CD4046BC Datasheet, PDF (12/14 Pages) Fairchild Semiconductor – Micropower Phase-Locked Loop

Design Information (Continued)
Characteristics
VCO Component
Selection
Using Phase Comparator I
VCO Without Offset
VCO With Offset
R2 = ∞
Given: f_o.
Use f_o with
Figure 5 to
Given: f_o and f_L.
Calculate f_min
from the equation
determine R1 and C1. f_min = f_o − f_L.
Using Phase Comparator II
VCO Without Offset
VCO With Offset
R2 = ∞
Given: f_max.
Calculate f_o from
the equation
Given: f_min and f_max.
Use f_min with
Figure 6 to
to determine R2 and
C1.
Use f_min with Figure 6 to
determine R2 and C1.
Calculate
Calculate
Use f_o with Figure 5 to
determine R1 and C1. Use
from the equation
Use
with Figure 7
to determine ratio
R2/R1 to obtain R1.
with Figure 7
to determine ratio R2/
R1 to obtain R1.
References
G.S. Moschytz, “Miniaturized RC Filters Using Phase-Locked Loop”, BSTJ, May, 1965.
Floyd Gardner, “Phaselock Techniques”, John Wiley & Sons, 1966.
www.fairchildsemi.com
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