Datasheet
VFC320
9
SBVS017A
FIGURE 12. Remote Transducer Readout via Fiber Optic Link (Analog and Digital Output).
FIGURE 13. Bipolar input is accomplished by offsetting the
input to the VFC with a reference voltage.
Accurately matched resistors in the REF101
provide a stable half-scale output frequency at
zero volts input.
FIGURE 14. Absolute value circuit with the VFC320. Op
amp, D
1
and Q
1
(its base-emitter junction
functioning as a diode) provide full-wave
rectification of bipolar input voltages. VFC
output frequency is proportional to | e
1
|. The
sign bit output provides indication of the input
polarity.
3510B
VFC320
0.01µF
C
1
3270pF
C
2
R
3
40.2kΩ
R
2
100kΩ
R
1
11kΩ
4.7kΩ 4.7kΩ
+V
CC
V
IN
8.66kΩ
R
4
D
1
IN4154
2N2222
Sign Bit
Out
e
1
Bipolar
Input
Q
1
f
OUT
–
+
Integrator
Current
20kΩ20kΩ
REF101
VFC320
10
13
7
5
7
+15V
8
1
+10V to –10V
Input
4
10V
30kΩ
12
0.01µF
+15V
3
3300pF
11
14
–15V
0 to
10kHz
Output
1
Gain Adjust
6
5
2kΩ
VFC320
V/F
V
IN
f
OUT
Clock
BCD
Counter
Driver
INA101
Transducer
Precision DC
levels down to
10mV full scale
FOT FOR
Display
VFC320
F/V
V
OUT
f
IN
Analog
Output
Digital
Output
0.005% Linearity
Instrumentation
Amp