LT1020_03 Datasheet, PDF (13/16 Pages) Linear Technology – Micropower Regulator and Comparator

TYPICAL APPLICATIO S
1M
51k
0.0033µF
8_–
7₊
51k
Charge Pump Voltage Doubler
V_IN
1N5819
OR EQUIVALENT
V_OUT
+
3
20µF
5
6
9
1M
2N3904
22k
10µF
1020 TA20
V_OUT (NL) ≅ 2V_IN – 1V
V_OUT (5mA) ≅ 2V_IN – 3V
I_Q ≅ 300µA
LT1020
50mA Battery Charger and Regulator
+
+
V_IN*
10µF
10µF 51k
2N2905
10µF
20k
220k
8
43
V_IN
2
V_OUT
5V
6
LT1020
7
*V_IN MUST BE GREATER THAN THE
BATTERY VOLTAGE PLUS 1.3V
2.5V
1M
11
FB
1M
9
0.001µF
10µF
6V
BATTERY
3.9Ω
1020 TA21
V_IN
TO
V_REF
(PIN4)
7.5V TO 30V
100µF
1.8M
1M
Switching Preregulator for Wide Input Voltage Range
3.3M
2N3904
2N3904
1k
30k
2N3906
10k
100k
LT1020
COMPARATOR
2N2222
2M
8
SWITCHING
REGULATOR
OUTPUT
4mH
30k
POST REGULATOR
3 _VIN
2
LT1020 ^VOUT
V_REF
4
FB
11
V_OUT
5V
100mA
22µF
6
MAINTAINS LOW I_Q (< 100µA)
FOR ALL INPUT VOLTAGES
SWITCHER EFFICIENCY = 85%
POST REGULATOR EFFICIENCY = 82%
2M
OVERALL EFFICIENCY = 70%
SWITCHING REGULATOR OUTPUT =
2.5 × (1 + R_A/R_B). FOR A CLEAN OUTPUT
FROM THE LINEAR REGULATOR SET TO V_OUT + 1.2V
R_A
7
1.5M
R_B
1M
0.001µF
30k
100µF
0.01µF 220k
220k
1020 TA22
sn1020 1020fcs
13