TC9400/9401/9402
FIGURE 7-2:
F/V SINGLE SUPPLY F/V CONVERTER
V+ = 10V to 15V
14
10k
6 GND
6.2V
.01µF
10k
V
REF
OUT 5
2 Zero
Adjust
V+
Offset
Adjust
Frequency
Input
33k
0.01µF
1.0k
11 DET
GND
IN914
1.0M
I
BIAS
V
REF
V
SS
7
0.1µF
1.0k
100k
4
I
IN
47pF
3
1M
Amp Out 12
6
V
OUT
.001µF
V
DD
TC9400
500k
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.
7.3
Input Buffer
FIGURE 7-3:
0.5µsec
Min
Input
F/V DIGITAL OUTPUTS
5.0µsec
Min
F
OUT
and F
OUT
/2 are not used in the F/V mode. How-
ever, these outputs may be useful for some applica-
tions, such as a buffer to feed additional circuitry. Then,
F
OUT
will follow the input frequency waveform, except
that F
OUT
will go high 3µsec after F
IN
goes high;
F
OUT
/2 will be square wave with a frequency of
one-half F
OUT
.
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
Delay = 3µsec
F
OUT
/2
2002 Microchip Technology Inc.
DS21483B-page 13
©
MICROCHIP [ MICROCHIP TECHNOLOGY ]
