©2003 Fairchild Semiconductor Corporation

www.fairchildsemi.com

Rev.1.0.3

Features

• Precision Fixed Operating Frequency (70kHz)

• Low Start-up Current(Typ. 100uA)

• Pulse by Pulse Current Limiting

• Over Load Protection

• Over Current Protection

• Over Voltage Protection (Min. 25V)

• Internal Thermal Shutdown Function

• Under Voltage Lockout

• Internal High Voltage Sense FET

• Latch 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

frequency oscillator, under voltage lock-out, leading edge

blanking, optimized gate turn-on/turn-off driver, thermal

shutdown protection, over voltage protection, and

temperature compensated precision current sources for

loop compensation and fault protection circuitry. compared

Fairchild Power Switch(FPS) can reduce total component

count, design size, weight and at the same time increase

efficiency, productivity, and system reliability. It has a basic

platform well suited for cost effective design in either a

flyback converter or a forward converter.

TO-3P-5L

1. DRAIN 2. GND 3. VCC 4. FB 5. S/S

1

Internal Block Diagram

Sense

FET

15V/9V

UVLO

Vref

2.5R

5uA

R

1mA

Good Logic

INTERNAL

BIAS

LEB

+

++

+

-

S

R

Q

OSC

CLK

7.5V

Shutdown

Latch

Power-on Reset

/Auto-restart

Rsense

※

LEB : Leading Edge Blanking

※

OCL : Over Current Limit

Vcc

GND

Drain

+

++

+

-

14V

27V

+

++

+

-

OVP-out

OVP

S

R

Q

3

2

1

VOLTAGE

LIMIT

CIRCUIT

OLP

OCL

TSD

OVP-out

5V

Soft Start 5

Feedback 4

KA5M0965Q

Fairchild Power Switch(FPS)