Dynamic current sharing analyses for multiphase buck VRs

For high-control-bandwidth multiphase buck voltage regulators, this paper addresses the issue of dynamic current sharing among interleaved phases, especially under repetitive high-frequency load transients. The beat-frequency oscillation phenomenon of phase currents is identified and explained by a proposed small-signal model including the sideband information. To reduce the sideband frequency component while not impacting the control loop´s phase margin, the notch filter solution is proposed. Dynamic current sharing improvements with this method are proven by the experimental results for different control structures