Pulse-to-pulse voltage reproducibility efficient prediction method for high precision klystron modulator design

Abstract

Pulse-to-pulse-reproducibility in Switch Mode Power Converters can be affected by random phenomena such as switch jitter, external electromagnetic perturbations, thermal fluctuations, etc. Although many phenomena influence the reproducibility, the most important and most predictable is the jitter of the switch(es). The switch jitter influences the ripple by displacing it in time, and therefore plays a fundamental role in pulse-to-pulse reproducibility. Furthermore, when compared with other phenomena, switch jitter affects reproducibility differently depending on the converter topology (since the switch arrangement is different). In order to consider pulse-to-pulse reproducibility early in the design process of a converter (i.e. topology selection), an efficient and flexible method for estimating this performance as a function of ripple and the expected, or measured, switch jitter is necessary. This paper presents a methodology applicable to all switch mode power converters, which allows the derivation of the pulse-to-pulse reproducibility versus ripple and switch jitter (driver included). The numerically validated method uses analytical expressions derived from harmonics analysis.