XR2206D EXAR [Exar Corporation], XR2206D Datasheet - Page 10

• Manufacturer Part Number: XR2206D
• Description: Monolithic Function Generator
• Manufacturer: EXAR [Exar Corporation]

Frequency-Shift Keying
The XR-2206 can be operated with two separate timing
resistors, R
respectively, as shown in Figure 13. Depending on the
polarity of the logic signal at Pin 9, either one or the other
of these timing resistors is activated. If Pin 9 is
open-circuited or connected to a bias voltage
R
be keyed between two levels. f
f
For split-supply operation, the keying voltage at Pin 9 is
referenced to V
Output DC Level Control
The dc level at the output (Pin 2) is approximately the
same as the dc bias at Pin 3. In Figure 11 , Figure 12 and
Figure 13 , Pin 3 is biased midway between V+ and
ground, to give an output dc level of
1
1
XR-2206
1V, only R
= 1/R
is activated. Similarly, if the voltage level at Pin 9 is
Rev. 1.03
1
C and f
1
2
and R
is activated. Thus, the output frequency can
-
.
2
= 1/R
2
, connected to the timing Pin 7 and 8,
2
C
1
and f
Figure 14. Circuit for Pulse and Ramp Generation.
2
, as:
V
+
/2.
R
R
1
2
C
2V, only
1
5
6
9
8
7
V
Switches
CC
Current
VCO
10
+
10 12
5.1K
1 F
APPLICATIONS INFORMATION
Sine Wave Generation
Without External Adjustment
Figure 11 shows the circuit connection for generating a
sinusoidal output from the XR-2206. The potentiometer,
R
maximum output swing is greater than V
typical distortion (THD) is < 2.5%. If lower sine wave
distortion is desired, additional adjustments can be
provided as described in the following section.
The circuit of Figure 11 can be converted to split-supply
operation, simply by replacing all ground connections
with V
connected to ground.
V
1
CC
4
at Pin 7, provides the desired frequency tuning. The
Shaper
Mult.
Sine
And
-
3
. For split-supply operation, R
1 F
24K
R
5.1K
3
+1
XR-2206
+
10 F
16
15
14
13
11
2
5.1K
V
CC
Duty Cycle =
Sawtooth Output
Pulse Output
f
3
C
2
can be directly
R
R
1
1
+
R
/2, and the
1
1
R
R
2
2