Saturable inductor commutation for zero voltage switching in DC-DC converter

A method of high-frequency switching is presented. In this method, a small saturable inductor is used for zero-voltage switching. The saturating condition of the inductor is controlled by a PWM (pulse-width modulation) controller with a saturable core or a current transformer. The zero-voltage switching for removing the switching losses and the switching noises is realized without increasing the conduction loss due to the resonant current. A DC-to-DC converter of 90% efficiency with 1-MHz switching frequency was obtained using this method.<>