4-111

TELCOM SEMICONDUCTOR, INC.

7

6

5

4

3

1

2

8

11

A

VDD

14

B

OSC OUT

4

15

CMPTR

+6V

50

µA

ERROR

AMP

SYNC

3

CT

5

DISCH

7

COMP

9

IN–

1

IN+

2

SOFT

START

8

SHUTDOWN

10

GND

12

RT

6

V+

IN

REFERENCE

REGULATOR

FLIP

FLOP

UNDER

VOLTAGE

OSC

S

R

R

+6V

35C25

PWM

LATCH

16

VREF

13

+4V REF

TC25/35C25-2 10/1/96

FUNCTIONAL BLOCK DIAGRAM

TC25C25

TC35C25

BICMOS PWM CONTROLLERS

GENERAL DESCRIPTION

The TC35C25 family of PWM controllers are CMOS

implementations of the industry standard 3525 voltage

mode SMPS ICs.

These second generation CMOS devices employ

TelCom Semiconductors' Tough BiCMOS

™ process for

latch-up proof operation. They offer much lower power

consumption than any of their previous CMOS or bipolar

counterparts.

These controllers have separate supply pins for the

control and output sections of the circuit. This allows "boot-

strap" operation. The CMOS output stage allows the output

voltage to swing to within 25mV of either rail.

Other improved features include tighter hysteresis and

undervoltage start-up specifications over temperature, and

very low input bias current on all inputs.

FEATURES

s

Low Power BICMOS Construction

s

Low Supply Current at 20 kHz ............... 1.0mA Typ

s

Latch-Up Immunity ................. >500mA on Outputs

s

Below Rail Input Protection .............................. – 5V

s

High Output Drive ................................ 500mA Peak

s

Fast Rise/Fall Time ..................... 50nsec @ 1000pF

s

High Frequency Operation .................. Up to 1MHz

s

Tri-state Sync Pin for Easy Parallel Operation

s

Under Voltage Hysteresis Guaranteed

s

Shutdown Pin Available

s

Double-Ended

s

Soft Start, With Small Cap

s

Low Prop Delay Shutdown to

Output ................................................. 140nsec Typ.

ORDERING INFORMATION

Part No.

Configuration

Pkg./Temperature

TC25C25EOE

Non-Inverting

16-Pin SOIC (Wide)

– 40

°C to +85°C

TC25C25EPE

Non-Inverting 16-Pin Plastic DIP (Narrow)

– 40

°C to +85°C

TC35C25COE

Non-Inverting

16-Pin SOIC (Wide)

0

°C to +70°C

TC35C25CPE

Non-Inverting 16-Pin Plastic DIP (Narrow)

0

°C to +70°C