Two-phase high efficiency interleaved buck converter with improved step-down conversion ratio and low voltage stress

A two-phase interleaved buck converter (IBC) providing a high step-down conversion ratio is proposed in this study. The proposed IBC uses a switch-capacitor cell to achieve a high step-down conversion ratio compared to the conventional IBC. The cell consists of two parallel switches and two crossly placed identical capacitors. These identical capacitors are charged in series and discharged in parallel by producing a lower output voltage compared to the conventional IBC at the same duty ratio. The proposed converter provides less voltage and current stresses. The operation principle, the ripple and the average current through the inductors are described in continuous conduction mode. The boundary load condition is also determined. By describing the charging and discharging of the two identical capacitors of the cell, the capacitance value is determined. The losses and efficiency are analysed, and 96.33% efficiency is achieved. Finally, the proposed converter is implemented and experimental results are provided.