A two-phase high step down coupled-inductor converter for next generation low voltage CPU

In this paper, a novel two-phase high step down coupled-inductor converter for next generation low voltage CPU is proposed. This converter has a very high step down characteristic as V_o/V_i= D/4. The switching loss and noise of all switching elements are sufficiently reduced because the drain-source voltages at switching periods are reduced to a quarter of the input source voltage. Low withstand voltage MOSFETs with low on resistance and low Qg(total gate charge) characteristics are possible to use for the all switching elements because the maximum voltage stresses of the main switches and the synchronous rectifier switches are reduced to a half and a quarter of the input source voltage respectively. Further, the branch currents flowed through the paralleled converters are automatically and mostly balanced without the current detection and balance control. The above fine characteristics are simply achieved with three additional capacitors.