ad737ar Analog Devices, Inc., ad737ar Datasheet - Page 17

• Manufacturer Part Number: ad737ar
• Description: Low Cost, Low Power, True Rms-to-dc Converter
• Manufacturer: Analog Devices, Inc.

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