Limitations of the classical phase-locked loop analysis

TL;DR

This paper critically examines the limitations of classical PLL analysis, highlighting that simplified models and simulations can overlook hidden oscillations, potentially leading to incorrect assessments of PLL circuit operability.

Contribution

It demonstrates the shortcomings of traditional analysis methods for PLLs, emphasizing the importance of nonlinear analysis to detect hidden oscillations.

Findings

Classical models may miss hidden oscillations.

Simulations can lead to incorrect conclusions.

Nonlinear analysis reveals limitations of traditional methods.

Abstract

Nonlinear analysis of the classical phase-locked loop (PLL) is a challenging task. In classical engineering literature simplified mathematical models and simulation are widely used for its study. In this work the limitations of classical engineering phase-locked loop analysis are demonstrated, e.g., hidden oscillations, which can not be found by simulation, are discussed. It is shown that the use of simplified dynamical models and the application of simulation may lead to wrong conclusions concerning the operability of PLL-based circuits.