TC9402 TELCOM [TelCom Semiconductor, Inc], TC9402 Datasheet - Page 12

• Manufacturer Part Number: TC9402
• Description: VOLTAGE-TO-FREQUENCY/FREQUENCY-TO-VOLTAGE CONVERTERS
• Manufacturer: TELCOM [TelCom Semiconductor, Inc]

Output Filtering
imposed on a DC level. The ripple will be rejected if the
TC9400 output is converted to a digital value by an integrat-
ing analog to digital converter, such as the TC7107 or
TC7109. The ripple can also be reduced by increasing the
value of the integrating capacitor, although this will reduce
the response time of the F/V converter.
eliminated without affecting the F/V's response time by
using the circuit in Figure 10. The circuit is a capacitance
multiplier, where the output coupling capacitor is multiplied
by the AC gain of the op amp. A moderately fast op amp,
such as the TL071, should be used.
3-298
TC9400
TC9401
TC9402
The output of the TC9400 has a sawtooth ripple super-
The sawtooth ripple on the output of an F/V can be
Frequency
Input
Note: The output is referenced to pin 6, which is at 6.2V (Vz). For frequency meter applications,
a 1 mA meter with a series-scaling resistor can be placed across pins 6 and 12.
100k
Offset
Adjust
33k
10k
6.2V
0.01 F
500k
Figure 9.
.01 F
IN914
0.1 F
F/V Single Supply F/V Converter
V +
10k
FREQUENCY-TO-VOLTAGE CONVERTERS
1.0k
1.0k
1.0M
11
6
2
GND
ZERO
ADJUST
DET
I
BIAS
V + = 10V to 15V
TC9400
100k
TC9400
GND
V
V
AMP OUT
6
REF
V
DD
REF
14
AMP OUT
7
V
REF
OUT
V
VOLTAGE-TO-FREQUENCY/
SS
I
IN
4
GND
OUT
I
Figure 10.
IN
5
3
12
TELCOM SEMICONDUCTOR, INC.
5
3
12
6
1M
47pF
1M
47pF
Ripple Filter
.001 F
200
1M
.01 F
.001 F
2
3
V
OUT
+
–
1M
7
4
+5
–5
6
TL071
0.1 F
V
OUT