CALIFORNIA MICRO DEVICES
2001 California Micro Devices Corp. All rights reserved. SmartORTM is a trademark of California Micro Devices Corporation.
3/6/2001
1
215 Topaz Street, Milpitas, California 95035
Tel: (408) 263-3214 Fax: (408) 263-7846 www.calmicro.com
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
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.
Applications
PCI adapter cards
Network Interface Cards (NIC's)
Dual power systems
Systems with standby capabilities
C1660101
Pin Diagram
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
STANDARD PART ORDERING INFORMATION
Package
Ordering Part Number
Pins
Style
Tubes
Tape & Reel
Part Marking
8
SOIC
CMPWR101S/T CMPWR101S/R CMPWR101S
NC
Top View
CMPWR101
8-Pin SOIC
GND
5
4
V
OUT
V
AUX
6
3
V
OUT
V
AUX
7
2
DRIVE
V
CC
8
1
Typical Application Circuit
V
CC
V
CC
5V
V
AUX
GND
GND
DRIVE
V
OUT
V
OUT
3.3V
250mA
CMPWR101
V
AUX
3.3V
4F
+
+
C
IN
1F
C
OUT
+
+
CALIFORNIA MICRO DEVICES
2001 California Micro Devices Corp. All rights reserved. SmartORTM is a trademark of California Micro Devices Corporation.
3/6/2001
215 Topaz Street, Milpitas, California 95035
Tel: (408) 263-3214 Fax: (408) 263-7846 www.calmicro.com
2
CMPWR101
Note 1: The power rating is based on a printed circuit board heat spreading capability equivalent to 2 square inches of copper connected to
the GND pins. Typical multi-layer boards using power plane construction will provide this heat spreading ability without the need for
additional dedicated copper area. (Please consult with factory for thermal evaluation assistance).
Note 2: The hysteresis defines the maximum level of acceptable disturbance on V
CC
during switching. It is recommended that the V
CC
source impedance be kept below 0.25
to ensure the switching disturbance remains below the hysteresis during select/deselect
transitions. An input capacitor may be required to help minimize the switching transient.
ABSOLUTE MAXIMUM RATINGS
Parameter
Rating
Unit
ESD Protection (HBM)
2000
V
V
CC,
V
OUT
Voltages
6.0, GND 0.5 V
Drive Logic Voltage
V
CC
+ 0.5, GND 0.5 V
V
AUX
Input Voltage
4.0, GND 0.5 V
Temperature: Storage
40 to 150
C
Operating Ambient
0 to 70
C
Operating Junction
0 to 125
C
Power Dissipation
(Note 1)
0.5
W
OPERATING CONDITIONS
Parameter
Range
Unit
V
CC
5 0.5
V
V
AUX
3.3 0.3
V
Temperature (Ambient)
0 to 70
C
Load Current
0 to 250
mA
C
EXT
4.7 20%
F
ELECTRICAL OPERATING CHARACTERISTICS
(over operating conditions unless specified otherwise)
Symbol
Parameter
Conditions
MIN
TYP
MAX
UNIT
V
OUT
Regulator Output Voltage
0mA < I
LOAD
< 250mA
3.135
3.30
3.465
V
I
LIM
Regulator
Current
Limit
275
mA
V
CCSEL
Select Voltage
Regulator Enabled
4.30
4.45
V
V
CCDES
Deselect
Voltage
Regulator Disabled
3.90 4.10
V
V
CCHYST
Hysteresis
Voltage
(Note 2)
Hysteresis
0.20
V
V
R LOAD
Load Regulation
V
CC
= 5V,
I
LOAD
= 5 to 250mA
20
mV
V
R LINE
Line
Regulation
V
CC
= 4.5V to 5.5V,
I
LOAD
= 5mA
2
mV
R
SWITCH
Auxiliary
Switch
Resistance V
CCDES
> V
CC
, V
AUX
= 3.3V
0.25
0.4
I
RCC
V
CC
Pin Reverse Leakage
V
AUX
= 3.3V, V
CC
= 0V
2
50
A
I
RAUX
V
AUX
Pin Reverse Leakage
V
AUX
= 0V, V
CC
= 5V
2
50
A
I
GND
Ground
Current
V
CC
< V
CCDES
, I
LOAD
= 0mA
0.2
0.4
mA
V
CC
> V
CCSEL
, I
LOAD
= 0mA
0.6
1.0
mA
V
CC
> V
CCSEL
, I
LOAD
= 250mA
0.7 1.2 mA
I
AUX
V
AUX
Supply Current
V
AUX
> V
CC
0.2
0.4
mA
V
CC
> V
AUX
0.02
0.1
mA
R
OH
Drive
Pull-up
Resistance
R
PULLUP
to V
CC,
V
CC
> V
CCSEL
4.0
8.0 k
R
OL
Drive
Pull-down
Resistance
R
PULLDOWN
to GND, V
CCDES
> V
CC
0.1 0.4 k
CALIFORNIA MICRO DEVICES
2001 California Micro Devices Corp. All rights reserved. SmartORTM is a trademark of California Micro Devices Corporation.
