Investigation of the output current and its applications for the multiphase buck converter

Quantitative analysis of the output current for the multiphase buck converter facilitates the optimal design of the converter. This paper quantifies the output current and its ripple cancellation effect. A universal formula has been derived to express the output current of multiphase buck converter with any number of phases operating at both continuous conduction mode (CCM) and discontinuous conduction mode (DCM). Therefore, output capacitor ripple current can be calculated and the suitable capacitor can be selected based on that. Major practical factors affecting the output current are also discussed. Simulation and experiment validate the proposed methodology to be used as an accurate design tool.