High frequency, soft transitions converter

A high efficiency, high power density power conversion topology is presented. This topology is compatible with higher output voltage applications such as 24 V and 48 V, where Schottky rectifiers cannot be used. The converter combines zero voltage switching across the primary switches, continuous energy transfer from the primary to the secondary and soft commutations of the output rectifiers. The soft switching of the output rectifiers minimizes the reverse recovery losses associated with ultrafast rectifiers operating at high frequency. An experimental converter using this concept is evaluated. The converter operates from an input voltage of 200 V to 430 V at 300 kHz, providing 400 W (50 V at 8 A) with efficiency of 95% at full load.<>