Datasheet

6
LT1020
sn1020 1020fcs
Pins 1, 14: No Internal Connection.
Pin 2: Regulator Output. Main output, requires 10µF
output capacitor. Can be shorted to V
IN
or ground without
damaging the device.
Pin 3: Input Supply. Bypass with 10µF capacitor. Must
always be more positive than ground.
Pin 4: Reference. 2.5V can source or sink current. May be
shorted to ground or up to 5V. Voltages in excess of 5V can
damage the device.
Pin 5: Comparator PNP Output. Open Collector PNP
Output. Pull-up current source for the comparator. May be
connected to any voltage from V
IN
to 36V more negative
than V
IN
(operates below ground). Short-circuit protected.
For example, if V
IN
is 6V then pin 5 will operate to –30V.
Pin 6: Comparator NPN Output. Open Collector NPN
Output. May be connected to any voltage from ground to
36V more positive than ground (operates above V
IN
).
Short-circuit protected.
Pins 7, 8: Comparator Inputs. Operates from ground to
V
IN
– 1V. Comparator inputs will withstand 36V even with
V
IN
of 0V.
Pin 9: Ground.
Pin 10: Current Limit. Connecting this pin to ground
decreases the regulator current limit to 3mA minimum.
Leave open when not used.
Pin 11: Feedback. This is the feedback point of the regu-
lator. When operating, it is nominally at 2.5V. Optimum
source resistance is 200k to 500k. The feedback pin
should not be driven below ground or more positive than
5V.
Pin 12: Shutdown. Turns output off.
Pin 13: Dropout Detector. This pin acts like a current
source from V
IN
which turns on when the output transistor
goes into saturation. The magnitude of the current de-
pends on the magnitude of the output current and the
input/output voltage differential. Pin current ranges from
5µA to about 300µA.
INPUT VOLTAGE (V)
1
OUTPUT VOLTAGE (V)
0
1020 G17
3
5
7
5.5
5.0
4.5
4.0
3.5
3.0
2.5
2.0
0
24
6
8
R
L
= 500Ω
R
L
= 50ΩNO LOAD
V
OUT
= 5V
Regulator Thermal Regulation
TIME (ms)
0
OUTPUT
CURRENT (mA)
0.1
140
1020 G16
20
40
80
180
V
IN
= 15V
V
OUT
= 5V
60
0
–0.1
0
50
OUTPUT VOLTAGE
CHANGE (%)
100
120 160
LT1020 Turn-On Characteristic
TYPICAL PERFOR A CE CHARACTERISTICS
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PI FU CTIO S