Datasheet

11
LT1020
sn1020 1020fcs
+
10µF
0.001µF
1M
50k
2
11
9
V
OUT
FB
GND
LT1020
1020 TA13
INTERNAL PARASITIC
DIODES OF LT1020
GND
LT1020
1M
11
2
V
OUT
5V
9
3
V
IN
BATTERY
INPUT
V
IN
3
MAIN
POWER
INPUT
FB
V
OUT
V
IN
V
OUT
Battery Backup Regulator
5V Regulator with Shutdown
1020 TA15
5
6
1M
R2
1M
V
OUT
0.001µF
+
4
7
8
9
1M
10µF
2
11
FB
V
IN
3
REF
LT1020
0.047µF
1M
13
DROP-
OUT
V
OUT
*
R1
1.5M
–
+
1.5M
V
OUT
TURNS OFF AT DROPOUT.
V
OUT
TURN ON WHEN:
V
IN
× R2
R1 + R2
= 2.5V
*
Turn-Off at Dropout
+
NC
10µF
0.001µF
1M
1M
5V
2
11
3
9
V
IN
V
OUT
FB
GND
LT1020
1020 TA14
TRANSISTOR USED BECAUSE OF LOW LEAKAGE
CHARACTERISTICS. TO TURN OFF THE OUTPUT
OF THE LT1020, FORCE FB (PIN 11) > 2.5V
*
V
IN
> 5.2V
I
Q
= 40µA
100k
500k
2N3904*
LOGIC INPUT
TYPICAL APPLICATIO S
U
Current Limited 1 Amp Regulator
+
220µF
†
100k
2
11
3
9
V
IN
V
OUT
FB
GND
LT1020
1020 TA16
0.22µF
V
OUT
5V, 1A
2.2k
270Ω
100k
SETS CURRENT LIMIT BUT INCREASES
DROPOUT VOLTAGE BY 0.5V
MUST HAVE LOW ESR. SEVERAL 100µF
CAPACITORS CAN BE PARALLELED
*
†
MJE2955
0.5Ω*
V
IN
2N3906*