Elimination of sub-harmonic oscillation of digital average current control buck converter

The sub-harmonic oscillation of digital average current (DAC) control buck converter with single-edge modulation (trailing-edge modulation and leading-edge modulation) is investigated in this paper. It has been shown that both digital slope compensation (DSC) and digital reposition compensation (DRC) of duty ratio ac component can not be used to eliminate the sub-harmonic oscillation of DAC control buck converter with single-edge modulation. To eliminate the sub-harmonic oscillation of DAC control buck converter with single-edge modulation, a new method, called as digital triangle compensation (DTC), is proposed and studied. Simulation results are given to verify the analysis results.