A quadratic buck converter with lossless commutation

High switching frequency associated to soft commutation techniques is a trend in switching power converters. Following this trend, a buck PWM power converter is presented, where the DC voltage conversion ratio has a quadratic dependence on duty-cycle, providing a large step-down. By introducing two resonant networks, soft switching is attained, providing high efficient operating condition for wide load range at high switching frequency. Contrarily to most of the power converters that apply soft switching techniques, the switches are not subjected to high switch voltage or current stresses and, consequently, present low conduction losses. This paper describes the principle of operation, theoretical analysis, relevant equations and simulation and experimental results for this type of power convertor