
4
C
Function Generator Output (
): V
CC
=13.1V, T
A
=25C
=ArcTan V
V
cos
For
A
=45, 90, 135, 180, 225, 270, (Desired angle)
(
A
-
M
)24.0
Temperature Sensitivity: V
CC
=13.1V
MT
=
M
(T=25C) -
M (-20C2T2+85C)
(
MT
)23.5C, -20C2T2+85C
Voltage Sensitivity: T
A
=25C
MV
=
M
(V
CC
=13.1V) -
M
(11.3V2V
CC
215V)
(
MV
)22, 11.3V2V
CC
215V
sine
B+
100
W
ZENER
5.4V
SINE
80mH
225
80mH
225
B+
15
18V
G
R2
2k
W
2k
W
1k
W
E
Q
TACH INPUT
R
180k
W
*
C
OUT
1
m
F
±
10%
R1
1k
W
C
T
0.01
m
F
S
Q
O
F
O
N
C
P
D
V
Z
V
S
V
B
G
* ADJUST FOR TRIMMING
V
C
V
C
V
R
S
Q
I
C
P
+
CS289
Figure 1. Functional Diagram of CS289 Circuit.
The input frequency is buffered through a transistor, then
applied to the charge pump for frequency-to-voltage con-
version (Figure 1). The charge pump output voltage, E
,
will range from 2.1V with no input (
= 0) to 7.1V at
=
270. The charge that appears on C
T
is reflected to C
OUT
through a Norton amplifier. The frequency applied at
S
Q
IN charges and discharges C
T
through R
1
and R
2
. C
OUT
reflects the charge as a voltage across resistor R
T
.
Circuit Description
Charge Pump
Function Generator/Sine and Cosine Amplifiers
The output waveforms of the sine and cosine amplifiers
are derived by On-Chip Amplifier/Comparator circuitry.
The various trip points for the circuit (i.e. 90, 180, 270)
are determined by an internal resistor divider connected
to the voltage regulator. The voltage E
is compared to
the divider network by the function generator circuitry.
Use of an external zener reference at V
Z
allows both sine
and cosine amplifiers to swing positive and negative with
respect to this reference. The output magnitudes and
directions have the relationship as shown in Typical
Characteristics diagrams.
Note: Pin connections referenced are for the 14L DIP.