lt1763cs8-trpbf Linear Technology Corporation, lt1763cs8-trpbf Datasheet - Page 17

• Manufacturer Part Number: lt1763cs8-trpbf
• Description: 500ma, Low Noise, Ldo Micropower Regulators
• Manufacturer: Linear Technology Corporation

APPLICATIONS
The top resistor of the resistor divider must be chosen
to limit the current into the ADJ pin to less than 5mA
when the ADJ pin is at 7V. The 13V difference between
output and ADJ pin divided by the 5mA maximum
current into the ADJ pin yields a minimum top resistor
value of 2.6k.
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
U
INFORMATION
U
W
100
90
80
70
60
50
40
30
20
10
0
Figure 7. Reverse Output Current
0
T
V
CURRENT FLOWS
INTO OUTPUT PIN
V
U
J
IN
OUT
LT1763-2.5
LT1763-3
= 25°C
1
= 0V
LT1763-1.8
= V
2
ADJ
OUTPUT VOLTAGE (V)
3
(LT1763)
LT1763
4
5
circuit. Current flow back into the output will follow the
curve shown in Figure 7.
When the IN pin of the LT1763-X is forced below the OUT
pin or the OUT pin is pulled above the IN pin, input current
will typically drop to less than 2µA. 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 SHDN pin will have no effect on the reverse output
current when the output is pulled above the input.
LT1763-3.3
6
7
LT1763-1.5
LT1763-5
8
9
1763 F07
10
LT1763 Series
17
1763fc