CALIFORNIA MICRO DEVICES
CMPWR100
200mA SmartOR
TM
Regulator with V
AUX
Switch
Features
• Automatic detection of V
CC
input supply
• Fully integrated low impedance switch (0.2Ω typ.)
• Glitch-free output during supply transitions
• 200mA output maximum Load Current
• Foldback current limiting
• Built-in hysteresis during supply selection
• Controller operates from either V
CC
or V
AUX
• 8-pin Narrow SOIC package
Applications
• PCI adapter cards
• Network Interface Cards (NICs)
• Dual Power Systems
• Systems with Standby Capabilities
Product Description
The California Micro Devices’ SmartOR
TM
CMPWR100 is
a low dropout regulator that delivers up to 200mA 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.
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 dynami-
cally switched without loss of output voltage.
A logic output signal, Drive, is active LOW whenever the
internal regulator is disabled.
PIN DIAGRAM, APPLICATION CIRCUIT, AND BLOCK DIAGRAM
Top View
V
CC
V
AUX
V
AUX
GND
1
2
3
4
8
7
6
5
DRIVE
+
CMPWR100
V
CC
C
IN
1µF
+
–
DRIVE
V
OUT
3.3V
200mA
V
OUT
V
OUT
N.C.
V
CC
5V +
V
AUX
V
OUT
GND
+
V
AUX
C
OUT
4µ7
– 3.3V
CMPWR100
8-Pin Plastic SOIC
Pin Diagram
V
CC
DRIVE
+
GND
Typical Application Circuit
DESELECT
4.1C
–
V
REF
3.3V
+
–
ENABLE
V
OUT
3.3V
200mA
0.2Ω
V
AUX
GND
GND
Simplified Block Diagram
© 2000 California Micro Devices Corp. All rights reserved.
10/20/2000
C1430800
215 Topaz Street, Milpitas, California 95035
Tel: (408) 263-3214
Fax: (408) 263-7846
www.calmicro.com
1
CALIFORNIA MICRO DEVICES
ABSOLUTE MAXIMUM RATINGS
Parameter
V
CC
Input Voltage
V
AUX
Input Voltage
Drive Logic Voltage
Storage Termperature Range
Operating Ambient
Operating Junction
Power Dissipation: SOIC
Note 1
Rating
6.0, GND –0.5
4.0, GND –0.5
V
CC
+ 4.0, GND –0.5
–40 to 150
0 to 70
0 to 125
0.5
Unit
V
V
V
˚C
˚C
˚C
W
CMPWR100
O P E R AT I N G C O N D I T I O N S
Parameter
V
CC
V
AUX
Temperature (Ambient)
Load Current
C
EXT
Range
5.0 ± 0.5
3.3 ± 0.3
0 to 70
0 to 200
4.7 ± 10%
Unit
V
V
°C
mA
µF
Symbol
V
OUT
I
OUT
V
CCSEL
V
CCDES
V
CCHYS
I
S/C
R
SWITCH
I
RCC
I
RAUX
V
R LOAD
V
R LINE
I
AUX
I
CC
I
GND
ELECTRICAL OPERATING CHARACTERISTICS
(over operating conditions unless specified otherwise)
Parameter
Conditions
Min
Re g u l a t o r Ou t p u t Vo l t a g e
Regul at or Out put Cur r ent
Se l e c t Vo l t a g e
De s e l e c t Vo l t a g e
Hysteresis Voltage
Shor t Ci r c ui t Out put Cur r ent
Au x i l i a r y Swi t c h Re s i s t a n c e
V
CC
Pin Reverse Leakage
V
AUX
Pin Reverse Leakage
Load Regulation
Line Regulation
V
AUX
Supply Current
V
CC
Supply Current
Ground Pin Current
Note 3
Typ
3.30
4.25
4.10
0.15
150
0.2
2
2
50
50
100
5
800
100
100
800
1000
400
400
1.0
1.0
Max
3.465
4.45
Unit
V
mA
V
mA
200mA > I
LOAD
> 0mA
Regulator Enabled
Regulator Disabled
Hysteresis
Note 2
V
CC
= 5V, V
OUT
= 0V
V
CCDES
> V
CC
, V
AUX
= 3.3V
V
OUT
= 3.3V, V
CC
= 0V
V
OUT
= 0V, V
CC
= 5V
V
CC
= 5V, I
LOAD
= 20mA to 200mA
V
CC
= 4.5V to 5.5V, I
LOAD
= 5mA
V
AUX
> V
CC ,
I
LOAD
= 0mA
V
CC
> V
AUX
V
CC
> V
CCSEL,
I
LOAD
= 0mA
V
CCDES
> V
CC
V
CCDES
> V
CC
V
CC
= V
CCSEL
, I
LOAD
= 5mA
V
CC
= V
CCSEL
, I
LOAD
= 200mA
3.135
200
3.90
0.4
20
20
Ω
µA
µA
mV
mV
µA
µA
µA
600
600
µs
Ω
R
OH
