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