XR2212 Exar Corporation, XR2212 Datasheet - Page 13

• Manufacturer Part Number: XR2212
• Description: Precision Phase-Locked Loop
• Manufacturer: Exar Corporation

b) Choose timing resistor R
c) Choose timing capacitor, C
d) Calculate R
frequencies is desired, set f
desired range.
to 100k . This choice is arbitrary. R
tuned with a series potentiometer, R
Equation 1.
Figure 10 and design equation 5). If a range of output
frequencies are desired, set R
Rev. 2.01
Signal
Input
Output
F1 = Nfs
1
0.1 F
to set tracking bandwidth (see
f = f
2
4
Figure 12. Circuit Connection for Frequency Synthesizer
max
0
to be in the range of 15k
- f
0
F
to be at mid-point of the
O
min
= F1/N
%N
0
1
1K
to get:
5
from Figure 7 or
X
Detector
16
Phase
.
0
can be fine
14
74LS90
Similar
VCO
or
0.1 F
10
C
O
C
13
13
1
e) Calculate C
12
If a single fixed output frequency is desired, set R
get:
design equation 4). For most applications,
recommended, thus:
1
V
Note
All component values except R
nearest standard value.
CC
R
R
1
0
V
CC
0.1 F
1
to obtain desired loop damping. (See
9
7
11
C
0
f = 0.1 f
= NC
Reference
Internal
0
/4
0
0
6
8
XR-2212
can be rounded off to the
= 1/2 is
1
to