3/6/2001
3
215 Topaz Street, Milpitas, California 95035
Tel: (408) 263-3214 Fax: (408) 263-7846 www.calmicro.com
CMPWR101
Interface Signals
V
CC
is the power source for the internal regulator and is
monitored continuously by an internal controller circuit.
Whenever V
CC
exceeds V
CCSEL
(4.25V typically), the
internal regulator will be enabled and deliver a fixed
3.3V at V
OUT
. When V
CC
falls below V
CCDES
(4.10V typi-
cally), the regulator will be disabled.
Internal loading on this pin is typically 0.6mA when the
regulator is enabled, which reduces to 0.1mA whenever
the regulator is disabled. If V
CC
falls below the voltage on
the V
AUX
pin, the V
CC
loading will further reduce to only a
few microamperes.
During a V
CC
power-up or power-down sequence, there
will be an effective step increase in V
CC
line current
when the regulator is enabled/disabled. This line current
transient will cause a voltage disturbance at the V
CC
pin.
The magnitude of the disturbance will be directly
proportional to the effective power supply source
impedance being delivered to the V
CC
input.
A built-in hysteresis voltage of 150mV has been
incorporated to minimize any chatter during supply
changeover. It is recommended that the power supply
connected to the V
CC
input should have a source
resistance of less than 0.25
to minimize the event of
chatter during the enabling/disabling of the regulator.
If the V
CC
pin is within a few inches of the main input
filter, a capacitor may not be necessary. Otherwise an
input filter capacitor in the range of 1F to 10F will help
to lower the effective source impedance.
V
AUX
is the auxiliary power source. When selected,
(V
CC
< V
CCDES
), the auxiliary supply is directly connected
to V
OUT
, via the low impedance (0.3
typically) fully
integrated switch.
The internal loading on this pin is typically less than
10A and will increase to 100A if V
CC
falls below the
voltage on V
AUX
.
When V
AUX
= 0V, the V
CCDES
voltage is inhibited which
prevents the regulator from being disabled.
V
OUT
is the regulator output voltage connection used to
power the load. An output capacitor of 4.7F is used to
provide the necessary phase compensation, thereby
preventing oscillation. The capacitor also helps to
minimize the peak output disturbance during power
supply changeover.
DRIVE is a CMOS output logic signal (Active Low)
referenced to the V
CC
supply. This output is taken low
whenever the internal regulator is not enabled. This
output is intended only as a control signal for external
circuitry.
GND is the negative reference for all voltages. The
current that flows in the ground connection is very low
(typically 0.6mA) and has minimal variation over all load
conditions.
NC is an unconnected pin which is electrically isolated
from the internal circuitry.
PIN FUNCTIONS
Pin
Symbol
Description
1
V
CC
Positive (5V) supply input for regulator. (V
CC
> V
CCSEL
)
2,
3
V
AUX
Auxiliary supply input is connected directly to the output via a low impedance
when the regulator is disabled.
6,
7
V
OUT
Continuous output voltage (3.3V) is derived from either the internal regulator or low impedance
switch connected to the auxiliary supply input.
8
DRIVE
Output Control Signal which is taken LOW whenever V
CC
is unavailable
4
GND
Negative reference for all voltages
5
NC
Unconnected pin which is electrically isolated from internal circuitry.
