Design optimization of coupled inductor multiphase synchronous buck converter

In this paper a detailed design optimization technique for multiphase synchronous buck converters is discussed. As the voltage regulator modules (VRMs) for future microprocessors require power delivery at high frequency, low voltage and high current, it is shown that, coupled inductor technique is well suited. As there is no method existing to pre estimate the losses and hence the efficiency of the DC-DC converter, a new method with a new coupled core structure is proposed and analyzed. It is possible to reduce the ripple by nearly 20% and by optimization it is shown that, a total loss reduction of nearly 30% is possible by going for this type of coupling. Thus, the improvement in efficiency is expected to be around 3%. A numerical optimization of the magnetic core is carried out on a 20 A, 50 KHz, 12/1.1 volt designs