LM2931

Series Low Dropout Regulators

General Description

The LM2931 positive voltage regulator features a very low

quiescent current of 1mA or less when supplying 10mA

loads. This unique characteristic and the extremely low

input-output differential required for proper regulation (0.2V

for output currents of 10mA) make the LM2931 the ideal

regulator for standby power systems. Applications include

memory standby circuits, CMOS and other low power pro-

cessor power supplies as well as systems demanding as

much as 100mA of output current.

Designed originally for automotive applications, the LM2931

and all regulated circuitry are protected from reverse battery

installations or 2 battery jumps. During line transients, such

as a load dump (60V) when the input voltage to the regulator

can momentarily exceed the specified maximum operating

voltage, the regulator will automatically shut down to protect

both internal circuits and the load. The LM2931 cannot be

harmed by temporary mirror-image insertion. Familiar regu-

lator features such as short circuit and thermal overload

protection are also provided.

ance for A grade) or an adjustable output with ON/OFF pin.

Both versions are available in a TO-220 power package,

TO-263 surface mount package, and an 8-lead surface

mount package. The fixed output version is also available in

the TO-92 plastic and 6-Bump micro SMD packages.

Features

n

Very low quiescent current

n

Output current in excess of 100 mA

n

Input-output differential less than 0.6V

n

Reverse battery protection

n

60V load dump protection

n

−50V reverse transient protection

n

Short circuit protection

n

Internal thermal overload protection

n

Mirror-image insertion protection

n

Available in TO-220, TO-92, TO-263, SO-8 or 6-Bump

micro SMD packages

n

Available as adjustable with TTL compatible switch

n

See AN-1112 for micro SMD considerations

Connection Diagrams

FIXED VOLTAGE OUTPUT

TO-220 3-Lead Power Package

00525406

Front View

TO-263 Surface-Mount Package

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Top View

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Side View

8-Pin Surface Mount

TO-92 Plastic Package

00525407

Top View

*NC = Not internally connected. Must be electrically isolated from the rest

of the circuit for the micro SMD package.

00525408

Bottom View

March 2002

© 2002 National Semiconductor Corporation

DS005254

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