Simplified Electrical Schematic
V
OUT
3.3V
250mA
+
V
CC
+
V
DESELECT
4.1V
V
AUX
3.3V
GND
0.2
DRIVE
ENABLE
V
REF
3.3V
CALIFORNIA MICRO DEVICES
2001 California Micro Devices Corp. All rights reserved. SmartORTM is a trademark of California Micro Devices Corporation.
3/6/2001
215 Topaz Street, Milpitas, California 95035
Tel: (408) 263-3214 Fax: (408) 263-7846 www.calmicro.com
4
CMPWR101
Typical DC Characteristics (nominal conditions unless specified otherwise)
Figure 1. Supply Current vs Voltage (V
AUX
= 3.3V)
Figure 2. Switch Resistance vs Supply Voltage
0.20
0.22
0.24
0.26
0.28
0.30
0.32
0.34
2.7
3.0
3.3
3.6
Auxiliary Supply Voltage (V)
Resistance (
)
Figure 3. Ground Current vs Output Load
Figure 4. Line Regulation (1% and 100% rated load)
Figure 5. Load Regulation
Figure 6. Dropout Voltage with Load Current
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0
100
200
300
Load Current (mA)
Gr
ound Current (mA)
3.10
3.15
3.20
3.25
3.30
3.35
3.40
3.0
3.5
4.0
4.5
5.0
5.5
Supply Voltage (V)
5mA Load
250mA Load
Regulator Output (V)
3.25
3.26
3.27
3.28
3.29
3.30
3.31
3.32
3.33
0
100
200
300
400
Load Current (mA)
V
OUT
(V)
0.0
0.2
0.4
0.6
0.8
1.0
1.2
0
100
200
300
400
Load Current (mA)
V
OUT
(V)
0
1
2
3
4
5
6
V
CC
Supply Voltage (V)
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
V
CC
Suppl
y Current (A)
CALIFORNIA MICRO DEVICES
2001 California Micro Devices Corp. All rights reserved. SmartORTM is a trademark of California Micro Devices Corporation.
3/6/2001
5
215 Topaz Street, Milpitas, California 95035
Tel: (408) 263-3214 Fax: (408) 263-7846 www.calmicro.com
CMPWR101
Typical Transient Characteristics (Supply source resistance set to 0.2
)
Figure 7. V
CC
Cold start Power Up (V
AUX
= 0V)
500mV
Drive
(200mA Load)
(V
AUX
= 0V)
V
CC
V
OUT
M 2ms
1V
Ch2
5V
3
Ch3
1V
Tek Run: 25kS/s Sample
Ch1
4.66V
Drive
(200mA Load)
(V
AUX
= 0V)
V
CC
V
OUT
1V
Ch2
5V
3
Ch3
1V
Tek Run: 25kS/s Sample
Ch1
M 2ms
Figure 8. V
CC
Complete Power Down (V
AUX
= 0V)
2.5V
Drive
V
CC
(offset = 4.3V)
V
OUT
(offset = 3.3V)
100mV
Ch2
5V
3
2
Ch3
100mV
2.5MS/s
Tek 1
Acqs
Ch1
M 20s
Figure 9. V
CC
Power up (V
AUX
= 3.3V)
Figure 10. V
CC
Power Down (V
AUX
= 3.3V)
2.5V
Drive
V
CC
(offset = 4.3V)
V
OUT
(offset = 3.3V)
100mV
Ch2
5V
3
2
Ch3
100mV
2.5MS/s
Tek 1
Acqs
Ch3
M 20s
Figure 11. Load Transient (10% to 90%) Step Response
Figure 12. Line Transient (1Vpp) Step Response
2.08V
V
CC
(offset = 3.3V)
25mA to 225mA
Load Step
20mV
Ch2
2
2V
5MS/s
Tek 3
Acqs
Ch2
M 20s
5.01V
V
CC
(offset = 5.0V)
V
OUT
(offset = 3.3V)
(5mA Load)
1V Step(4.5V to 5.5V)
20mV
Ch2
2
500mV
1MS/s
Tek 1
Acqs
Ch2
M 100s
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