CM3103
400mA SmartOR
TM
Regulator with V
AUX
Switch
Features
•
•
•
•
•
•
•
•
Continuous 3.3V / 400mA output from two inputs
Complete Power Management solution
Built-in hysteresis when selecting input supplies
Integrated switch featuring low RDS
ON
(0.25Ω
typ.)
Foldback current limiting protection
Thermal overload shutdown protection
8-pin SOIC package
Lead-free version available
Product Description
The CM3103 combines a fixed voltage regulator and a
V
AUX
switch in a single 8-pin SOIC package. The volt-
age regulator is capable of delivering up to 400mA con-
tinuously at 3.3V. The output power is provided from
two independent input voltage sources on a prioritized
basis. Power is always taken in priority of V
CC
, then
V
AUX
.
When V
CC
(5V) is present, the device automatically
enables the regulator, producing a stable 3.3V output
at V
OUT
, while disabling the V
AUX
switch.
When only V
AUX
(3.3V) is present, the device provides
a low impedance direct connection (0.25Ω typ.) from
V
AUX
to V
OUT
.
All the necessary control circuitry needed to provide a
smooth and automatic transition between both supplies
has been incorporated. This allows the V
CC
input sup-
ply to be dynamically switched without loss of output
voltage.
The CM3103 is available with optional lead-free finish-
ing.
Applications
•
•
•
•
PCI adapter cards with Wake-On-LAN
Network Interface Cards (NICs)
Multiple power supply systems
Systems with standby capabilities
Typical Application Circuit
Simplified Electrical Schematic
CM3103
V
CC
V
CC
5V
+
C
IN
V
AUX
3.3V
1
µ
F
V
CC
V
OUT
3.3V/400mA
+
Enable
V
OUT
Vdeselect
-
V
AUX
GND
4.2V
AuxSw
Controller
3.3V
+
+
C
EXT
10
µ
F
V
AUX
GND
AuxSw
0.25Ω
-
Regulator Amp
V
OUT
GND
© 2004 California Micro Devices Corp. All rights reserved.
01/28/04
430 N. McCarthy Blvd., Milpitas, CA 95035-5112
L
Tel: 408.263.3214
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Fax: 408.263.7846
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www.calmicro.com
1
CALMIRCO [ CALIFORNIA MICRO DEVICES CORP ]
