CALIFORNIA MICRO DEVICES
CMPWR101
250mA SmartOR
TM
Regulator with V
AUX
Switch
Features
• Automatic detection of V
CC
input supply
• Glitch-free output during supply transitions
• Built-in hysteresis during supply selection
• 250mA output maximum load current
• Fully integrated V
AUX
switch
• Overload current protection
• Short circuit current protection
• Operates from either V
CC
or V
AUX
• 8-pin SOIC package
Applications
• PCI adapter cards
• Network Interface Cards (NIC’s)
• Dual power systems
• Systems with standby capabilities
Product Description
The California Micro Devices’ SmartOR
TM
CMPWR101 is
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
CC
falls below the
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.
When V
CC
is restored to a level above the select thresh-
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
CC
to be dynamically
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
Top View
V
CC
V
AUX
V
AUX
GND
1
2
3
4
8
7
6
5
DRIVE
V
OUT
V
OUT
NC
+
CMPWR101
V
CC
C
IN
1µF
+
DRIVE
V
OUT
3.3V
250mA
V
CC
5V
+
–
V
AUX
V
OUT
GND
V
AUX
3.3V
–
+
C
OUT
4µF
GND
CMPWR101
8-Pin SOIC
Pin Diagram
Typical Application Circuit
STANDARD PART ORDERING INFORMATION
Package
Pins
8
Style
SOIC
Ordering Part Number
Tubes
Tape & Reel
CMPWR101S/T
CMPWR101S/R
Part Marking
CMPWR101S
© 2001 California Micro Devices Corp. All rights reserved. SmartOR™ is a trademark of California Micro Devices Corporation.
C1660101
215 Topaz Street, Milpitas, California 95035
3/6/2001
Tel: (408) 263-3214
Fax: (408) 263-7846
www.calmicro.com
1
CALMIRCO [ CALIFORNIA MICRO DEVICES CORP ]
