February 2003

1

MIC3975

MIC3975

Micrel

Ordering Information

Part Number

Voltage

Junction Temp. Range

Package

MIC3975-1.65BMM

1.65V

–40

°C to +125°C

MSOP-8

MIC3975-1.8BMM

1.8V

–40

°C to +125°C

MSOP-8

MIC3975-2.5BMM

2.5V

–40

°C to +125°C

MSOP-8

MIC3975-3.0BMM

3.0V

–40

°C to +125°C

MSOP-8

MIC3975-3.3BMM

3.3V

–40

°C to +125°C

MSOP-8

MIC3975-5.0BMM

5.0V

–40

°C to +125°C

MSOP-8

MIC3975BMM

Adj.

–40

°C to +125°C

MSOP-8

MIC3975

750mA

Final Information

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

βeta 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 convert

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

available. 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. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 944-0970 • http://www.micrel.com

IN

R1

100k

2.5V

Error

Flag

Output

3.3V

10

µF

ceramic

EN

OUT

FLG

GND

MIC3975-2.5BMM

ENABLE

SHUTDOWN

2.5V/750mA Regulator with Error Flag

IN

R1

1.5V

2.5V

10

µF

ceramic

R2

EN

OUT

ADJ

GND

MIC3975BMM

ENABLE

SHUTDOWN

1.5V/750mA Adjustable Regulator