© 2000 Calirornia Micro Devices Corp. All rights reserved.

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215 Topaz Street, Milpitas, California 95035

Tel: (408) 263-3214

Fax: (408) 263-7846

www.calmicro.com

CALIFORNIA MICRO DEVICES

CMPWR280

1

Features

• Automatic selection of V

• Drive control signal for external V

• Continuous 3.3V output supply

• Glitch-free output during supply transitions

• Built-in hysteresis for supply selection

•V

•V

• Foldback current limiting

• Thermal shutdown with hysteresis

• On-chip controller operates from V

Applications

• Peripheral Component Interface (PCI) Adapter Cards

• Network Interface Cards (NIC’s)

• Multiple Powered Systems

• Systems with Standby Capabilities

Product Description

protected Dual-Input low dropout CMOS regulator that also

provides the necessary control signal for driving an external

tomatically selects one of three possible inputs on a priority

basis: V

used to control an external switch.

V

powered down, the device will automatically deselect the V

CC

prior to regulator dropout and immediately select V

priority) as its power source.

If neither V

turn-on anexternal P-channel MOSFETswitchfromanauxiliary

3.3V supply V

All the necessary control circuitry needed to provide a smooth

and automatic transition between all three supplies has been

incorporated. This allows V

out loss of output voltage.

The CMPWR280 is internally protected against output

short-circuits, current overload and thermal overload.

CMPWR300™ is a trademark of California Micro Devices Corp.

Pin Diagram

Typical Application Circuit

Simplified Electrical Schematic

When placing an order please specify desired shipping: Tubes or Tape & Reel.

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