June 2000

1

MIC39100/39101/39102

MIC39100/39101/39102

Micrel

Ordering Information

Part Number

Voltage

Junction Temp. Range

Package

MIC39100-1.8BS

1.8V

–40

°C to +125°C

SOT-223

MIC39100-2.5BS

2.5V

–40

°C to +125°C

SOT-223

MIC39100-3.3BS

3.3V

–40

°C to +125°C

SOT-223

MIC39100-5.0BS

5.0V

–40

°C to +125°C

SOT-223

MIC39101-1.8BM

1.8V

–40

°C to +125°C

SOP-8

MIC39101-2.5BM

2.5V

–40

°C to +125°C

SOP-8

MIC39101-3.3BM

3.3V

–40

°C to +125°C

SOP-8

MIC39101-5.0BM

5.0V

–40

°C to +125°C

SOP-8

MIC39102BM

Adj.

–40

°C to +125°C

SOP-8

MIC39100/39101/39102

1A Low-Voltage Low-Dropout Regulator

General Description

The MIC39100, MIC39101, and MIC39102 are 1A low-

dropout linear voltage regulators that provide low-voltage,

high-current output from an extremely small package. Utiliz-

ing Micrel’s proprietary Super

βeta PNP™ pass element, the

MIC39100/1/2 offers extremely low dropout (typically 410mV

at 1A) and low ground current (typically 11mA at 1A).

The MIC39100 is a fixed output regulator offered in the

SOT-223 package. The MIC39101 and MIC39102 are fixed

and adjustable regulators, respectively, in a thermally en-

hanced power 8-lead SOP (small outline package).

The MIC39100/1/2 is ideal for PC add-in cards that need to

convert from standard 5V to 3.3V, 3.3V to 2.5V or 2.5V to

1.8V. A guaranteed maximum dropout voltage of 630mV over

all operating conditions allows the MIC39100/1/2 to provide

2.5V from a supply as low as 3.13V and 1.8V from a supply

as low as 2.43V.

The MIC39100/1/2 is fully protected with overcurrent limiting,

thermal shutdown, and reversed-battery protection. Fixed

voltages of 5.0V, 3.3V, 2.5V, and 1.8V are available on

MIC39100/1 with adjustable output voltages to 1.24V on

MIC39102.

For other voltages, contact Micrel.

Typical Applications

Features

• Fixed and adjustable output voltages to 1.24V

• 410mV typical dropout at 1A

Ideal for 3.0V to 2.5V conversion

Ideal for 2.5V to 1.8V conversion

• 1A 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 SOT-223 package

• Power SO-8 package

Applications

• 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

2.5V

3.3V

10

µF

tantalum

OUT

GND

MIC39100

2.5V/1A Regulator

IN

R1

100k

2.5V

Error

Flag

Output

3.3V

10

µF

tantalum

EN

OUT

FLG

GND

MIC39101

ENABLE

SHUTDOWN

2.5V/1A Regulator with Error Flag

IN

R1

1.5V

2.5V

10

µF

tantalum

R2

EN

OUT

ADJ

GND

MIC39102

ENABLE

SHUTDOWN

1.5V/1A Adjustable Regulator