LT1962 Series
W U U
APPLICATIO S I FOR ATIO
U
fromthe1.22Vreferencewhentheoutputisforcedto20V.
The top resistor of the resistor divider must be chosen to
limitthecurrentintotheADJpintolessthan5mAwhenthe
ADJpinisat7V. The13VdifferencebetweenOUTandADJ
pin divided by the 5mA maximum current into the ADJ pin
yields a minimum top resistor value of 2.6k.
orasecondregulatorcircuit.ThestateoftheSHDNpinwill
have no effect on the reverse output current when the
output is pulled above the input.
100
T
= 25°C
IN
LT1962
J
V
90
80
70
60
50
= 0V
CURRENT FLOWS
INTO OUTPUT PIN
V
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, pulledtosomeintermediatevoltageorisleftopen
circuit. Current flow back into the output will follow the
curve shown in Figure 7.
= V
(LT1962)
OUT
ADJ
LT1962-1.5
LT1962-1.8
LT1962-2.5
40
30
LT1962-3
LT1962-3.3
20
10
0
LT1962-5
When the IN pin of the LT1962 is forced below the OUT pin
or the OUT pin is pulled above the IN pin, input current will
typicallydroptolessthan2µA. Thiscanhappeniftheinput
of the device is connected to a discharged (low voltage)
battery and the output is held up by either a backup battery
0
1
2
3
4
5
6
7
8
9
10
OUTPUT VOLTAGE (V)
1962 F07
Figure 7. Reverse Output Current
U
PACKAGE DESCRIPTIO
Dimensions in inches (millimeters) unless otherwise noted.
MS8 Package
8-Lead Plastic MSOP
(LTC DWG # 05-08-1660)
0.118 ± 0.004*
(3.00 ± 0.102)
8
7
6
5
0.118 ± 0.004**
(3.00 ± 0.102)
0.193 ± 0.006
(4.90 ± 0.15)
1
2
3
4
0.043
(1.10)
MAX
0.034
(0.86)
REF
0.007
(0.18)
0° – 6° TYP
SEATING
PLANE
0.009 – 0.015
(0.22 – 0.38)
0.021 ± 0.006
(0.53 ± 0.015)
0.005 ± 0.002
(0.13 ± 0.05)
0.0256
(0.65)
BSC
MSOP (MS8) 1100
* DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS. MOLD FLASH,
PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE
** DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS.
INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen-
tationthattheinterconnectionofitscircuitsasdescribedhereinwillnotinfringeonexistingpatentrights.
15
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