CM3103 Datasheet, PDF (1/10 Pages) California Micro Devices Corp – 400mA SMARTOR REGULATOR Vaux SWITCH

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
Applications
• PCI adapter cards with Wake-On-LAN
• Network Interface Cards (NICs)
• Multiple power supply systems
• Systems with standby capabilities
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.
Typical Application Circuit
Simplified Electrical Schematic
V_CC
V_AUX
5V
+ ^CIN
3.3V ^1µF
CM3103
V_CC
3.3V/400mA
V_OUT
V_AUX
GND
+ ^CEXT
10µF
V_CC
V_OUT
+
Vdeselect
-
4.2V
Controller
Enable
AuxSw
V_AUX
AuxSw
0.25Ω
3.3V
+
-
Regulator Amp
GND
GND
V_OUT
© 2004 California Micro Devices Corp. All rights reserved.
01/28/04 430 N. McCarthy Blvd., Milpitas, CA 95035-5112 L Tel: [phone] L Fax: [phone] L www.calmicro.com
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