The paper will present a novel Soft Switching Two Transistor Flyback Topology which utilizes the energy contained in the parasitic elements of the circuit to create soft commutation for the primary power switchers. This topology is highly suitable for medium power applications, such as PD 3.1. This topology eliminates the limitation associated with classical flyback topology, such as the voltage stress on the primary switch in applications with higher output voltage required by PD 3.1. In this topology the leakage inductance energy is harvested and mostly transferred to the secondary and a small portion is used to obtain zero voltage wiring on both primary switchers. There is no ringing nor spiking across all the switching elements in the primary and secondary. As a result, this topology can yield very high efficiency in all the operating conditions.
