xr215a Exar Corporation, xr215a Datasheet - Page 25

• Manufacturer Part Number: xr215a
• Description: Monolithic Phase-locked Loop
• Manufacturer: Exar Corporation

The circuit was designed to operate with commercially available monolithic programmable counter circuits using TTL
logic, such as MC4016, SN5493 or equivalent. The digital or analog tuning characteristics of the VCO can be used to
extend the available range of frequencies of the system, for a given setting of the timing capacitor C
Typical input and output waveforms for N = 16 operation with f
Rev. 1.01
(Optional)
Binary
Range Select
C
1K
c
20K
Rx
4K
-5V
Figure 23. Circuit Connection For Frequency Synthesis
Figure 24. Typical Input/Output Waveforms for N=16
11
12
10
6
V
U1
9
EE
13
C
Phase
Comp.
VCO
0
Bottom: VCO Output (1.6MHz)
14
C
20K
1
5
XR-215A
Top: Input (100kHz)
2
C
16 V
3
1
1
+5V
25
Op
Amp
CC
7
0.1 F
15
s
4
8
= 100kHz and f
VCO Output
10K
Fo=NFs
20K
Cc
Cc
o
= 1.6MHz are shown in Figure 24.
Level
Shifter
Input
F=Fs
XR-215A
SN7493 or Equivalent
0
.
N