Texas Instruments UCC381DPTR-ADJ, UCC381DPTR-5, UCC381DP-ADJ, UCC381DP-5, UCC381DP-3 Datasheet
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Low Dropout 1 Ampere Linear Regulator Family
UCC281-3/-5/-ADJ
UCC381-3/-5/-ADJ
FEATURES
Precision Positive Linear Voltage
•
Regulation
0.5V Dropout at 1A
•
Guaranteed Reverse Input/ Output
•
Voltage Isolation with Low Leakage
Low Quiescent Current Irrespective of
•
Load
Adjustable Output Voltage Version
•
Fixed Versions for 3.3V and 5V
•
Outputs
Logic Shutdown Capability
•
Short Circuit Power Limit of
•
3% • V
• Remote Load Voltage for Accurate
Load Regulation
• Current Limit
IN
DESCRIPTION
The UCC381-3/-5/-ADJ family of positive linear series pass regulators is
tailored for low drop out applications where low quiescent power is impor
tant. Fabricated with a BiCMOS technology ideally suited for low input to
output differential applications, the UCC381 will pass 1A while requiring
only 0.5V of input voltage headroom. Dropout voltage decreases linearly
with output current, so that dropout at 200mA is less than 100mV. Quies
cent current is always less than 650µA. To prevent reverse current conduc
tion, on-chip circuitry limits the minimum forward voltage to typically 50mV.
Once the forward voltage limit is reached, the input-output differential volt
age is maintained as the input voltage drops until undervoltage lockout dis
ables the regulator.
UCC381-3 and UCC381-5 versions have on-chip resistor networks preset
to regulate either 3.3V or 5.0V, respectively. Furthermore, remote sensing
of the load voltage is possible by connecting the VOUTS pin directly at the
load. The output voltage is then regulated to 1.5% at room temperature and
better than 2.5% over temperature. The UCC381-ADJ version has a regu
lated output voltage programmed by an external user-definable resistor ratio.
(continued)
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-
-
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BLOCK DIAGRAM
8
VIN
SHUTDOWN FOR FIXED VERSIONS
5
CT*
*ADJ
VERSION
ONLY
1.3/2.1A
CURRENT
REFERENCE
0.65V
3% DUTY CYCLE
CURRENT LIMIT TIMER
REVERSE VOLTAGE
SENSE
CURRENT
LIMIT
–
+
THERMAL
SHUTDOWN
V
PUMP
UVLO
VOLTAGE
AMPLIFIER
–
+
UCC381-ADJ
UCC381-3
UCC381-5
R2
1.25V
R1
R2 R1
0 OPEN
82k 50k
150k 50k
1VOUT
VOUTS
4
2GND
3GND
6
GND
GND
7
SLUS214A - NOVEMBER 1999
UDG-98112
UCC281-3/-5/-ADJ
UCC381-3/-5/-ADJ
ABSOLUTE MAXIMUM RATINGS
VIN. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9V
CT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −0.3 to 3V
Storage Temperature . . . . . . . . . . . . . . . . . . . −65°C to +150°C
Junction Temperature. . . . . . . . . . . . . . . . . . . −55°C to +150°C
Lead Temperature (Soldering, 10 sec.) . . . . . . . . . . . . . +300°C
Currents are positive into, negative out of the specified terminal.
Consult Packaging Section of Databook for thermal limitations
and considerations of packages. All voltages are referenced to
GND.
DESCRIPTION (cont.)
Short circuit current is internally limited. The device re
sponds to a sustained overcurrent condition by turning
off after a T
riod, T
OFF
then begins pulsing on and off at the T
duty cycle of 3%. This drastically reduces the power dissipation during short circuit such that heat sinking, if at all
required, must only accommodate normal operation. On
the fixed output versions of the device T
400µs − a guaranteed minimum. On the adjustable version an external capacitor sets the on time. The off time
is always 32 times T
delay. The device then stays off for a pe
ON
, that is 32 times the TONdelay. The device
/(TON+T
ON
ON
ON is fixed at
.
OFF
CONNECTION DIAGRAMS
SOIC-8 (Top View)
DP Package
VOUT
VOUTS
GND
GND
1
2
3
4
* ADJ version only
-
The UCC381 can be shutdown to 25µA (max) by pulling
the CT pin low.
Internal power dissipation is further controlled with ther
mal overload protection circuitry. Thermal shutdown oc
)
curs if the junction temperature exceeds 165°C. The chip
will remain off until the temperature has dropped 20°C.
The UCC281 series is specified for operation over the industrial range of −40°Cto+85°C, and the UCC381 se-
ries is specified from 0°Cto+70°C. These devices are
available in the 8 pin DP surface mount power package.
For other packaging options consult the factory.
