TLH7340

November 1994

LM79XX Series 3-Terminal Negative Regulators

General Description

The LM79XX series of 3-terminal regulators is available with

These devices need only one external componenta com-

pensation capacitor at the output The LM79XX series is

packaged in the TO-220 power package and is capable of

supplying 15A of output current

These regulators employ internal current limiting safe area

protection and thermal shutdown for protection against vir-

tually all overload conditions

Low ground pin current of the LM79XX series allows output

voltage to be easily boosted above the preset value with a

resistor divider

The low quiescent current drain of

these devices with a specified maximum change with line

and load ensures good regulation in the voltage boosted

mode

For applications requiring other voltages see LM137 data

sheet

Features

Y

Thermal short circuit and safe area protection

Y

High ripple rejection

Y

15A output current

Y

4% tolerance on preset output voltage

Connection Diagrams

TO-220 Package

TLH7340 – 14

Front View

Order Number LM7905CT LM7912CT or LM7915CT

See NS Package Number TO3B

Typical Applications

Fixed Regulator

TLH7340 – 3

Required if regulator is separated from filter capacitor by

more than 3

For value given capacitor must be solid

tantalum 25 mF aluminum electrolytic may be substituted

Required for stability For value given capacitor must be

solid tantalum 25 mF aluminum electrolytic may be substi-

tuted Values given may be increased without limit

For output capacitance in excess of 100 mF a high current

diode from input to output (1N4001 etc) will protect the

regulator from momentary input shorts

C1995 National Semiconductor Corporation

RRD-B30M115Printed in U S A