Introduction

Abstract

Phase-locked loops (PLLs) are a well established and very widely used circuit technique in modern electronic systems. They involve a curious blend of analogue and digital techniques, operate with both linear and nonlinear behaviour and are amenable to continuous, sampled or even chaotic analysis. They also result in amongst the most elegant of electronic circuit designs. Although occasionally regarded as something of a ‘black art’, the truth is that the subject is most amenable to accurate analysis and rational design once the fundamental principles are clearly understood.