UCC283-3_12 Datasheet, PDF (1/22 Pages) Texas Instruments – LOW-DROPOUT 3-A LINEAR REGULATOR FAMILY

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UCC283-3, UCC283-5, UCC283-ADJ, UCC383-3, UCC383-5, UCC383-ADJ
LOWĆDROPOUT 3ĆA LINEAR REGULATOR FAMILY
SLUS215B − OCTOBER 1998 − REVISED FEBRUARY 2004
D Precision Positive Linear Series Pass
Voltage Regulation
D 0.45 V Dropout at 3 A
D 50 mV Dropout at 10 mA
D Quiescent Current Under 650 µA
Irrespective of Load
D Adjustable (5-Lead) Output Voltage Version
D Fixed (3-Lead) Versions for 3.3-V and 5-V
Outputs
D Logic Shutdown Capability
D Short-Circuit Power Limit of
(3% × V_IN × I_SHORT)
D Low V_OUT to V_IN Reverse Leakage
D Thermal Shutdown
description
The UCC283−3/−5/−ADJ family of positive linear
series pass voltage regulators are tailored for
low-drop-out applications where low quiescent
power is important. Fabricated with a BiCMOS
technology ideally suited for low input-to-output
differential applications, the UCC283−5 passes
3 A while requiring only 0.45 V of typical input
voltage headroom (ensured 0.6-V dropout).
TO−263−5 TD PACKAGE
(FRONT VIEW)
5
VOUT
4
ADJ
3
GND
2
CT
1
VIN
TO−263−3 TD PACKAGE
(FRONT VIEW)
3
VOUT
2
GND
1
VIN
TO−220−5 T PACKAGE
(FRONT VIEW)
5
4
+
3
2
1
VOUT
ADJ
GND
CT
VIN
TO−220−3 T PACKAGE
(FRONT VIEW)
3
+
2
1
VOUT
GND
VIN
These regulators include reverse voltage sensing that prevents current in the reverse direction. Quiescent
current is always less than 650 µA. These devices have been internally compensated in such a way that the
need for a minimum output capacitor has been eliminated.
UCC283−3 and UCC283−5 versions are in 3-lead packages and have preset outputs at 3.3 V and 5.0 V
respectively. The output voltage is regulated to 1.5% at room temperature. The UCC283−ADJ version, in a
5-lead package, regulates the output voltage programmed by an external resistor ratio.
Short-circuit current is internally limited. The device responds to a sustained overcurrent condition by turning
off after a t_ON time delay. The device then stays off for a period, t_OFF, that is 32 times the t_ON delay. The device
then begins pulsing on and off at the t_ON/(t_ON+t_OFF) duty cycle of 3%. This drastically reduces the power
dissipation during short-circuit and means heat sinks need only accommodate normal operation. On the
3-leaded versions of the device t_ON is fixed at 750 µs, on the adjustable 5-leaded versions an external capacitor
sets the on time. The off time is always 32 × t_ON. The external timing control pin, CT, on the 5-leaded versions
also serves as a shutdown input when pulled low.
Internal power dissipation is further controlled with thermal overload protection circuitry. Thermal shutdown
occurs if the junction temperature exceeds 165°C. The chip remains off until the temperature has dropped 20°C.
The UCC283 series is specified for operation over the industrial range of −40°C to 85°C, and the UCC383 series
is specified from 0°C to 70°C. These devices are available in 3- and 5-pin TO−220 and TO−263 power packages.
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PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
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