CALIFORNIA MICRO DEVICES

© 2001 California Micro Devices Corp. All rights reserved. SmartOR™ is a trademark of California Micro Devices Corporation.

3/6/2001

1

215 Topaz Street, Milpitas, California 95035



Tel: (408) 263-3214

Fax: (408) 263-7846

www.calmicro.com

CMPWR101

Features

• Automatic detection of V

• Glitch-free output during supply transitions

• Built-in hysteresis during supply selection

• 250mA output maximum load current

• Fully integrated V

• Overload current protection

• Short circuit current protection

• Operates from either V

• 8-pin SOIC package

Product Description

a low dropout regulator that delivers up to 250mA of load

current at a fixed 3.3V output. An internal threshold level

(typically 4.1V) is used to prevent the regulator from

being operated below dropout voltage. The device

continuously monitors the input supply and will automati-

cally disable the regulator when V

threshold level. When the regulator is disabled, a low

impedance, fully integrated switch is enabled which

allows the output to be directly powered from an auxil-

iary 3.3V supply.

Applications

• PCI adapter cards

• Network Interface Cards (NIC’s)

• Dual power systems

• Systems with standby capabilities

C1660101

Pin Diagram

When V

old, the low impedance switch is disabled and the

regulator is once again enabled.

All the necessary control circuitry needed to provide a

smooth and automatic transition between the supplies

has been incorporated. This allows V

switched without loss of output voltage.

An output logic signal, DRIVE, is active LOW whenever

the internal regulator is disabled.

PIN DIAGRAM AND APPLICATION CIRCUIT

STANDARD PART ORDERING INFORMATION

Package

Ordering Part Number

Pins

Style

Tubes

Tape & Reel

Part Marking

8

SOIC

CMPWR101S/T

CMPWR101S/R

CMPWR101S

NC

Top View

CMPWR101

8-Pin SOIC

GND

5

4

6

3

7

2

DRIVE

8

1

Typical Application Circuit

5V

GND

GND

DRIVE

3.3V

250mA

CMPWR101

3.3V

4µF

+

–

+

–

1µF

+

+