Synchronous rectification technique for high-voltage single-ended power converters

Synchronous rectification (SR) has been extensively implemented in low-voltage switched-mode power conversion applications to reduce diode conduction losses. This paper addresses SR at higher voltages where the reverse recovery behaviour of the SR MOSFET's intrinsic diode is particularly challenging. A saturable inductor switching-aid circuit is introduced into a power converter in conjunction with modified delay times between the MOSFET drive signals. The technique is experimentally evaluated in a buck converter supplying a 210W load from an input voltage up to 330V.