Datasheet

Data Sheet AD737
Rev. I | Page 17 of 24
+
R
CAL
**
R1**
I
REF
10
*
11
9
Q2
**R1 + R
CAL
IN Ω = 10,000 ×
4.3V
0dB INPUT LEVEL IN V
AD711
1kΩ
3500PPM/°C
60.4Ω
dB OUTPUT
100mV/dB
PRECISION
RESISTOR
CORP
TYPE PT/ST
2kΩ
31.6kΩ
SCALE
FACTOR
TRIM
13
Q1
12
14
*
RMS
CORE
AD737
BIAS
SECTION
INPUT
AMPLIFIER
8kΩ
8kΩ
1
2
3
4
8
7
6
5
3
6
2
V
IN
POWER
DOWN
–V
S
C
C
COM
OUTPUT
+V
S
NC
C
AV
C
AV
+
00828-030
C
C
10µF
NC = NO CONNECT
*Q1, Q2 PART OF RCA CA3046 OR SIMILAR NPN TRANSISTOR ARRAY.
FULL-WAVE
RECTIFIER
Figure 30. dB Output Connection
COM
1
2
3
8
7
6
V
OUT
+V
S
–V
S
+V
S
C
C
V
IN
POWER
DOWN
AD737
INPUT
AMPLIFIER
OFFSETADJUST
500kΩ
8kΩ
00828-031
SCALE
FACTOR
ADJUST
1kΩ
1MΩ
1kΩ
499Ω
FULL-WAVE
RECTIFIER
Figure 31. DC-Coupled Offset Voltage and Scale Factor Trims