©2003 Fairchild Semiconductor Corporation

www.fairchildsemi.com

Rev.1.0.2

Features

• Precision Fixed Operating Frequency

• KA1M0265R (70kHz) , KA1H0265R (100kHz)

• Pulse by Pulse Over Current Limiting

• Over Load Protection

• Over Voltage Protection (Min. 23V)

• Internal Thermal Shutdown Function

• Under Voltage Lockout

• Internal High Voltage Sense FET

•Auto Restart

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

controller IC. 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, temperature compensated

precision current sources for loop compensation and fault

protection circuit. compared to discrete MOSFET and

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-220F-4L

1

Internal Block Diagram

32V

5

µA

9V

2.5R

1R

1mA

0.1V

+

−

OVER VOLTAGE S/D

+

−

7.5V

25V

Thermal S/D

S

R

Q

Power on reset

+

−

L.E.B

S

R

Q

OSC

5V

Vref

Internal

bias

Good

logic

SFET

#2 DRAIN

#1 GND

#4 FB

KA1M0265R/KA1H0265R

Fairchild Power Switch(FPS)