February 2005

1

MIC3975

MIC3975

Micrel

Ordering Information

Part Number

Standard

Pb-Free

Voltage Junction Temp. Range

Package

MIC3975-1.65BMM

MIC3975-1.65YMM

1.65V

–40°C to +125°C

MSOP-8

MIC3975-1.8BMM

MIC3975-1.8YMM

1.8V

–40°C to +125°C

MSOP-8

MIC3975-2.5BMM

MIC3975-2.5YMM

2.5V

–40°C to +125°C

MSOP-8

MIC3975-3.0BMM

MIC3975-3.0YMM

3.0V

–40°C to +125°C

MSOP-8

MIC3975-3.3BMM

MIC3975-3.3YMM

3.3V

–40°C to +125°C

MSOP-8

MIC3975-5.0BMM

MIC3975-5.0YMM

5.0V

–40°C to +125°C

MSOP-8

MIC3975BMM

MIC3975YMM

Adj.

–40°C to +125°C

MSOP-8

MIC3975

750mA µCap Low-Voltage Low-Dropout Regulator

General Description

The MIC3975 is a 750mA low-dropout linear voltage regula-

tors that provide low-voltage, high-current output from an

extremely small package. Utilizing Micrel’s proprietary Super

β

eta PNP™ pass element, the MIC3975 offers extremely low

dropout (typically 300mV at 750mA) and low ground current

(typically 6.5mA at 750mA).

The MIC3975 is ideal for PC add-in cards that need to con-

vert from standard 5V to 3.3V or 3.0V, 3.3V to 2.5V or 2.5V

to 1.8V or 1.65V. A guaranteed maximum dropout voltage

of 500mV over all operating conditions allows the MIC3975

to provide 2.5V from a supply as low as 3.0V and 1.8V or

1.65V from a supply as low as 2.25V.

The MIC3975 is fully protected with overcurrent limiting,

thermal shutdown, and reversed-battery protection. Fixed

voltages of 5.0V, 3.3V, 3.0, 2.5V, 1.8V, and 1.65V are avail-

able. An adjustable output voltage option is available for

voltages down to 1.24V.

For other voltages, contact Micrel.

Typical Applications

Features

• Fixed and adjustable output voltages to 1.24V

• 300mV typical dropout at 750mA

Ideal for 3.0V to 2.5V conversion

Ideal for 2.5V to 1.8V or 1.65V conversion

• Stable with ceramic capacitor

• 750mA minimum guaranteed output current

• 1% initial accuracy

• Low ground current

• Current limiting and thermal shutdown

• Reversed-battery protection

• Reversed-leakage protection

• Fast transient response

• Low-profile MSOP-8

Applications

• Fiber optic modules

• LDO linear regulator for PC add-in cards

• PowerPC™ power supplies

• High-efficiency linear power supplies

• SMPS post regulator

• Multimedia and PC processor supplies

• Battery chargers

• Low-voltage microcontrollers and digital logic

Super βeta PNP is a trademark of Micrel, Inc.

Micrel, Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com

IN

R1

100k

2.5V

Error

Flag

Output

3.3V

10F

ceramic

EN

OUT

FLG

GND

MIC3975-2.5BMM

ENABLE

SHUTDOWN

2.5V/750mA Regulator with Error Flag

IN

R1

1.5V

2.5V

10F

ceramic

R2

EN

OUT

ADJ

GND

MIC3975BMM

ENABLE

SHUTDOWN

1.5V/750mA Adjustable Regulator