A new isolated current-fed PWM DC-DC converter with small inductance and no deadtime operation

A new isolated current-fed PWM DC-DC converter with small inductance and no deadtime operation is presented and analyzed. The new topology has 3.5 times smaller inductance than that of current-fed full-bridge converter, thus having faster transient response speed. Other characteristics include simple self-driven synchronous rectification and housekeeping, smaller output filter capacitance, and lower voltage stress on all primary side power switches. Additionally, it has no start-up problem that traditional current-fed full-bridge topologies suffer. A 48V/100W prototype DC-DC converter has been tested for the verification of the principles. Both simulations and experiments verify the feasibility and advantages of the new topology.