R

Q

1mS

VCC

VZ

VREF

VCC

5uA

900uA

0.7V

0.4V/0.6V

5uA

OUTPUT OFF

OUTPUT OFF

KA5P0680C

Fairchild Power Switch(FPS)