Description

These voltage regulators are intended as complements

to the popular MC78xx Series devices. These negative reg-

ulators are available in the same seven-voltage options as

the MC78xx devices. In addition, one extra voltage

option commonly employed in MECL systems is also

available in the negative MC79xx Series.

Available in fixed output voltage options from –5.0 to –24

volts, these regulators employ current limiting, thermal shut-

down, and safe-area compensation – making them remark-

ably rugged under most operating conditions. With adequate

heatsinking they can deliver output currents in excess of

1.5 ampere.

Features

• Output current in excess of 1.5 Ampere

• No external components required

• Internal thermal overload protection

• Internal short-circuit current limiting

• Output transistor safe-area compensation

• Output voltage offered in 2% tolerance

Mechanical Data

Case: TO-220 Package

Weight: approx. 2.24g

Case outline is on the back page

Pin Arrangement

Input

Output

R1

R2

GND

Reference

Voltage

Short Circuit

Protection

+

--

Q1

Q2

I1

I2

Internal Block Diagram

Output

Input

Cin

0.33

µF

MC79xx

Co

0.1

µF

1. Ground

2. Input

3. Output

(heatsink connected to pin 2)

Standard Application

Notes:

A common ground is required between the input and the output voltages.

The input voltage must remain typically 2.0V more negative even during

the high point on the input ripple voltage.

xx = these two digits of the part number indicate output voltage.

Cin is required if regulator is located an appreciable distance from power

supply filter.

Co improves stability and transient response.

1

2

3

TO-220

New Product

3-Terminal Fixed Negative Voltage Regulators

MC79xxCT Series

Vishay

formerly General Semiconductor

Document Number 74814

www.vishay.com

11-Jun-02

1