LM78XX Series Voltage Regulators
February 1995
LM78XX Series Voltage Regulators
General Description
The LM78XX series of three terminal regulators is available
with several fixed output voltages making them useful in a
wide range of applications One of these is local on card
regulation eliminating the distribution problems associated
with single point regulation The voltages available allow
these regulators to be used in logic systems instrumenta-
tion HiFi and other solid state electronic equipment Al-
though designed primarily as fixed voltage regulators these
devices can be used with external components to obtain
adjustable voltages and currents
The LM78XX series is available in an aluminum TO-3 pack-
age which will allow over 1 0A load current if adequate heat
sinking is provided Current limiting is included to limit the
peak output current to a safe value Safe area protection for
the output transistor is provided to limit internal power dissi-
pation If internal power dissipation becomes too high for
the heat sinking provided the thermal shutdown circuit
takes over preventing the IC from overheating
Considerable effort was expanded to make the LM78XX se-
ries of regulators easy to use and mininize the number
of external components It is not necessary to bypass the
output although this does improve transient response Input
bypassing is needed only if the regulator is located far from
the filter capacitor of the power supply
For output voltage other than 5V 12V and 15V the LM117
series provides an output voltage range from 1 2V to 57V
Features
Y
Y
Y
Y
Y
Y
Output current in excess of 1A
Internal thermal overload protection
No external components required
Output transistor safe area protection
Internal short circuit current limit
Available in the aluminum TO-3 package
Voltage Range
LM7805C
LM7812C
LM7815C
5V
12V
15V
Schematic and Connection Diagrams
Metal Can Package
TO-3 (K)
Aluminum
TL H 7746 – 2
Bottom View
Order Number LM7805CK
LM7812CK or LM7815CK
See NS Package Number KC02A
Plastic Package
TO-220 (T)
TL H 7746 – 3
Top View
Order Number LM7805CT
LM7812CT or LM7815CT
See NS Package Number T03B
TL H 7746 – 1
C
1995 National Semiconductor Corporation
TL H 7746
RRD-B30M115 Printed in U S A
NSC [ NATIONAL SEMICONDUCTOR ]
