TC9400/9401/9402
FIGURE 7-2:
F/V SINGLE SUPPLY F/V CONVERTER
V+ = 10V to 15V
14
10k
V
DD
6
GND
.01µF
TC9400
6.2V
10k
5
3
V
OUT
REF
500k
2
Zero
Adjust
47pF
100k
V+
I
IN
Offset
Adjust
.001µF
1M
12
6
Amp Out
1.0k
0.01µF
33k
Frequency
11
V
OUT
DET
Input
GND
V
IN914
I
V
BIAS
1.0M
REF
7
SS
4
0.1µF
1.0k
100k
Note: The output is referenced to Pin 6, which is at 6.2V (Vz). For frequency meter applications,
a 1mA meter with a series scaling resistor can be placed across Pins 6 and 12.
FIGURE 7-3:
F/V DIGITAL OUTPUTS
7.3
Input Buffer
F
and F
/2 are not used in the F/V mode. How-
OUT
OUT
5.0µsec
Min
0.5µsec
ever, these outputs may be useful for some applica-
tions, such as a buffer to feed additional circuitry. Then,
F
Min
Input
will follow the input frequency waveform, except
OUT
that F
will go high 3µsec after F goes high;
OUT
IN
F
/2 will be square wave with a frequency of
F
OUT
OUT
one-half F
.
OUT
Delay = 3µsec
If these outputs are not used, Pins 8, 9 and 10 should be
connected to ground (see Figure 7-3 and Figure 7-4).
F
OUT
/2
2002 Microchip Technology Inc.
DS21483B-page 13
MICROCHIP [ MICROCHIP ]
