Direct 48 V to 6 V Automotive Hybrid Switched-Capacitor Converter with Reduced Conducted EMI

With the rapid growth and development of high-density power converter topologies, including hybrid switched-capacitor converters, data-centers have seen a shift towards 48 V bus architectures for reduced transmission losses. In parallel, the automotive industry has similarly benefited from these advancements, with the proliferation of 48 V batteries allowing for reduced cable weight. However, the latter application space comes with additional challenges such as automotive-qualified component selection and the need to meet rigorous electro-magnetic interference (EMI) standards. This work proposes a new interleaved-input, single-inductor Dickson converter with a high conversion ratio (8:1) for 48 V automotive applications. The impacts of operating frequency on efficiency and EMI performance are explored, as well as EMI mitigation techniques such as spread-spectrum frequency modulation (SSFM). A hard-ware prototype was built to demonstrate these concepts, and was characterized with respect to the CISPR 25, Class 5 EMI standards required for many automotive applications.