R
OL
t
DH
t
DL
Drive Pull-up Resistance
Drive Pull-down Resistance
Drive High Delay
Drive Low Delay
R
PULLUP
to V
CC
, V
CC
> V
CCSEL
R
PULLDOWN
to GND, V
CCDES
> V
CC
C
DRIVE
=1nF, V
CC
t
RISE
< 100ns
C
DRIVE
=1nF, V
CC
t
FALL
< 100ns
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 0.25Ω 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.
Note 3: Ground pin current consists of controller current (100µA) and regulator current if enabled. The controller always draws 100µA from
either V
CC
or V
AUX
, whichever is greater. All regulator current is supplied exclusively from V
CC
. At high load currents a small increase
occurs due to current limit protection circuitry.
©2000 California Micro Devices Corp. All rights reserved.
2
215 Topaz Street, Milpitas, California 95035
Tel: (408) 263-3214
Fax: (408) 263-7846
www.calmicro.com
10/20/2000
CALIFORNIA MICRO DEVICES
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 (200mA max) will be enabled and
deliver a fixed 3.3V at V
OUT
. When V
CC
falls below V
CCDES
(4.10V typically), the regulator will be disabled.
Internal loading on this pin is typically 0.8mA 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 incor-
porated 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 0.25Ω 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 1µF to 10µF 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 (0.2Ω typically) fully inte-
grated switch.
An internal charge pump operates from V
AUX
and is used
to drive the gate of the Nchannel mosfet auxiliary switch.
CMPWR100
This approach provides excellent switch “on-resistance”
characteristics even under low input voltage conditions.
The internal loading on this pin is typically less than
10mA and will increase to 100µA if V
CC
falls below the
voltage on V
AUX
.
If V
AUX
= 0V, the V
CCDES
voltage is inhibited which pre-
vents the regulator from being disabled.
GND
is the negative reference for all voltages. The
current that flows in the ground connection is very low
(typically 0.8mA) and has minimal variation over all load
conditions.
V
OUT
is the regulator output voltage connection used to
power the load. An output capacitor of 4.7µF 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 logic output signal that reflects the enable/
disable state of the regulator. It may be used to drive the
gate of an external PFET switch in applications that
require auxiliary switch resistances of less than 0.2Ω.
When the regulator is disabled (V
CC
< V
CCDES
), the Drive
pin is pulled LOW to GND. Whenever the regulator is
enabled (V
CC
> V
CCDES
), the Drive output is pulled HIGH
to V
CC
. The sinking and sourcing ability of this output is
equivalent to a 400Ω resistor.
n.c
pins are electrically isolated from the internal
circuitry. These pins can be connected to any external
voltage level without impacting the device functionality
PIN FUNCTIONS
Symbol
V
CC
V
AUX
GND
V
OUT
Drive
n.c.
Description
Positive supply input for regulator. The regulator is disabled whenV
CC
falls below V
CCDES
(4.1V).
Auxiliary supply input. A low impedance internal switch connects this supply to the output when
the regulator is disabled.
Negative reference for all voltages.