VIN
8
GND
7
GND
6
CT*
5
-
-
ELECTRICAL CHARACTERISTICS: Unless otherwise stated, these specifications hold for TA = 0°C to 70°C for the
UCC381-X series and −40°C to +85°C for the UCC283-X series, V
the UCC381-ADJ version and V
set to 5V. TJ= TA.
OUT
IN=VOUT
PARAMETER TEST CONDITIONS MIN TYP MAX UNITS
UCC381-5 Fixed 5V, 1A Family
Output Voltage T
= 25°C 4.925 5 5.075 V
J
Over Temperature 4.875 5.125 V
Line Regulation V
Load Regulation I
Drop Out Voltage, V
IN–VOUT
Peak Current Limit V
= 5.15V to 9V 1 3 mV
IN
= 0mA to 1A 2 5 mV
OUT
I
= 1A, V
OUT
= 200mA, V
I
OUT
= 0V 2 3.5 A
OUT
= 4.85V, TA < 85°C 0.5 0.6 V
OUT
OUT
Overcurrent Threshold 1 1.8 A
Current Limit Duty Cycle V
Overcurrent Time Out, T
ON
= 0V 3 5 %
OUT
V
= 0V 400 750 1600 µs
OUT
Quiescent Current 400 650 µA
Quiescent Current in Shutdown V
Shutdown Threshold At C
Reverse Leakage Current 1V < V
UVLO Threshold V
= 9V 10 25 µA
IN
Input 0.25 0.65 V
T
IN<VOUT,VOUT
where V
IN
passes current 2.5 2.8 3.0 V
OUT
+ 1.5V, I
OUT
= 0mA, C
= 2.2µF. CT= 1500pF for
OUT
= 4.85V, TA < 85°C 100 200 mV
< 5.1V, at VOUT 75 µA
2
UCC281-3/-5/-ADJ
UCC381-3/-5/-ADJ
ELECTRICAL CHARACTERISTICS:
UCC381-X series and −40°C to +85°C for the UCC283-X series, V
the UCC381-ADJ version and V
set to 5V. TJ= TA.
OUT
Unless otherwise stated, these specifications hold for TA = 0°C to 70°C for the
IN=VOUT
+ 1.5V, I
OUT
= 0mA, C
= 2.2µF. CT= 1500pF for
OUT
PARAMETER TEST CONDITIONS MIN TYP MAX UNITS
UCC381-3 Fixed 3.3V, 1A Family
Output Voltage T
= 25°C 3.25 3.3 3.35 V
J
Over Temperature 3.22 3.38 V
Line Regulation V
Load Regulation I
Dropout Voltage, V
IN-VOUT
Peak Current Limit V
= 3.45V to 9V 1 3 mV
IN
= 0mA to 1A 2 5 mV
OUT
I
= 1A, V
OUT
= 200mA, V
I
OUT
= 0V 2 3.5 A
OUT
= 3.15V, TA < 85°C 0.6 0.8 V
OUT
= 3.15V, TA< 85°C 100 200 mV
OUT
Overcurrent Threshold 1 1.8 A
Current Limit Duty Cycle V
Overcurrent Time Out, T
ON
= 0V 3 5 %
OUT
V
= 0V 400 750 1600 µs
OUT
Quiescent Current 400 650 µA
Quiescent Current in Shutdown V
Shutdown Threshold At C
Reverse Leakage Current 1V < V
UVLO Threshold V
= 9V 10 25 µA
IN
Input 0.25 0.65 V
T
IN<VOUT,VOUT
where V
IN
OUT
< 3.35V, at VOUT 75 µA
passes current 2.5 2.8 3.0 V
UCC381-ADJ Adjustable Output, 1A Family
Regulating Voltage at ADJ Input T
= 25°C 1.23 1.25 1.27 V
J
Over Temperature 1.22 1.28 V
Line Regulation, at ADJ Input V
Load Regulation, at ADJ Input I
Dropout Voltage, V
IN-VOUT
Peak Current Limit V
IN=VOUT
OUT
I
OUT
I
OUT
OUT
+ 150mV to 9V 1 3 mV
= 0mA to 1A 2 5 mV
= 1A, V
= 200mA, V
= 4.85V 0.5 0.6 V
OUT
= 4.85V 100 200 mV
OUT
= 0V 2 3.5 A
Overcurrent Threshold 1 1.8 A
Current Limit Duty Cycle V
Overcurrent Time Out, T
ON
= 0V 3 5 %
OUT
V
= 0V, CT= 1500pF 400 1000 1600 µs
OUT
Quiescent Current 400 650 µA
Quiescent Current in Shutdown V
Shutdown Threshold At C
Reverse Leakage Current 1V < V
= 9V 10 25 µA
IN
Input 0.25 0.65 V
T
IN<VOUT,VOUT
< 9V, at V
OUT
100 µA
Bias Current at ADJ Input 100 250 nA
UVLO Threshold V
where V
IN
passes current 2.5 2.8 3.0 V
OUT
3
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