cs289gdwr20 ON Semiconductor, cs289gdwr20 Datasheet - Page 5

• Manufacturer Part Number: cs289gdwr20
• Description: 20ma Air-core Tachometer Drive Circuit
• Manufacturer: ON Semiconductor

V
The above equations were used in calculating the follow-
ing values, where V
Figure 2: Alternate Trimming Method
F/V
OUT
= 2.1 + Frequency x C
4 cylinder: Freq = 200Hz, R
6 cylinder: Freq = 300Hz, R
8 cylinder: Freq = 400Hz, R
RPM
60
F/V
x # OF CYL.
OUT
= 7.1V at =270° and C
1k
2
T
x R
T
= Frequency
T
T
T
(V
R
= 320k
= 220k
= 150k
T
REG
10k
C
-0 .7)
T
C
P
T
Tachometer Application
= 0.01 F.
TRIM
5
Figure 3: DC Application
Typical values shown above apply to a nominal value of
V
will be necessary to compensate for variations in regula-
tor voltage from one unit to another.
An alternative to this adjustment is to replace R
potentiometer, as shown in Figure 2.
Partial schematic shown in Figure 3 represents one met-
hod for use with DC applications instead of frequency.
REG
of 8.5 volts. It must be realized that trimming of R
I
IN
0.7V
I
OUT/E
R
T
2.1V
C
P
2
with a
T