The short winding path coupled inductor voltage regulators

In today's CPU Voltage Regulator(VR) industry, coupled inductor VRs have begun to replace the non-coupled VRs for their better performances. However, today's coupled inductor implementations have long winding paths, which is not preferred in the high current CPU VR application. In this paper, several short winding path coupled inductor structures for 2 and more phase coupled inductors are proposed. Their precise reluctance models are illustrated and their design guidelines based on their precise reluctance models are also shown. The experimental results verify the proposed structures, their models and their design procedures.