Efficient ZVS Synchronous Buck Converter with Extended Duty Cycle and Low-Current Ripple

In this paper, an efficient zero-voltage-switching (ZVS) synchronous buck converter with extended duty cycle and low-current ripple is proposed for voltage regulator module (VRM) applications. By combining series capacitor and coupled inductors, operating duty cycle is extended considerably. Also, soft switching condition for all switches is provided without any auxiliary circuit and as a result, overall efficiency is improved. In addition, by complementary operation of the main switches of the interleaved modules, the resulting output current ripple is reduced. The converter operating modes are discussed and experimental results are presented to verify the theoretical analysis.