Two-transistor Zeta-flyback DC-DC converter with reduced transistor voltage stress

A two-transistor Zeta-flyback DC-DC converter along with experimental results is introduced. The proposed converter topology is the extension of the single-transistor Zeta-flyback converter. With the incorporation of an additional transistor and two clamping diodes on the primary side of the transformer of the single-transistor Zeta-flyback converter, a two-transistor Zeta-flyback converter is proposed. High transistor voltage stress owing to the parasitic ringing seen in the single-transistor Zeta-flyback converter is reduced in the proposed converter. Furthermore, the voltage stresses of the transistors are reduced to the DC input voltage V _I. Experimental results from a 10 V/30 W, 100 kHz laboratory prototype are presented.