A new matrix integrated magnetics (MIM) structure for low voltage, high current DC-DC converters

Abstract

A new matrix integrated magnetics (MIM) structure is proposed for low voltage, high current DC-DC converter applications. The proposed structure enables the design of low profile magnetics resulting in better core utilization, higher inductance per secondary winding and improved efficiency. The principal of operation of the MIM structure is explained as applicable to a half-bridge current doubler rectifier (CDR) controlled according to the symmetrical modulation scheme. The proposed concept is, however, applicable to a variety of DC-DC converter topologies and control algorithms. The structure is cellular in that replicating elementary cells enables the development of higher current modules without compromising performance and power density metrics. It enables the development of novel interleaving schemes to reduce switching ripple in inductor current and output voltage. It also facilitates integration for multiple output and multiphase interleaved DC-DC converters with integrated magnetics. Experimental results from 3.3 V/100 W CDR prototype are presented to illustrate the validity of the proposed MIM structure.