©2002 Fairchild Semiconductor Corporation

www.fairchildsemi.com

Rev. 1.0.1

Features

• Low Start Current 0.2mA (Typ)

• Operating Range Up To 500kHz

• Cycle by Cycle Current Limiting

• Under Voltage Lock Out With Hysteresis

• Short Shutdown Delay Time: Typ.100ns

• High Current Totem-Pole Output

• Output Swing Limiting: 22V

Description

The KA3882C/KA3883C is a fixed PWM controller for Off

Line and DC to DC converter applications. The internal

circuits include an UVLO, a low start up current circuit, a

temperature compensated reference, a high gain error

amplifier, a current sensing comparator, and the high current

totem-pole output for driving a POWER MOSFET. Also the

KA3882C/KA3883C provides low start-up current below

0.3mA and short shutdown delay time typ. 100ns. The

KA3882C has the UVLO threshold of 16V (on) and

10V(off). The KA3883C is 8.4V(on) and 7.6V(off). The

KA3882C and KA3883C can operate within 100% duty

cycle.

8-DIP

8-SOP

1

1

Internal Block Diagram

8

+

-

7

5

SET/

RESET

5V

Internal

Bias

Good LOGIC

2

R

S

OSCILLATOR

1

3

4

T

7

6

5

UVLO

29V

22V

1/3

Error Amp

1V

C.S

Comp.

PWM

LATCH

COMP

C.S

OUTPUT

GND

PWR

PWR

GND

KA3882C/KA3883C

SMPS Controller