4
LT3028
3028f
TYPICAL PERFOR A CE CHARACTERISTICS
UW
Note 4: Operating conditions are limited by maximum junction
temperature. The regulated output voltage specification will not apply for
all possible combinations of input voltage and output current. When
operating at maximum input voltage, the output current range must be
limited. When operating at maximum output current, the input voltage
range must be limited.
Note 5: To satisfy requirements for minimum input voltage, the LT3028 is
tested and specified for these conditions with an external resistor divider
(two 250k resistors) for an output voltage of 2.44V. The external resistor
divider will add a 5µA DC load on the output.
Note 6: Dropout voltage is the minimum input to output voltage differential
needed to maintain regulation at a specified output current. In dropout, the
output voltage will be equal to: V
IN
– V
DROPOUT
.
Note 7: GND pin current is tested with V
IN
= 2.44V and a current source
load. This means the device is tested while operating in its dropout region
or at the minimum input voltage specification. This is the worst-case GND
pin current. The GND pin current will decrease slightly at higher input
voltages. Total GND pin current is equal to the sum of GND pin currents
from Output 1 and Output 2.
Note 8: ADJ1 and ADJ2 pin bias current flows into the pin.
Note 9: SHDN1 and SHDN2 pin current flows into the pin.
Note 10: For the LT3028 dropout voltage will be limited by the minimum
input voltage specification under some output voltage/load conditions. See
the curve of Minimum Input Voltage in the Typical Performance
Characteristics.
ELECTRICAL CHARACTERISTICS
Output 2
Typical Dropout Voltage
OUTPUT CURRENT (mA)
500
450
400
350
300
250
200
150
100
50
0
DROPOUT VOLTAGE (mV)
3028 G01
0 102030
40
50
60 70 80 90 100
T
J
= 125°C
T
J
= 25°C
Output 1
Typical Dropout Voltage
OUTPUT CURRENT (mA)
500
450
400
350
300
250
200
150
100
50
0
DROPOUT VOLTAGE (mV)
3028 G02
0 102030
40
50
60 70 80 90 100
T
J
≤ 125°C
T
J
≤ 25°C
= TEST POINTS
TEMPERATURE (°C)
–50
DROPOUT VOLTAGE (mV)
0
50
75
3028 G03
–25
25
100
125
I
L
= 100mA
I
L
= 50mA
I
L
= 10mA
I
L
= 1mA
500
450
400
350
300
250
200
150
100
50
0
Output 2
Guaranteed Dropout Voltage
Output 2 Dropout Voltage
Output 1
Guaranteed Dropout Voltage
Output 1 Dropout Voltage
OUTPUT CURRENT (mA)
500
450
400
350
300
250
200
150
100
50
0
DROPOUT VOLTAGE (mV)
3028 G04
0 50 100 150
200
250
300 350 400 450 500
T
J
= 125°C
T
J
= 25°C
OUTPUT CURRENT (mA)
500
450
400
350
300
250
200
150
100
50
0
GUARANTEED DROPOUT VOLTAGE (mV)
3028 G05
0 50 100 150
200
250
300 350 400 450 500
T
J
≤ 125°C
T
J
≤ 25°C
= TEST POINTS
TEMPERATURE (°C)
–50
DROPOUT VOLTAGE (mV)
0
50
75
3028 G06
–25
25
100
125
500
450
400
350
300
250
200
150
100
50
0
I
L
= 500mA
I
L
= 250mA
I
L
= 100mA
I
L
= 50mA
I
L
= 1mA
I
L
= 10mA
