September 2004

1

M9999-091604

MIC37100/37101/37102

Micrel

MIC37100/37101/37102

1A Low-Voltage

µµµµµCap LDO Regulator

General Description

The MIC37100, MIC37101, and MIC37102 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

MIC37100/01/02 offers extremely low dropout (typically

280mV at 1A) and low ground current (typically 11mA at 1A).

The MIC37100 is a fixed output regulator offered in the

SOT-223 package. The MIC37101 and MIC37102 are fixed

and adjustable regulators, respectively, in a thermally en-

hanced power 8-lead SOIC (small outline package) and the

SOT-223 package. The MIC37102 is also available in the S-

PAK power package, for applications that require higher

power dissipation or higher operating ambient temperatures.

The MIC37100/01/02 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 or lower. A guaranteed maximum dropout voltage of

500mV over all operating conditions allows the

MIC37100/01/02 to provide 2.5V from a supply as low as 3V

and 1.8V from a supply as low as 2.3V.

The MIC37100/01/02 is fully protected with overcurrent lim-

iting and thermal shutdown. Fixed output voltages of 1.5V,

1.65V, 1.8V, 2.5V and 3.3V are available on MIC37100/01

with adjustable output voltages to 1.24V on MIC37102.

For other voltages, contact Micrel.

All support documentation can be found on Micrel’s web

site at www.micrel.com.

Typical Applications

Features

• Fixed and adjustable output voltages to 1.24V

•

µµµµµCap Regulator, 10µµµµµF ceramic output capacitor

stable

• 280mV typical dropout at 1A

Ideal for 3.0V to 2.5V conversion

Ideal for 2.5V to 1.8V, 1.65V or 1.5V conversion

• 1A minimum guaranteed output current

• 1% initial accuracy

• Low ground current

• Current limiting and thermal shutdown

• Reversed-leakage protection

• Fast transient response

• Low-profile SOT-223 package

• Power SO-8 package

• S-PAK package (MIC37102 only)

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 registered trademark of Micrel, Inc.

PowerPC is a trademark of IBM Corporation.

Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com

IN

2.5V

3.3V

10

µF

ceramic

OUT

GND

MIC37100

2.5V/1A Regulator

0

50

100

150

200

250

300

350

0

0.25

0.5

0.75

1

OUTPUT CURRENT (A)

Dropout

vs. Output Current

2.5V

OUT

3.3V

OUT