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