TC9402 TELCOM [TelCom Semiconductor, Inc], TC9402 Datasheet - Page 13

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

VOLTAGE-TO-FREQUENCY/
FREQUENCY-TO-VOLTAGE CONVERTERS
F/V POWER-ON RESET
ally be at its maximum value when power is first applied. This
condition remains until the first pulse is applied to f
frequency-measurement applications this is not a problem,
because proper operation begins as soon as the frequency
input is applied.
In F/V mode, the TC9400 output voltage will occasion-
TELCOM SEMICONDUCTOR, INC.
100k
1 F
f IN
V DD
3
4
CLRA
1k
A
V CC
16
Figure 11.
IN
. In most
CD4538
B
5
V SS
Power-On Operation/Reset
1000pF
8
R
2
zero at power-on without a frequency input. In such cases,
a capacitor connected from pin 11 to V
sufficient to pulse the TC9400 and provide a power-on reset
(see Figure 11A). Where predictable power-on operation is
critical, a more complicated circuit, such as Figure 11B, may
be required.
11
In some cases, however, the TC9400 output must be
THRESHOLD
DETECTOR
1
C
Q
TC9400
6
14
f IN
V DD
(A)
(B)
To TC 9400
DD
will usually be
TC9400
TC9401
TC9402
3-299
1
2
3
4
5
6
7
8