LM79XX Series 3-Terminal Negative Regulators
November 1994
LM79XX Series 3-Terminal Negative Regulators
General Description
The LM79XX series of 3-terminal regulators is available with
fixed output voltages of
b
5V
b
8V
b
12V and
b
15V
These devices need only one external component a com-
pensation capacitor at the output The LM79XX series is
packaged in the TO-220 power package and is capable of
supplying 1 5A 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
Y
Y
Y
Thermal short circuit and safe area protection
High ripple rejection
1 5A output current
4% tolerance on preset output voltage
Connection Diagrams
TO-220 Package
Typical Applications
Fixed Regulator
TL H 7340 – 3
TL H 7340 – 14
Front View
Order Number LM7905CT LM7912CT or LM7915CT
See NS Package Number TO3B
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
C
1995 National Semiconductor Corporation
TL H 7340
RRD-B30M115 Printed in U S A