MIC2940A/2941A

1.2A Low-Dropout Voltage Regulator

Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (

July 2007

M9999-071307

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

12

3

12 3 4 5

12

3

TO-263-3

(MIC2940A-xxBU/WU)

MIC2940A Pinout

1) Input

2) Ground

3) Output

12 3

4 5

TO-263-5

(MIC2941ABU/WU)

MIC2941A Pinout

1) Adjust

2) Shutdown

3) Ground

4) Input

5) Output

TO-220-3

(MIC2940A-xxBT/WT)

The TAB is Ground on TO-220 and TO-263 packages

TO-220-5

(MIC2941ABT/WT)