©2002 Fairchild Semiconductor Corporation

www.fairchildsemi.com

Rev. 1.0.1

Features

•5V

±1% Reference

• Oscillator Sync Terminal

• Internal Soft Start

• Deadtime Control

• Under Voltage Lockout

Description

The KA3525A is a monolithic integrated circuit that

includes all of the control circuits necessary for a pulse width

modulating regulator. There are a voltage reference, an error

amplifier, a pulse width modulator, an oscillator, an under

voltage lockout, a soft start circuit, and the output driver in

the chip.

16-DIP

1

Internal Block Diagram

16

15

12

1

2

9

8

10

5

7

3

6

4

14

11

13

U.V.L.O.

BAND GAP

REF 5V

LATCH

S

R

F/F

Q

Q

5K

VC

OUTPUT A

OUTPUT B

OSCILLATOR

DISCHARGE

5K

ERR

AMP

PWM

COMP

_

+

_

+

GND

EA(-)

EA(+)

EAOUT

C

(SOFT

START)

SHUT DOWN

SYNC

OSC

OUTPUT

KA3525A

SMPS Controller