Modeling and Analysis for Beat-Frequency Current Sharing Issue in Multiphase Voltage Regulators

Under high-frequency repetitive load transients, multiphase voltage regulators (VRs) suffer from beat-frequency oscillations of the phase currents. To investigate this issue, this paper develops a methodology based on the multifrequency model with describing functions. The influences from the interleaving operation are identified. After that, the analysis is extended to studying of the higher-order beat-frequency issue. Then, a solution by applying coupled inductors is proposed. Experimental and simulation results are presented as verification.