AD652BQ/+ Analog Devices Inc, AD652BQ/+ Datasheet - Page 21

• Manufacturer Part Number: AD652BQ/+
• Description: IC V-F CONV SYNCH MONO 5V 16CDIP
• Manufacturer: Analog Devices Inc
• Type: Voltage to Frequencyr

Specifications of AD652BQ/+

• Rohs Status: RoHS non-compliant
• Frequency - Max: 2MHz
• Full Scale: ±25ppm/°C
• Linearity: ±0.005%
• Mounting Type: Through Hole
• Package / Case: 16-CDIP (0.300", 7.62mm)

Analog Signal Reconstruction
If it is desired to reconstruct the analog voltages from the
multiplex signal, three more AD652 SVFC devices are used as
frequency-to-voltage converters, as shown in Figure 31. The
comparator inputs of all the devices are strapped together, the
“+” inputs are held at a 1.2 V TTL threshold, and the “−” inputs
are driven by the multiplex input. The three clock inputs are
10kΩ
AD589
1.2V
V
V
IN
VOLTS
LO
OUT
+5V
HI
V
2
6.8kΩ
0.02µF
1.5kΩ
1.2kΩ
–V
+V
S
S
1
2
3
4
5
6
7
8
7915
10kΩ
1
2
3
4
SYNCHRONOUS
VOLTAGE-TO-
FREQUENCY
CONVERTER
AD652
–15V
–15V
REG
DRIVER
OSC
AD654
1N4148
7
47µF
47µF
φ
2,
6
φ
Figure 31. Demultiplexer Frequency-to-Voltage Conversion
16
15
14
13
12
11
10
3,
9
5
1N4148
φ
47µF
47µF
+5V
8
7
6
5
4 ARE PINS 15, 7, 6 OF TIM9904A FROM DEMUX FIGURE 30
4kΩ
φ
4
T50- MICROMETALS
2
+15V
+15V
REG
VOLTS
200pF
OUT
Figure 32. Isolated Synchronous VFC
V
24 TURNS
3
0.02µF
7815
–V
+V
S
100Ω
1.65kΩ
Rev. C | Page 21 of 28
S
1
2
3
4
5
6
7
8
0.02µF
SYNCHRONOUS
VOLTAGE-TO-
FREQUENCY
CONVERTER
2N6659
AD652
1
CK
MYLAR
0.01µF
2
Q
–15V
+5V
+15V
'74
driven by the ϕ outputs of the clock chip. Remember that data
at the comparator input of the SVFC is loaded on the falling
edge of the clock signal and shifted out on the next rising edge.
Note that the frequency signals for each data channel are
available at the frequency output pin of each FVC.
10µH
2N6659
Q
D
1
2
3
4
5
6
7
8
3
20kΩ
16
15
14
13
12
11
10
9
SYNCHRONOUS
TRANSFORMER
MPX INPUT
1.65kΩ
VOLTAGE-TO-
FREQUENCY
CONVERTER
PICO 31080
100Ω
AD652
1mA
φ
3
VOLTS
OUT
V
ISOLATION BARRIER
CK
4
0.02µF
500Ω
'74
–V
1nF
+V
S
+5V
S
Q
D
REFERENCE
1
2
3
4
5
6
7
8
AND
SYNCHRONOUS
5
6
7
8
5V
VOLTAGE-TO-
FREQUENCY
CONVERTER
D
AD652
SHOT
ONE
Q
Q
ISOLATOR
OPTO-
FLOP
6N137
"D"
CK
16
15
14
13
12
11
10
9
16
15
14
13
12
11
10
9
4
3
2
1
FREQUENCY
OUTPUT
3kΩ
φ
4
1kΩ
1nF
AD652