Semiconductor Components Industries, LLC, 2001
February, 2001 Rev. 0
1
Publication Order Number:
NCP4555/D
NCP4555, NCP4586
100 mA and 150 mA CMOS
LDOs with Shutdown and
Error Output
The NCP4555 and NCP4586 are high accuracy (typically
"0.5%)
CMOS upgrades for older (bipolar) low dropout regulators. Designed
specifically for batteryoperated systems, the devices' CMOS
construction eliminates wasted ground current, significantly
extending battery life. Total supply current is typically 50
A at full
load (20 to 60 times lower than in bipolar regulators).
The devices' key features include ultra low noise operation, very
low dropout voltage typically 180 mV (NCP4555) and 270 mV
(NCP4586) at full load and fast response to step changes in load. An
error output (ERROR) is asserted when the devices are
outofregulation (due to a low input voltage or excessive output
current). ERROR can be used as a low battery warning or as a
processor RESET signal (with the addition of an external RC
network). Supply current is reduced to 0.5
A (max) and both V
OUT
and ERROR are disabled when the shutdown input is low. The devices
incorporate both overtemperature and overcurrent protection.
The NCP4555 and NCP4586 are stable with an output capacitor of
only 1.0
F and have a maximum output current of 100 mA and
150 mA, respectively. For higher output current regulators, please see
the NCP4569 (I
OUT
= 300 mA) data sheet.
Features
Zero Ground Current for Longer Battery Life
Very Low Dropout Voltage
Guaranteed 100 mA and 150 mA Output
(NCP4555 and NCP4586 Respectively)
High Output Voltage Accuracy
Standard or Custom Output Voltages
PowerSaving Shutdown Mode
ERROR Output Can Be Used as a Low Battery Detector, or
Processor Reset Generator
OverCurrent and OverTemperature Protection
SpaceSaving 5Pin SOT23A Package
Pin Compatible Upgrades for Bipolar Regulators
Applications
BatteryOperated Systems
Portable Computers
Medical Instruments
Instrumentation
Cellular/GSMS/PHS Phones
Linear PostRegulators for SMPS
Pagers
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SOT23
SN SUFFIX
CASE 1212
1
PIN CONNECTIONS
2
3
4
5
See detailed ordering and shipping information in the package
dimensions section on page 11 of this data sheet.
ORDERING INFORMATION
See general marking information in the device marking
section on page 11 of this data sheet.
DEVICE MARKING INFORMATION
5
1
2
4
3
V
IN
ERROR
GND
SHDN
V
OUT
(Top View)
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2
Figure 1. Typical Application
NCP4555
NCP4586
1
2
3
5
4
V
IN
GND
SHDN
ERROR
V
OUT
ERROR
V
OUT
+
1
F
V
IN
1 M
Shutdown Control (from Power Control Logic)
ABSOLUTE MAXIMUM RATINGS*
Rating
Symbol
Value
Unit
Input Voltage
6.5
V
Output Voltage
0.3 to V
IN
+ 0.3
V
Power Dissipation
Internally Limited
Operating Temperature Range
T
A
40
t
T
J
t
125
C
Storage Temperature
T
stg
65 to +150
C
Maximum Voltage on any Pin
V
IN
+ 0.3 to 0.3
V
Lead Temperature (Soldering, 10 Sec.)
+260
C
ESD Withstand Voltage
Human Body Model (Note 1.)
V
ESD
u
2000
V
LatchUp Performance (Note 2.)
Positive
Negative
I
LATCHUP
250
u
500
mA
*Stresses above those listed under "Absolute Maximum Ratings'' may cause permanent damage to the device. These are stress ratings only
and functional operation of the device at these or any other conditions above those indicated in the operation sections of the specifications
is not implied. Exposure to Absolute Maximum Rating conditions for extended periods may affect device reliability.
1. Tested to EIA/JESD22A114A
2. Tested to EIA/JESD78
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3
ELECTRICAL CHARACTERISTICS
(V
IN
= V
OUT
+ 1.0 V, I
L
= 100
A, C
L
= 3.3
F, SHDN
u
V
IH
, T
A
= 25
C, unless otherwise
noted. Boldface type specifications apply for junction temperatures of 40
C to +125
C.)
Characteristics
Test Conditions
Symbol
Min
Typ
Max
Unit
Input Operating Voltage
V
IN
6.0
V
Maximum Output Current
NCP4555
NCP4586
I
OUTMAX
100
150
mA
Output Voltage
Note 3.
V
OUT
V
R
2.5%
V
R
"
0.5%
V
R
+ 2.5%
V
V
OUT
Temperature Coefficient
Note 4.
