©2000 Fairchild Semiconductor International

www.fairchildsemi.com

Rev. .5.0

Features

• Precision fixed operating frequency

• 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

Description

The SPS product family is specially designed for an off-line

SMPS with minimal external components. The SPS consist of

high voltage power SenseFET and current mode PWM control-

ler 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 volt-

age protection, temperature compensated precision current

sources for loop compensation and fault protection circuit.

Compared to discrete MOSFET and controller or RCC switch-

ing converter solution, a SPS 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

KA1L0380B/KA1L0380RB/KA1M0380RB/

KA1H0380RB

Fairchild Power Switch(SPS)