DocumentCode :
1240348
Title :
Phase-Locked Loop Pull-In Frequency
Author :
Greenstein, Larry J.
Author_Institution :
Bell Labs., N.J.
Volume :
22
Issue :
8
fYear :
1974
fDate :
8/1/1974 12:00:00 AM
Firstpage :
1005
Lastpage :
1013
Abstract :
A computerized procedure for obtaining the pull-in frequency of a phase-locked loop is described. The procedure, which consists of solving for the limit cycle of the out-of-lock loop and finding the frequency offset below which no solution exists, is quite general with respect to phase detector function and loop filter. It is applied in this study to the case of a second-order loop with a sinusoidal phase detector. The results of the study give normalized pull-in frequency X as a function of the damping factor \\zeta and normalized natural frequency β of the linearized closed loop. A review of several previously published investigations of this case is given, and the limitations identified point the way to the more exact solution described here. In addition, an experimental study is described which produces excellent agreement with the new results, and a curve-fitting procedure is outlined which leads to a highly accurate functional description of X in terms of β and \\zeta .
Keywords :
PLLs; Phase-locked loop (PLL); Circuits; Damping; Filters; Frequency locked loops; Limit-cycles; Phase detection; Phase frequency detector; Phase locked loops; Transfer functions; Voltage-controlled oscillators;
fLanguage :
English
Journal_Title :
Communications, IEEE Transactions on
Publisher :
ieee
ISSN :
0090-6778
Type :
jour
DOI :
10.1109/TCOM.1974.1092331
Filename :
1092331
Link To Document :
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