MC34025

MC33025

DW SUFFIX

PLASTIC PACKAGE

CASE 751G

(SO–16L)

P SUFFIX

PLASTIC PACKAGE

CASE 648

PIN CONNECTIONS

16

1

16

1

11

5

2

1

Error Amp

Noninverting Input

Current Limit/

Shutdown

Ground

Output A

Power Ground

VC

Output B

VCC

Vref

9

10

12

13

14

15

16

8

7

6

4

3

(Top View)

Soft–Start

Ramp

CT

RT

Clock

Error Amp Output

Error Amp

Inverting Input

Device

Operating

Temperature Range

Package

ORDERING INFORMATION

MC33025DW

MC34025P

TA = 0° to +70°C

SO–16L

Plastic DIP

TA = – 40° to +105°C

MC33025P

Plastic DIP

MC34025DW

SO–16L

Order this document by MC34025/D

1

MOTOROLA ANALOG IC DEVICE DATA

High Speed Double-Ended

PWM Controller

The MC34025 series are high speed, fixed frequency, double–ended

pulse width modulator controllers optimized for high frequency operation.

They are specifically designed for Off–Line and DC–to–DC converter

applications offering the designer a cost effective solution with minimal

external components. These integrated circuits feature an oscillator, a

temperature compensated reference, a wide bandwidth error amplifier, a

high speed current sensing comparator, steering flip–flop, and dual high

current totem pole outputs ideally suited for driving power MOSFETs.

Also included are protective features consisting of input and reference

undervoltage lockouts each with hysteresis, cycle–by–cycle current limiting,

and a latch for single pulse metering.

The flexibility of this series allows it to be easily configured for either

current mode or voltage mode control.

Simplified Application

Error

Amp

Oscillator

4

16

Vref

Clock

5

6

RT

CT

3

7

Ramp

Error Amp

Output

2

Inverting

Input 1

8

Soft–Start

Soft–Star

t

Latching

PWM and

Steering

Flip Flop

Ground

10

9

Current

Limit/

Shutdown

Output B

14

VC

13

VCC

15

UVLO

5.1V

Reference

11

Noninverting

Input

Power

Ground

12

Output A

This device contains 227 active transistors.

© Motorola, Inc. 1996

Rev 1