tc9400 Microchip Technology Inc., tc9400 Datasheet - Page 11

• Manufacturer Part Number: tc9400
• Description: Voltage-to-frequency / Frequency-to-voltage Converters
• Manufacturer: Microchip Technology Inc.

Trimming the reference voltage is not recommended
for high accuracy applications unless an op amp is
used as a buffer, because the TC9400 requires a low-
impedance reference (see Section 2.5 “Voltage Ref-
erence (VREF)”, V
mation).
FIGURE 4-2:
© 2007 Microchip Technology Inc.
(0 to 10V)
Voltage
Input
910 kΩ
910 kΩ
R1
R2
F/S Freq.
100 kHz
10 kHz
1 kHz
REF
Gain
Component Selection
R3
100 kΩ
Voltage-to-Frequency.
Offset
100 kΩ
pin description, for more infor-
20 kΩ
91 kΩ
Rp
R4
R5
2200 pF 4700 pF
180 pF
27 pF
C
REF
Analog Ground
5.1 VZ
470 pF
5.1 VZ
75 pF
C
D2
1 µF
D1
INT
C
INT
0.1 µF
100 kΩ
1.2 kΩ
C
REF
The circuit of
CMOS logic operating at 12V to 15V. TTL or 5V CMOS
logic can be accommodated by connecting the output
pull-up resistors to the +5V supply. An optoisolator can
also be used if an isolated output is required; also, see
Figure
12
11
5
3
2
6
7
1
Threshold
Detect
Amp Out
C
I
Zero Adjust
GND
V
I
IN
BIAS
REF
REF
TC9400/9401/9402
4-3.
+12 to +15V
TC9400
V DD
V
SS
14
4
Figure 4-2
Common
F
Output
OUT
F
OUT
/2
8
10
9
will directly interface with
10
kΩ
DS21483D-page 11
Digital
Ground
10 kΩ
Output
Frequency