TCV
OUT
20
40
ppm/
C
Line Regulation
(V
R
+ 1.0 V)
v
V
IN
v
6.0 V
D
V
OUT
/
D
V
IN
0.05
0.35
%
Load Regulation
NCP4555
NCP4586
I
L
= 0.1 mA to I
OUTMAX
I
L
= 0.1 mA to I
OUTMAX
Note 5.
D
V
OUT
/V
OUT
0.5
0.5
2.0
3.0
%
Dropout Voltage
NCP4555, NCP4586
NCP4586
I
L
= 100
A
I
L
= 20 mA
I
L
= 50 mA
I
L
= 100 mA
I
L
= 150 mA
Note 6.
V
IN
V
OUT
2.0
65
85
180
270
120
250
400
mV
Supply Current (Note 10.)
SHDN = V
IH
, I
L
= 0
I
IN
50
80
A
Shutdown Supply Current
SHDN = 0 V
I
INSD
0.05
0.5
A
Power Supply Rejection Ratio
F
RE
v
1.0 kHz
PSRR
64
dB
Output Short Circuit Current
V
OUT
= 0 V
I
OUTSC
300
450
mA
Thermal Regulation
Notes 7., 8.
D
V
OUT
/
D
P
D
0.04
V/W
Thermal Shutdown Die
Temperature
T
SD
160
C
Thermal Shutdown Hysteresis
D
T
SD
10
C
Output Noise
I
L
= I
OUTMAX
470 pF from Bypass to GND
eN
260
nV
Hz
SHDN Input
SHDN Input High Threshold
V
IN
= 2.5 V to 6.5 V
V
IH
45
%V
IN
SHDN Input Low Threshold
V
IN
= 2.5 V to 6.5 V
V
IL
15
%V
IN
ERROR Output
Minimum V
IN
Operating Voltage
V
INMIN
1.0
V
Output Logic Low Voltage
1.0 mA Flows to ERROR
V
OL
400
mV
ERROR Threshold Voltage
See Figure 3
V
TH
0.95 x V
R
V
ERROR Positive Hysteresis
Note 9.
V
HYS
50
mV
(VOUTMAX
*
VOUTMIN)
106
VOUT
D
T
3. V
R
is the regulator output voltage setting. For example: V
R
= 2.5 V, 2.7 V, 2.85 V, 3.0 V, 3.3 V, 3.6 V, 4.0 V, 5.0 V.
4. T
C
V
OUT
=
5. Regulation is measured at a constant junction temperature using low duty cycle pulse testing. Load regulation is tested over a load range
from 0.1 mA to the maximum specified output current. Changes in output voltage due to heating effects are covered by the thermal
regulation specification.
6. Dropout voltage is defined as the input to output differential at which the output voltage drops 2% below its nominal value.
7. Thermal Regulation is defined as the change in output voltage at a time T after a change in power dissipation is applied, excluding load
or line regulation effects. Specifications are for a current pulse equal to I
LMAX
at V
IN
= 6.0 V for T = 10 msec.
8. The maximum allowable power dissipation is a function of ambient temperature, the maximum allowable junction temperature, and the
thermal resistance from junctiontoair (i.e. T
A
, T
J
,
q
JA
). Exceeding the maximum allowable power dissipation causes the device to initiate
thermal shutdown. Please see
Thermal Considerations section of this data sheet for more details.
9. Hysteresis voltage is referenced by V
R
.
10. Apply for Junction Temperatures of 40
C to +85
C.
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4
PIN DESCRIPTION
Pin
Number
Symbol
Description
1
V
IN
Unregulated supply input.
2
GND
Ground terminal.
3
SHDN
Shutdown control input. The regulator is fully enabled when a logic high is applied to this input. The
regulator enters shutdown when a logic low is applied to this input. During shutdown, output voltage
falls to zero, ERROR is open circuited and supply current is reduced to 0.5
A (max).
4
ERROR
OutofRegulation Flag. (Open drain output). This output goes low when V
OUT
is outoftolerance by
approximately 5.0%.
5
V
OUT
Regulated voltage output.
DETAILED DESCRIPTION
The NCP4555 and NCP4586 are precision fixed output
voltage regulators. Unlike bipolar regulators, the NCP4555
and NCP4586 supply current does not increase with load
current. In addition, V
OUT
remains stable and within
regulation at very low load currents (an important
consideration in RTC and CMOS RAM battery backup
applications).
Figure 2 shows a typical application circuit. The regulator
is enabled any time the shutdown input (SHDN) is at or
above V
IH
, and shutdown (disabled) when SHDN is at or
below V
IL
. SHDN may be controlled by a CMOS logic gate,
or I/O port of a microcontroller. If the SHDN input is not
required, it should be connected directly to the input supply.
While in shutdown, supply current decreases to 0.05
A
(typical), V
OUT
falls to zero volts, and ERROR is
opencircuited.
