MIC2937A/29371/29372
Micrel, Inc.
MIC2937A/29371/29372
750mA Low-Dropout Voltage Regulator
General Description
Features
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High output voltage accuracy
The MIC2937Afamily are “bulletproof” efficient voltage regu-
lators with very low dropout voltage (typically 40mV at light
loads and 300mV at 500mA), and very low quiescent current
(160µA typical). The quiescent current of the MIC2937A in-
creases only slightly in dropout, thus prolonging battery life.
Key MIC2937A features include protection against reversed
battery,fold-backcurrentlimiting,andautomotive“loaddump”
protection (60V positive transient).
Guaranteed 750mA output
Low quiescent current
Low dropout voltage
Extremely tight load and line regulation
Very low temperature coefficient
Current and thermal limiting
Input can withstand –20V reverse battery and +60V posi-
tive transients
The MIC2937 is available in several configurations. The
MIC2937A-xx devices are three pin fixed voltage regulators
with 3.3V, 5V, and 12V outputs available. The MIC29371 is
a fixed regulator offering logic compatible ON/OFF switching
input and an error flag output. This flag may also be used as
a power-on reset signal. A logic-compatible shutdown input
is provided on the adjustable MIC29372, which enables the
regulator to be switched on and off.
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Error flag warns of output dropout
Logic-controlled electronic shutdown
Output programmable from 1.24V to 26V(MIC29372)
Available in TO-220, TO-263, TO-220-5, and TO-263-5
packages.
Applications
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Battery Powered Equipment
Cellular Telephones
Laptop, Notebook, and Palmtop Computers
PCMCIA VCC and VPP Regulation/Switching
Bar Code Scanners
Automotive Electronics
SMPS Post-Regulator/ DC to DC Modules
High Efficiency Linear Power Supplies
Pin Configuration
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2 3 4 5
1 2 3
INPUT GROUND OUTPUT
TO-263-5 Package
TO-263 Package
(MIC29371/29372BU/WU)
(MIC2937A-xxBU/WU)
Five Lead Package Pin Functions:
MIC29371 MIC29372
1
2 3 4 5
1 2 3
1) Error
Adjust
INPUT GROUND OUTPUT
2) Input
3) Ground
4) Output
Shutdown
Ground
Input
TO-220 Package
(MIC2937A-xxBT/WT)
TO-220-5 Package
(MIC29371/29372BT/WT)
5) Shutdown Output
The TAB is Ground on the TO-220 and TO-263 packages.
Micrel, Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
May 2006
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MIC2937A/29371/29372