MIC2940A/2941A
1.2A Low-Dropout Voltage Regulator
General Description
The MIC2940A and MIC2941A are “bulletproof” efficient
voltage regulators with very low dropout voltage (typically
40mV at light loads and 350mV at 1A), and low quiescent
current (240µA typical). The quiescent current of the
MIC2940A increases only slightly in dropout, thus
prolonging battery life. Key MIC2940A features include
protection against reversed battery, fold-back current
limiting, and automotive “load dump” protection (60V
positive transient).
The MIC2940 is available in both
fixed
voltage (3.3V, 5V,
and 12V) and adjustable voltage configurations. The
MIC2940A-xx devices are three pin,
fixed
voltage
regulators. A logic-compatible shutdown input is provided
on the adjustable MIC2941A, which enables the regulator
to be switched on and off.
Data sheets and support documentation can be found on
Micrel’s web site at: www.micrel.com.
Features
•
•
•
•
•
•
•
•
High output voltage accuracy
Guaranteed 1.25A 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
positive transients
•
Logic-controlled electronic shutdown
•
Output programmable from 1.24V to 26V(MIC2941A)
•
Available in TO-220, TO-263, TO-220-5, and TO-263-5
packages.
Applications
•
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
•
Voltage reference
•
High efficiency linear power supplies
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Pin Configuration
1
2
3
1
2 3
4
5
TO-263-3
(MIC2940A-xxBU/WU)
1
2
3
TO-263-5
(MIC2941ABU/WU)
MIC2941A Pinout
1) Adjust
2) Shutdown
3) Ground
4) Input
5) Output
1 2 3 4
5
TO-220-3
(MIC2940A-xxBT/WT)
MIC2940A Pinout
1) Input
2) Ground
3) Output
TO-220-5
(MIC2941ABT/WT)
The TAB is Ground on 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
July 2007
M9999-071307