CALIFORNIA MICRO DEVICES
CMPWR280
Pin Diagram
1.5A SmartOR
TM
Dual Regulator with V
AUX
Drive
Features
Automatic selection of V
CC
or V
SBY
Drive control signal for external V
AUX
switch
Continuous 3.3V output supply
Glitch-free output during supply transitions
Built-in hysteresis for supply selection
V
CC
regulates up to 1.5A output current
V
SBY
regulates up to 375mA output current
Foldback current limiting
Thermal shutdown with hysteresis
On-chip controller operates from V
CC
, V
SBY
or V
OUT
Applications
Peripheral Component Interface (PCI) Adapter Cards
Network Interface Cards (NICs)
Multiple Powered Systems
Systems with Standby Capabilities
Product Description
The California Micro Devices SmartOR
TM
CMPWR280 is a fully
protected Dual-Input low dropout CMOS regulator that also
provides the necessary control signal for driving an external
auxiliary Pchannel MOSFET switch. The SmartOR
TM
device au-
tomatically selects one of three possible inputs on a priority
basis: V
CC
(1.5A), V
SBY
(375mA) or V
AUX
via the drive signal
used to control an external switch.
V
CC
is given first priority. In the event of the V
CC
supply being
powered down, the device will automatically deselect the V
CC
prior to regulator dropout and immediately select V
SBY
(second
priority) as its power source.
If neither V
CC
nor V
SBY
are present the drive control output will
turn-on an external P-channel MOSFET switch from an auxiliary
3.3V supply V
AUX
to V
OUT
.
All the necessary control circuitry needed to provide a smooth
and automatic transition between all three supplies has been
incorporated. This allows V
CC
to be dynamically switched with-
out loss of output voltage.
The CMPWR280 is internally protected against output
short-circuits, current overload and thermal overload.
Typical Application Circuit
Simplified Electrical Schematic
Pins
5
ST
ANDAR
D PART ORDE RING INFORMATION
Package
Ordering Part Number
Style
Part Marking
TO263
CMPWR280TO
When placing an order please specify desired shipping: Tubes or Tape & Reel.
© 2000 Calirornia Micro Devices Corp. All rights reserved. CMPWR300 is a trademark of California Micro Devices Corp.
3/00
C0660200
215 Topaz Street, Milpitas, California 95035
Tel: (408) 263-3214
Fax: (408) 263-7846
www.calmicro.com
1
CALMIRCO [ CALIFORNIA MICRO DEVICES CORP ]
