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
L
Fax: 408.263.7846
L
www.calmicro.com
1
CM3103
PACKAGE / PINOUT DIAGRAM
TOP VIEW
N.C.
V
CC
V
OUT
V
AUX
1
2
3
4
8
7
6
5
GND
GND
GND
GND
8-pin Power SOIC
Note: This drawing is not to scale.
PIN DESCRIPTIONS
PIN(S)
1
2
NAME
N.C.
V
CC
Positive input supply for the voltage regulator. Whenever this supply voltage exceeds the V
CCSEL
level (4.4V), it will immediately be given priority and be used to power the regulator output. If this
supply voltage falls below the V
CCDES
level (4.2V) it will immediately be deselected and no longer
provide power for the regulator output. An internal hysteresis voltage of 0.2V is used to prevent any
chatter during selection and deselection of V
CC
. The effective source impedance of V
CC
should be
kept below 0.3 ohm to ensure changeover disturbances do not exceed the hysteresis level.
If the connection to V
CC
is made within a few inches of the main input filter, a bypass capacitor may
not be necessary. Otherwise a bypass filter capacitor in the range of 1µF to 10µF will ensure ade-
quate filtering.
Regulator output. Power is provided from the regulator or via the low impedance auxiliary switch.
This output requires a capacitance of 10µF to ensure regulator stability and minimize the peak out-
put disturbance during power supply changeover.
Auxiliary voltage power source. This supply is selected only when V
CC
falls below 4.2V. Under
these conditions an internal switch that provides a very low impedance connection directly between
V
OUT
and V
AUX
is enabled .
The negative reference for all voltages. Also functions as a thermal path for heat dissipation.
DESCRIPTION
3
V
OUT
4
V
AUX
5-8
GND
Ordering Information
PART NUMBERING INFORMATION
Standard FInish
Ordering Part
Pins
8
Package
Power SOIC
Number
1
CM3103-01SA
Part Marking
CM3103SA
Lead-free Finish
Ordering Part
Number
1
CM3103-01SF
Part Marking
CM3103SF
Note 1: Parts are shipped in Tape & Reel form unless otherwise specified.
© 2004 California Micro Devices Corp. All rights reserved.
2
430 N. McCarthy Blvd., Milpitas, CA 95035-5112
L
Tel: 408.263.3214
L
Fax: 408.263.7846
L
www.calmicro.com
01/28/04
CM3103
Specifications
ABSOLUTE MAXIMUM RATINGS
PARAMETER
ESD Protection (HBM)
Pin Input Voltages
V
CC
V
AUX
Storage Temperature Range
Operating Temperature Range
Ambient
Junction
Power Dissipation (See Note 1)
RATING
+2000
[GND - 0.5] to +6.0
[GND - 0.5] to +4.0
-40 to +150
0 to +70
0 to +125
Internally Limited
UNITS
V
V
V
°C
°C
°C
W
Note 1: At rated load, the power dissipation will be 0.68Watt (1.7V x 0.4A). Under these conditions, (in a 70°C ambient), the thermal
resistance from junction to ambient (
θ
JA
) must not exceed 80°C/W. This is typically achieved with 2 square inches of copper
printed circuit board area connected to the GND pins for heat spreading, or equivalent.
STANDARD OPERATING CONDITIONS
PARAMETER
V
CC
V
AUX
Ambient Operating Temperature Range
Load Current
C
EXT
VALUE
5.0 +0.25
3.3 +0.3
0 to +70
0 to 400
10 +20%
UNITS
V
V
°C
mA
µF
© 2004 California Micro Devices Corp. All rights reserved.
01/28/04
430 N. McCarthy Blvd., Milpitas, CA 95035-5112
L
Tel: 408.263.3214
L
Fax: 408.263.7846
L
www.calmicro.com
3
CM3103
ELECTRICAL OPERATING CHARACTERISTICS
(SEE NOTE 1)
SYMBOL
V
OUT
I
LIM
I
S/C
V
R LOAD
V
R LINE
V
CCSEL
V
CCDES
V
HYST
R
SW
I
RCC
I
RAUX
I
CC
I
AUX
I
GND
PARAMETER
Regulator Output Voltage
Regulator Current Limit
Short Circuit Current
Load Regulation
Line Regulation
xx
V
CC
Select Voltage
V
CC
Deselect Voltage
Hysteresis Voltage
V
AUX
Switch Resistance
V
CC
Reverse Leakage
V
AUX
Reverse Leakage
V
CC
Supply Current
V
AUX
Supply Current
Ground Current
One supply input taken to GND while the others
remain at nominal voltage.
V
CC
> V
CCSEL
, I
LOAD
=0mA
V
AUX
is selected, I
LOAD
=0mA
V
AUX
is selected, (V
CC/SBY
= 0V)
V
CC/SBY
= 5V, I
LOAD
= 0mA
V
CC/SBY
= 5V, I
LOAD
= 400mA
CONDITIONS
0mA < I
LOAD
< 400mA
V
OUT
> 0V
V
CC
=5V, V
OUT
< 0V
V
CC
=5V, 5mA < I
LOAD
< 400mA
I
LOAD
= 5mA; 4.5V < V
IN
< to 5.5V
V
AUX
present
V
AUX
present
V
AUX
present; See Note 2
4.00
MIN
3.135
410
TYP
3.300
500
150
20
2
4.40
4.20
0.20
0.25
5
0.8
0.20
0.20
0.80
1.00
160
20
0.40
100
1.5
0.30
0.30
1.50
2.00
4.60
MAX
3.465
UNITS
V
mA
mA
mV
mV
V
V
V
Ω
µA
mA
mA
mA
mA
mA
°C
°C
T
DISABLE
T
HYST
Shutdown Temperature
Thermal Hysteresis
Note 1: Operating characteristics are over Standard Operating Conditions unless otherwise specified.
Note 2: The disturbance on V
CC
during supply changeover should be kept below the hysteresis voltage to prevent any chatter. The
source resistance on the V
CC
supply should be kept to less than 0.3 ohms to ensure precise switching.
© 2004 California Micro Devices Corp. All rights reserved.
4
430 N. McCarthy Blvd., Milpitas, CA 95035-5112
L
Tel: 408.263.3214
L
Fax: 408.263.7846
L
www.calmicro.com
01/28/04
CM3103
Performance Information
CM3103 Typical DC Characteristics (nominal conditions unless specified otherwise)
V
CC
Supply Current vs. Voltage
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
0
1
2
3
4
V
CC
Input Voltage [V]
5
6
0.5
V
AUX
Supply Current vs. Voltage
Supply Current [mA]
Supply Current [mA]
0.4
0.3
0.2
0.1
0.0
0
1
2
3
V
AUX
Input Voltage [V]
4
Ground Current vs. Output Load
Line Regulation
3.4
1.2
1.1
1.0
0.9
0.8
0.7
0.6
0
100
200
300
Load Current [mA]
400
Regulator Output Voltage [V]
Ground Current [mA]
3.3
5mA
3.2
400mA
3.1
3.0
3.5
4
4.5
5
Line Voltage [V]
5.5
6
© 2004 California Micro Devices Corp. All rights reserved.
01/28/04
430 N. McCarthy Blvd., Milpitas, CA 95035-5112
L
Tel: 408.263.3214
L
Fax: 408.263.7846
L
www.calmicro.com
5
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