LT1083/84/85 Fixed
3A, 5A, 7.5A Low Dropout
Positive Fixed Regulators
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FEATURES
DESCRIPTION
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Three-Terminal 3.3V, 3.6V, 5V and 12V
Output Current of 3A, 5A or 7.5A
Operates Down to 1V Dropout
The LT1083 series of positive adjustable regulators are
designedtoprovide3A, 5Aand7.5Awithhigherefficiency
than currently available devices. All internal circuitry is
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Guaranteed Dropout Voltage at Multiple Current Levels designedtooperatedownto1Vinputtooutputdifferential
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Line Regulation: 0.015%
and the dropout voltage is fully specified as a function of
load current. Dropout is guaranteed at a maximum of 1.5V
at maximum output current, decreasing at lower load
currents. On-chip trimming adjusts the output voltage to
1%. Current limit is also trimmed, minimizing the stress
on both the regulator and power source circuitry under
overload conditions.
Load Regulation: 0.1%
100% Thermal Limit Functional Test
Adjustable Versions Available
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APPLICATIONS
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High Efficiency Linear Regulators
The 1083 series devices are pin compatible with older
three-terminal regulators. A 10µF output capacitor is
required on these new devices; however, this is usually
included in most regulator designs.
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Post Regulators for Switching Supplies
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Constant Current Regulators
Battery Chargers
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DEVICE
OUTPUT CURRENT*
Unlike PNP regulators, where up to 10% of the output
current is wasted as quiescent current, the LT1083 quies-
cent current flows into the load, increasing efficiency.
LT1083
LT1084
LT1085
7.5 Amps
5.0 Amps
3.0 Amps
*For a 1.5A low dropout regulator see the LT1086 data sheet.
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TYPICAL APPLICATION
5V, 7.5A Regulator
Dropout Voltage vs Output Current
2
V
IN
≥ 6.5V
5V AT 7.5A
LT1083-5
+
+
22µF*
TANTALUM
10µF
1
0
*REQUIRED FOR STABILITY
LT1083/4/5 TA01
0
I
/2
I
FULL LOAD
FULL LOAD
OUTPUT CURRENT (A)
1083/4/5 TA02
1