Analyzing Current Ripple in Variable-Frequency Boost Converter

Electromagnetic interference (EMI) remains one of the main problems in switch mode power supplies (SMPS). Various EMI reduction schemes for switching converters using switching modulation have been proposed over the last decades. These variable-frequency (VF) modulation techniques include quasi-random system clock generation, random or quasi-random modulation of the system clock frequency, frequency modulation (FM) of the system clock, sigma-delta modulation, chaotic peak current control and hysteresis control. Voltage and current ripple have been considered a major problem with VF-modulated power supplies. The analysis of input current in boost converter using VF modulation is presented in this paper.