A family of high power density bus converters

This paper begins by reviewing current bus converters and exploring their limitations. Then a family of inductor-less bus converters is proposed to overcome the limitations. In the new bus converter, magnetizing current is used to achieve zero-voltage-switching (ZVS) turn-on for all switches. The resonant concept is used to achieve zero-current-switching (ZCS) without turn-off loss and body diode loss. Meanwhile, the self-driven method can be easily applied to save drive loss in the synchronous rectifiers. Based on these concepts, a full-bridge bus converter is built in the quarter-brick size to verify the analysis. The experimental results indicate that it can achieve 95% efficiency at 500 W, 12 V/45 A output. Compared with industry products, this topology can dramatically increase the power density.