Computing the Separatrix Cycle That Occurs in a Second-Order,Type II Phase-Lock Loop

Dr. John Stensby

Department of Electrical and Computer Engineering
University of Alabama in Huntsville

November 3, 2000

Abstract

For motivational purposes, a short qualitative description is given of phase lock loops (PLLs) and their applications. Then, a model is developed for a commonly-used, second-order PLL. Next, a discussion is given of the model's global phase plane behavior and how it is influenced by a separatrix cycle. Finally, a numerical algorithm is given for computing the separatrix cycle.