CALIFORNIA MICRO DEVICES
CMPWR025
Dual Input SmartOR™ Power Switch
FEATURES
• Automatically selects V
CC1
OR V
CC2
input source
• Integrated low impedance switches (0.2Ω TYP)
• Operating supply range from 2.8V to 5.5V
• Glitch-free output during supply switching
transitions
• Low operating supply current of 20µA (TYP)
• User-selectable hysteresis for supply selection
• 8-pin SOIC Narrow or 8-pin MSOP packages
APPLICATIONS
• PCI cards for Wake-On-LAN/Wake-On-Ring
• Dual power systems
• Systems with standby capabilities
• Battery backup systems
• See Application Note AP211
PRODUCT DESCRIPTION
California Micro Devices’ SmartOR™ CMPWR025 is a
dual input power switch that selects between two
different power inputs and delivers it to one output. The
device integrates two very low impedance power
switches and automatically implements an OR function
that selects the higher of the two inputs. A hysteresis is
built in (and is user selectable) to prevent switch chatter.
The CMPWR025 is a much-improved solution to simply
ORing two diodes, due to the greatly reduced losses of
the CMPWR025 when compared to low forward drop
Schottky diodes.
The CMPWR025 is designed to operate above the 1W
(375mA at 3.3V) sleep mode rating stated in the PCI
Rev 2.2 spec. In fact the CMPWR025 current rating is
dependent upon the power dissipation resulting from the
voltage drop across the internal switch elements. See
the Typical DC Characteristics section in this data sheet
for details.
For IAPC (Instantly Available Personal Computer)
applications see the CAMD Applications Note AP211
“Instantly Available PCI Card Power Management”.
PIN DIAGRAM, TYPICAL APPLICATION CIRCUIT, AND SIMPLIFIED BLOCK DIAGRAM
Top View
V
CC1
V
CC1
V
CC2
V
CC2
1
2
3
4
8
7
6
5
HYS
V
OUT
V
OUT
GND
+
–
CMPWR025
V
CC1
V
CC2
V
CC1
5V
+
V
OUT
V
OUT
+
HYS
GND
V
CC2
5V
–
C
OUT
10µF
CMPWR025
8-Pin SOIC Narrow and MSOP Package
Pin Diagram
GND
SW1
0.2Ω
V
CC1
+
–
Typical Application Circuit
GND
SW2
0.2Ω
V
OUT
V
CC2
HYS
GND
GND
GND
Simplified Block Diagram
© 2000 California Micro Devices Corp. All rights reserved.
10/18/2000
C0970500
215 Topaz Street, Milpitas, California 95035
Tel: (408) 263-3214
Fax: (408) 263-7846
www.calmicro.com
1
CALMIRCO [ CALIFORNIA MICRO DEVICES CORP ]
