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 processor 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 regulator features such as short circuit and thermal overload protection are also provided.
The LM2931 family includes a fixed 5V output (±3.8% tolerance 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 package.
Features
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Very low quiescent current
Output current in excess of 100 mA
Input-output differential less than 0.6V
Reverse battery protection
60V load dump protection
−50V reverse transient protection
Short circuit protection
Internal thermal overload protection
Mirror-image insertion protection
Available in TO-220, TO-92, TO-263, or SO-8 packages
Available as adjustable with TTL compatible switch
Connection Diagrams
FIXED VOLTAGE OUTPUT
TO-220 3-Lead Power Package
TO-263 Surface-Mount Package
525406
Front View
525411
Top View
525412
Side View
8-Pin Surface Mount
TO-92 Plastic Package
525408
Bottom View
525407
*NC = Not internally connected. Must be electrically isolated from the rest of
the circuit for the micro SMD package.
Top View
© 2011 National Semiconductor Corporation
5254
www.national.com
LM2931 Series Low Dropout Regulators
April 14, 2011
