New zero-current switching PWM converters using power MOSFET for lower power applications

In this paper, a new ZCS-PWM DC/DC power converter in which the auxiliary resonant circuit consists of minimum elements, a resonant inductor, a resonant capacitor and an auxiliary switch, and it is only activated during the main switch commutation is proposed, particularly for low-power applications. The main switch operating under ZCS, and auxiliary switch and main diode operating under ZCS or ZVS at both turn-on and turn-off, is also achieved. A 100 kHz, 60 W breadboarded boost converter has been implemented to verify the operation and performance of the proposed converter. The measured efficiency of the proposed scheme as a function of the output power was 89.35% at full load. Without the proposed scheme, the converter efficiency for the same load was 80.53%.