Parameter Test Conditions Min. Typ. Max. Unit
LT1085LCC4
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VREF Reference Voltage
REG(LINE) Line Regulation
REG(LOAD) Load Regulation
See notes 1,2
VDDropout Voltage
See note 3
ICL Current Limit
IQQuiescent Current
Minimum Load Current 4
REG(THERM) Thermal Regulation
RARipple Rejection
IPIN Adjust Pin Current
∆IPIN Adjust Pin Current Change
TSTemperature Stability
Long Term Stability
VNRMS Output Noise
VIN – VOUT = 3V IO= 10mA
VIN – VOUT = 1.5 to 15V IO= 10mA to 3A
TJ= –55 to 125°C
IO= 10mA (VIN–VOUT) = 1.5 to 15V
TJ= –55 to 125°C
IO= 10mA (VIN–VOUT) = 15 to 30V
TJ= –55 to 125°C
VIN – VOUT = 3V
IO= 10mA to 3A TJ= –55 to 125°C
∆VREF = 1%
IOUT = 3A TJ= –55 to 125°C
VIN – VOUT = 5V TJ= –55 to 125°C
VIN – VOUT = 25V TJ= –55 to 125°C
VIN – VOUT = 5V TJ= –55 to 125°C
TP= 30ms TA= 25°C
f = 120Hz VIN – VOUT = 3V
IO= 3A CADJ = 25µF
TJ= –55 to 125°C
VIN – VOUT = 1.5 to 15V
IO= 10mA to 3A TJ= –55 to 125°C
TJ= –55 to 125°C
TA= 125°C T = 1000 Hrs
f = 10Hz to 10kHz TA= 25°C
1.238 1.250 1.252
1.225 1.25 1.270
0.015 0.2
0.5
0.1 0.3
0.2 0.4
1.3 1.5
3.2 4
0.2 0.5
510
0.004 0.04
60 75
55 120
0.2 5
0.5
0.3
0.003
ELECTRICAL CHARACTERISTICS (Pre Irradiation) (TJ= 25°C unless otherwise stated)
V
%
%
V
A
mA
%/W
dB
µA
µA
%
%
%
DESCRIPTION
The LT1085 is designed to provide 3A with higher efficiency than currently available devices. All internal circuitry is
designed to operate down to 1V input to output differential 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 reference output voltage to 1%. Current limit is also trimmed, minimising the stress on both the
regulator and power source circuitry under overload conditions.
Notes:
1 Load and line regulation are measured at a constant junction temperature by low duty cycle pulse testing.
2 Power dissipation is determined by the input - output differential and the output current. Guaranteed maximum power
2dissipation will not be available over the full input - output voltage range.
3 Dropout voltage is specified over the full output current range of the device.
Document Number 3871
Issue 2
Semelab Plc reserves the right to change test conditions, parameter limits and package dimensions without notice. Information furnished by Semelab is
believed to be both accurate and reliable at the time of going to press. However Semelab assumes no responsibility for any errors or omissions discovered in
its use. Semelab encourages customers to verify that datasheets are current before placing orders.