LT3023 LINER [Linear Technology], LT3023 Datasheet - Page 13

• Manufacturer Part Number: LT3023
• Description: Dual 100mA, Low Dropout, Low Noise, Micropower Regulator
• Manufacturer: LINER [Linear Technology]

3.7V TO 20V
APPLICATIO S I FOR ATIO
In circuits where a backup battery is required, several
different input/output conditions can occur. The output
voltage may be held up while the input is either pulled to
ground, pulled to some intermediate voltage or is left open
circuit. Current flow back into the output will follow the
curve shown in Figure 6.
When the IN pin of the LT3023 is forced below the OUT1
or OUT2 pins or the OUT1/OUT2 pins are pulled above the
IN pin, input current will typically drop to less than 2 A.
This can happen if the input of the device is connected to
a discharged (low voltage) battery and the output is held
up by either a backup battery or a second regulator circuit.
The state of the SHDN1/SHDN2 pins will have no effect on
the reverse output current when the output is pulled above
the input.
TYPICAL APPLICATIO S
V
IN
OFF ON
1 F
IN
SHDN1
SHDN2
U
LT3023
GND
U
OUT1
BYP1
OUT2
BYP2
ADJ1
ADJ2
U
Noise Bypassing Slows Startup, Allows Outputs to Track
W
0.01 F
0.01 F
422k
249k
261k
249k
U
10 F
10 F
3.3V
AT 100mA
2.5V
AT 100mA
3023 TA02a
V
SHDN1/SHDN2
100
760
90
80
60
50
40
30
20
10
Figure 6. Reverse Output Current
1V/DIV
1V/DIV
1V/DIV
0
V
V
0
OUT1
OUT2
T
V
V
CURRENT FLOWS
INTO OUTPUT PIN
100
0.1
A
IN
OUT
10
1
= 25 C
1
= 0V
10
= V
2
ADJ
OUTPUT VOLTAGE (V)
3
4
100
Startup Time
5
2ms/DIV
C
BYP
6
(pF)
7
1000
8
3023 F06
9
3023 TA02b
10
3023 TA02c
LT3023
10000
13
3023f