Principle and topology derivation of single-inductor multi-input multi-output DC-DC converters

Single-inductor multi-input multi-output (SI-MIMO) dc-dc converters are attractive in the engineering applications due to the advantage of high power density and low cost. In order to explore as many as possible SI-MIMO topologies, this paper proposes a simple and effective topology derivation principle which only requires three steps. Firstly, three basic cells consisting of a single inductor and multiple sets of unidirectional switches as well as inputs/outputs are proposed. Secondly, integrate them with the inductor branch of the typical single-input single-output converters. Finally, implement the topology simplification by removing unnecessary switches/diodes. Based on the proposed principle, a large number of SI-MIMO topologies are derived from buck, boost, buck-boost and non-inverting buck-boost converters in the paper. With more topology choices having different performance characteristics, it is very beneficial for engineers to gain an optimized design that a preferred one can be selected out after comprehensive comparison. As an example, topology comparison and selection among a family of single-inductor single-input dual-output converters is also conducted in the paper. Besides, performance analysis, design considerations and simulation/experiment results of the selected optimum topology are demonstrated in detail to verify its advantages.