Hybrid DC-DC converters combining charge-pump and inductor based topologies: general study and an original reconfigurable topology integrated implementation.

The need for reduced size DC-DC converters together with the importance of EMI regulations in the automotive environments is pushing towards DC-DC converters increased integration and magnetic element elimination or at least reduction. In this context this PhD work initially focused on the analysis of existing switched-capacitor converters solutions, providing an extensive analysis and comparison of the most common topologies proposed in literature, detailing the main advantages and drawbacks of the different solutions. After this initial stage, the research work focused on hybrid DC-DC converters combining charge-pump and inductor-based topologies, with the goal of overcoming the switched-capacitor converters limitations while also guaranteeing reduced magnetic element requirements and/or switches voltage stress if compared to standard inductor based solutions. With this goal in mind, some interesting topologies proposed in literature were analyzed and used as a starting point to develop a number of novel solutions. Some of these solutions were also implemented and tested experimentally to demonstrate their feasibility and study their properties in a practical real-world scenario. A great deal of work was carried out in inventing and designing a topology combining reconfigurability with hybridization to yield buck-boost capability, wide conversion ratios and reduced magnetic element requirements. Starting from this novel solution, an integrated hybrid step-up DC-DC converter was implemented to demonstrate the topology hybrid modes operation. Overall this PhD work shows that hybrid converters are an interesting solution where full output voltage regulation or wide conversion ratios ranges are requested. These converters are also particularly interesting as a mean of obtaining high-gain topologies, that could be useful also in application fields different from automotive lighting.