Power Regulator

CMPWR150

©2010 SCILLC. All rights reserved.

Publication Order Number:

June 2010 Rev. 3

CMPWR150/D

Features

•

Automatic detection of V

•

Drive output logic to control external switch

•

Glitch-free output during supply transitions

•

500mA output maximum load current

•

Built-in hysteresis during supply selection

•

Controller operates from either V

•

8-pin Power SOIC thermal package

•

RoHS compliant (lead-free) finishing

Applications

•

PCI adapter cards

•

Network Interface Cards (NICs)

•

Dual power systems

•

Systems with standby capabilities

•

USB powered devices such as printers,

scanners, MP3 players and Zip drives

•

See Application Note AP-211

Product Description

The

CMPWR150 is a low dropout regulator that

delivers up to 500mA 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 automatically

disable the regulator when V

CC

falls below the

threshold level. When the regulator is disabled, the

control signal “Drive” (Active Low) is enabled, which

allows an external PMOS switch to power the load

from an auxiliary 3.3V supply.

When V

CC

is restored to a level above the select

threshold, the control signal for the external PMOS

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

be dynamically switched without loss of output

voltage.

The CMPWR150 is housed in an 8-pin SOIC

thermally enhanced package which is ideal for space

critical applications. The CMPWR150 is available

with RoHS compliant lead-free finishing.