Active asynchronous secondary side voltage clamping

An asynchronous active voltage clamp for the secondary side of switching DC-DC converters is proposed. The control of the proposed clamping circuit is independent from the main converter, thus allowing use of a physically small inductor and offering increased control over the clamping operation. Measurements on a 1 MHz implementation of the asynchronous active voltage clamp on the secondary side of a prototype 220 kHz phase shifted full bridge DC-DC converter confirm the effectiveness of the voltage clamping and the improved converter efficiency.