©2000 Fairchild Semiconductor International

www.fairchildsemi.com

Rev. .5.0

Features

• Precision fixed operating frequency (100/67/50kHz)

• Low start-up current(typ. 100uA)

• Pulse by pulse current limiting

• Over current protection

• Over voltage protecton (Min. 25V)

• Internal thermal shutdown function

• Under voltage lockout

• Internal high voltage sense FET

• Auto-restart mode

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

IC. Included PWM controller features integrated fixed fre-

quency oscillator, under voltage lock-out, leading edge

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

shutdown protection, over voltage protection, and tempera-

ture compensated precision current sources for loopcompen-

sation and fault protection circuitry. Compared to discrete

MOSFET and PWM controller or RCC solution, a SPS can

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

same time increase efficiency, productivity, and system reli-

ability. It has a basic platform well suited for cost-effective

design in either a flyback converter or a forward converter.

TO-220F-4L

Internal Block Diagram

Vcc

Vcc

Vcc

Vcc

FB

FB

FB

FB

DRAIN

GND

GND

GND

GND

SFET

SFET

SFET

SFET

5V

Vref

OSC

INTERNAL

BIAS

GOOD

LOGIC

Q

S

R

_

+

2.5R

1R

9V

1 mA

5 uA

+

_

7.5V

THERMAL S/D

Q

S

R

POWER ON RESET

L.E.B

+

_

27V

UVLO

Rsens

KA5H0380R/KA5M0380R/KA5L0380R

SPS