High Frequency Effect of Switching Time in Randomly Controlled DC-DC Converters

摘要

We propose in this paper a study of the switching time effect in DC-DC converters controlled by Random Pulse Width Modulation (RPWM). Generally, switching time is neglected and output voltage is approximated by a perfect rectangular signal. In this work, switching time is taken into account by assuming output voltage to be trapezoidal. A modulation principle based on a random triangular carrier is first proposed. Using switching functions, an accurate analytical model of output voltage Power Spectral Density (PSD) is proposed. The effect of fixed and randomized switching time is then analyzed at low and high frequencies.