Journal Article
Understanding Sigma-Delta Modulation: The Solved and Unsolved Issues
Journal of the Audio Engineering Society · Volume 56 · Issue 1/2 · pp. 49–64 · January 2008
Abstract
[Feature] Sigma–delta modulation is the most popular form of analog-to-digital conversion used in audio applications. It is also commonly used in D/A converters, sample-rate converters, and digital power amplifiers. In this tutorial the theory behind the operation of sigma–delta modulation is introduced and explained. We explain how performance is assessed and resolve some discrepancies between theoretical and experimental results. We discuss the issues of usage, such as limit cycles, idle tones, harmonic distortion, noise modulation, dead zones, and stability. We characterize the current state of knowledge concerning these issues and look at what are the most significant problems that still need to be resolved. Finally, practical examples are given to illustrate the concepts presented.