Output voltage (3.3V) which is either connected to the regulator (V
CC
> V
CCSEL
) or directly
to the V
AUX
supply (V
CC
< V
CCDES
).
CMOS Logic Output which reflects the Enable/Disable (HIGH/LOW) state of the regulator.
Unconnected pins which are electrically isolated from internal circuitry.
© 2000 California Micro Devices Corp. All rights reserved.
10/20/2000
215 Topaz Street, Milpitas, California 95035
Tel: (408) 263-3214
Fax: (408) 263-7846
www.calmicro.com
3
CALIFORNIA MICRO DEVICES
CMPWR100
Typical DC Characteristics
Unless stated otherwise, all DC characteristics were
measured at room temperature with a nominal V
CC
supply voltage of 5.0 volts and an output capacitance of
4.7µF. All load conditions used were resistive.
By taking the V
AUX
supply input to ground (0V), the
controller will prevent the regulator from being disabled.
This allows the full dropout characteristics of the
regulator to be observed. In normal operation the
regulator is prevented from operating at supply voltages
less than 4.1 volts.
Dropout Characteristics
of the regulator are shown
here. At maximum rated load conditions (200mA), a
100mV drop in regulation occurs when the line voltage
has collapses below 4.1V
VOUT (V)
3.35
3.30
3.25
3.20
3.15
3.10
3.05
3.5
200mA Load
20mA Load
For light load conditions (20mA), regulation is main-
tained for line voltages as low as 3.5V.
In normal operation the regulator is deselected at 4.1V,
which ensures a regulation output drop of less than
100mV is maintained.
4.0
VCC (V)
4.5
5.0
Dropout Characteristics
VOUT (V)
Load regulation
performance is shown from zero to
maximum rated load. A change in load from 10% to
100% of rated, results in an output voltage change of
50mV. This translates into an effective output impedance
of approximately 0.30Ω.
3.40
3.35
3.30
3.25
3.20
0
50
100
Load Current (mA)
150
200
Load Regulation
©2000 California Micro Devices Corp. All rights reserved.
4
215 Topaz Street, Milpitas, California 95035
Tel: (408) 263-3214
Fax: (408) 263-7846
www.calmicro.com
10/20/2000
CALIFORNIA MICRO DEVICES
CMPWR100
Typical DC Characteristics cont’d
Auxiliary Switch resistance
is shown across a range
of V
AUX
supply conditions. The charge pump circuitry
ensures the Nchannel integrated auxiliary switch
remains fully enhanced even at very low input voltages.
0.30
Resistance (Ω)
0.25
0.20
0.15
2.70
3.00
V
AUX
(V)
3.30
3.60
Auxiliary Switch Resistance
Current (mA)
Ground Current
is shown across the entire range of
load conditions. The ground current has minimal varia-
tion across the range of load conditions and shows only
a slight increase at maximum load. The slight increase
at rated load is due to the current limit protection
circuitry becoming active.
1.5
1.0
0.5
0.0
0
50
100
Load Current (mA)
150
200
Ground Current
Supply Current (µA)
Supply Current
for both the V
AUX
input and the V
CC
supply is shown. The internal controller circuit typically
draws around 100µA.
For V
CC
less than V
AUX
, the controller current is supplied
from the auxiliary input and the current drawn from V
CC
is minimal (<10µA).
When V
CC
exceeds V
AUX
but is less than V
CCSEL
(4.25V),
the controller current is supplied by V
CC
.
Once V
CC
exceeds V
CCSEL
, the regulator is enabled and
draws around 800mA. At this point the auxiliary supply
only powers the internal charge pump (<10µA).
1000
VCC
Current
100
VAUX
Current
10
1
2
3
VCC (V)
4
5
V
CC
/V
AUX
SUPPLY CURRENT
(V
AUX
= 3.3v)
© 2000 California Micro Devices Corp. All rights reserved.
10/20/2000
215 Topaz Street, Milpitas, California 95035
Tel: (408) 263-3214
Fax: (408) 263-7846
www.calmicro.com
5
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