Figure 2. Typical Application Circuit
NCP4555
NCP4586
V
IN
GND
SHDN
BATTLOW
or RESET
V
OUT
ERROR
V
OUT
+
C1
1
F
R1
1 M
Shutdown Control
(to CMOS Logic or Tie
to V
IN
if unused)
+
1
F
+
C2
0.2
F
+
BATTERY
C2 Required Only
if ERROR is used as a
Processor RESET Signal
(See Text)
V
+
ERROR Open Drain Output
ERROR is driven low whenever V
OUT
falls out of
regulation by more than 5.0% (typical). This condition may
be caused by low input voltage, output current limiting, or
thermal limiting. The ERROR threshold is 5.0% below rated
V
OUT
regardless of the programmed output voltage value
(e.g. ERROR = V
OL
at 4.75 V (typ.) for a 5.0 V regulator and
2.85 V (typ.) for a 3.0 V regulator). ERROR output
operation is shown in Figure 3.
Note that ERROR is active when V
OUT
falls to V
TH
, and
inactive when V
OUT
rises above V
TH
by V
HYS
.
As shown in Figure 2, ERROR can be used as a battery
low flag, or as a processor RESET signal (with the addition
of timing capacitor C2). R1 x C2 should be chosen to
maintain ERROR below V
IH
of the processor RESET input
for at least 200 msec to allow time for the system to stabilize.
Pullup resistor R1 can be tied to V
OUT
, V
IN
or any other
voltage less than (V
IN
+ 0.3 V).
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5
HYSTERESIS (V
HYS
)
ERROR
V
OUT
V
TH
V
IH
V
OL
Figure 3. ERROR Output Operation
Output Capacitor
A 1.0
F (min) capacitor from V
OUT
to ground is
recommended. The output capacitor should have an
effective series resistance of 5.0
or less, and a resonant
frequency above 1.0 MHz. A 1.0
F capacitor should be
connected from V
IN
to GND if there is more than 10 inches
of wire between the regulator and the AC filter capacitor, or
if a battery is used as the power source. Aluminum
electrolytic or tantalum capacitor types can be used. (Since
many aluminum electrolytic capacitors freeze at
approximately 30
C, solid tantalums are recommended for
applications operating below 25
C.) When operating from
sources other than batteries, supplynoise rejection and
transient response can be improved by increasing the value
of the input and output capacitors and employing passive
filtering techniques.
Thermal Considerations
Thermal Shutdown
Integrated thermal protection circuitry shuts the regulator
off when die temperature exceeds 160
C. The regulator
remains off until the die temperature drops to approximately
150
C.
Power Dissipation
The amount of power the regulator dissipates is primarily
a function of input and output voltage, and output current.
The following equation is used to calculate worst case actual
power dissipation:
PD
[
(VINMAX
*
VOUTMIN)ILOADMAX
PD
+
worst case actual power dissipation
Where :
VINMAX
+
maximum voltage on VIN
VOUTMIN
+
minimum regulator output voltage
ILOADMAX
+
maximum output (load) current
(eq. 1)
The maximum allowable power dissipation (Equation 2)
is a function of the maximum ambient temperature
(T
AMAX
), the maximum allowable die temperature (125
C),
and the thermal resistance from junctiontoair (
q
JA
). The
5Pin SOT23 package has a
q
JA
of approximately
200
5C/Watt when mounted on a single layer FR4 dielectric
copper clad PC board.
PDMAX
+
(TJMAX
*
TAMAX)
q
JA
Where all terms are previously defined.
(eq. 2)
Equation 1 can be used in conjunction with Equation 2 to
ensure regulator thermal operation is within limits. For
example:
VINMAX
+
3.0 V
"
5.0%
GIVEN :
VOUTMIN
+
2.7 V
*
2.5%
ILOAD
+
40 mA
TAMAX
+
55
C
FIND :
1. Actual power dissipation.
2. Maximum allowable dissipation.
PD
[
(VINMAX
*
VOUTMIN)ILOADMAX
Actual power dissipation :
+
[(3.0
1.05)
*
(2.7
.975)] 40
10
*
3
+
20.7 mW
PDMAX
+
(TJMAX
*
TAMAX)
q
JA
Maximum allowable power dissipation :
+
(125
*
55)
+
318 mW
220
In this example, the NCP4555 dissipates a maximum of
only 20.7 mW; far below the allowable limit of 318 mW. In
a similar manner, Equation 1 and Equation 2 can be used to
calculate maximum current and/or input voltage limits.
Layout Considerations
The primary path of heat conduction out of the package is
via the package leads. Therefore, layouts having a ground
plane, wide traces at the pads, and wide power supply bus
lines combine to lower
q
JA
and, therefore, increase the
maximum allowable power dissipation limit.
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