Speedometer/Odometer or Tachometer Application
R3
C3
R4
CCPP++
CP-
F/VOUT
VREG
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
C4
C
T
R
T
Speedo
Input
+
SQOUT
FREQIN
Gnd
R2
Gnd
Gnd
Gnd
COS+
COS-
VCC
SINE+
SINE-
BIAS
Battery
D1 R1
D2
C1
COSINE
SINE
Gnd
Speedometer
Air Core
Gauge
200W
Figure 6
R1 - 3.9, 500mW
R2 - 10k½
R3 - 3k½
CT - 0.0033µF, +/- 30 PPM/¡C
D1 - 1A, 600 PIV
D2 - 50V, 500mW Zener
R4 - 1k½
Note 1: For 58% Speed Input TMAX ² 5/fMAX where
TMAX = CT(R3+R4)
RT - Trim Resistor +/- 20 PPM/¡C 243k½
C1 - 0.1µF
C3 - 0.1µF
C4 - 0.47µF
fMAX = maximum speed input frequency
R3
C3
R4
CCPP++
CP-
F/VOUT
VREG
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
C4
C
T
R
T
Speedo
Input
+
SQOUT
FREQIN
Gnd
R2
Gnd
Gnd
Gnd
SINE+
COS+
COS-
VCC
SINE-
BIAS
Battery
D1 R1
D2
C1
COSINE
SINE
Gnd
Speedometer
Air Core
Gauge
200W
C2
1
CS8441
Air Core
Stepper Motor
200W
Odometer
Figure 7
Note 1: The product of CT and RT have a direct effect on
gain and therefore directly affect temperature compensation
T Range; 20pF to .2µF
T Range; 100k½ to 500k½
Note 4: The IC must be protected from transients above 60V and
reverse battery conditions
Note 5: Additional filtering on FREQIN lead may be required
Note 2:
Note 3:
C
R
7
CHERRY [ CHERRY SEMICONDUCTOR CORPORATION ]
