LT1789-1/LT1789-10
21
1789fc
TYPICAL APPLICATIONS
Avalanche Photo Diode Module Bias Current Monitor
OUTPUT
0V TO 1V =
0mA TO 1mA
5V
+
–
5V
A1
LT1789-1
–3.5V
0.2μF
S1
0.2μF
V
OUT
= 20V TO 90V
TO APD
FOR OPTIONAL “ZERO CURRENT” FEEDBACK TO
APD BIAS REGULATOR, SEE APPENDIX A, APPLICATION NOTE 92
APD
HIGH VOLTAGE
BIAS INPUT
1789 TA05
1k*
1%
100k*
–
+
5V
A2
LT1006
–3.5V
100k*
Q1
1M*
1M*
Q2
MPSA42
5V
S3
S2
20k
15
16 17 4
3
18
5
2
6
12
13 14
22μF
22μF
–3.5V TO
AMPLIFIERS
0.056μF
5V
20k*
20k
200k*
1μF
1μF
1μF
100V
1μF
100V
30k
10k
1N4690
5.6V
#
= 1N4148
= 0.1% METAL FILM RESISTOR
= TECATE CMC100105MX1825
= LTC1043 PIN NUMBER
= TP0610L
*
1μF 100V
CIRCLED NUMBERS
+
+
†
FOR MORE INFORMATION REFER TO APPLICATION NOTE 92
Single Supply Positive Integrator
+
3
V
IN
V
OUT
8
1
2
3
2
4
5
6
R1
10k
C1
100μF
R2
10Ω
RESET
1789 TA02
V
S
= 2.7V TO 32V
TIME CONSTANT = (R1)(C1) = 1 SECOND AS SHOWN
7
V
S
–
+
1
4
V
S
LT1636
–
+
LT1789-1
REF