Diodes as pseudo active elements in high frequency DC/DC converters

An approach to realizing zero voltage switching in the entire family of high-frequency DC/DC converters is proposed. utilizing the parasitic associated with the diode stored charge, it is shown that the diode reverse current established for charge removal can be used advantageously to accomplish soft switching. The resulting converter topologies differ from their hard-switched counterparts only by the presence of a resonant capacitor. Device and component stresses are moderate compared to existing quasiresonant and resonant techniques. Converter analysis is complex as a result of the dominant diode nonlinearities, and no closed-form expressions are possible. Converter transfer characteristics are obtained through simulation, and operating limits are analytically obtained. The concept is validated by experimental results on buck, buck-boost, and boost converters rated approximately 100 W and operating at frequencies around 1 MHz.