AD598AD Analog Devices Inc, AD598AD Datasheet - Page 14

• Manufacturer Part Number: AD598AD
• Description: IC LVDT SIGNAL COND 20-CDIP
• Manufacturer: Analog Devices Inc
• Type: Signal Conditionerr

Specifications of AD598AD

• Rohs Status: RoHS non-compliant
• Input Type: Voltage
• Output Type: Voltage
• Interface: LVDT
• Current - Supply: 15mA
• Mounting Type: Through Hole
• Package / Case: 20-CDIP (0.300", 7.62mm)
• Bandwidth: 20kHz
• Supply Voltage Min: 13V
• Supply Voltage Max: 36V
• Digital Ic Case Style: DIP
• No. Of Pins: 20
• Operating Temperature Range: -40°C To +85°C
• Temperature Coefficient: 250ppm/°C
• Application: Proving ring-weigh scale, synchronous opeation of multiple LVDTS
• Converter Type: voltage to Frequency
• Current, Output: 6 mA (Min.)
• Impedance, Input: 200 Kiloohms (Typ.)
• Package Type: Ceramic DIP
• Temperature, Operating, Maximum: 85 °C
• Temperature, Operating, Minimum: -40 °C
• Voltage, Operating: 36 V (Max.)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

AD598
PRECISION DIFFERENTIAL GAGING
The circuit shown in Figure 26 is functionally similar to the dif-
ferential gaging circuit shown in Figure 25. In contrast to Figure
25, it provides a means of independently adjusting the scale fac-
tor of each LVDT so that both scale factors may be matched.
The two LVDTs are driven in a master-slave arrangement
where the output signal from the slave LVDT is summed with
the output signal from the master LVDT. The scale factor of the
slave LVDT only is adjusted with R1 and R2. The summed
scale factor of the master LVDT and the slave LVDT is ad-
justed with R3.
15k
15k
SCHAEVITZ E 100
A
B
D
C
MASTER LVDT
SLAVE
LVDT
Figure 26. Precision Differential Gaging
–14–
R1 and R2 are chosen to be 80.9 k resistors to give a 10 V
full-scale output signal for a single Schaevitz E100 LVDT. R3 is
chosen to be 40.2 k to give a 10 V output signal when the
two E100 LVDT output signals are summed. The output volt-
age for this circuit is given by:
V
0.015 F
OUT
0.1 F
0.1 F
– V
– V
V
OUT
10
10
8
2
3
4
5
6
7
8
9
1
2
3
4
5
6
7
9
0.1 F
1
0.1 F
=
(V
(V
EXC 1
EXC 2
LEV 1
LEV 2
FREQ 1
FREQ 2
B1 FILT
B2 FILT
EXC 1
EXC 2
LEV 1
LEV 2
FREQ 1
FREQ 2
B1 FILT
B2 FILT
V
–V
V
–V
B
B
V
V
A
A
S
S
A
A
–V
+V
–V
AD598
AD598
B
B
V
+
B
B
FEEDBACK
FEEDBACK
V
V
)
)
OFFSET 2
OFFSET 2
OFFSET 1
OFFSET 1
OUT FILT
OUT FILT
C
C
SIG OUT
SIG OUT
SIG REF
SIG REF
–V
+V
A1 FILT
A2 FILT
A1 FILT
A2 FILT
(V
(V
D
D
•
+V
+V
C
C
V
V
R2
R1
0.1 F
0.1 F
A
A
S
S
–V
V
13
12
16
13
12
20
19
18
17
16
15
14
11
20
19
18
17
15
14
11
•
D
D
500 A
)
)
+ V
+ V
R3
R2
R1
•
R3
40.2k
0.33 F
0.1 F
0.33 F
0.1 F
500 A R3.
R2
80.9k
R1
80.9k
V
FULL SCALE
OUT
REV. A
10V