An EMI-Compliant and Automotive-Rated 48 V to Point-of-Load Dickson-Based Hybrid Switched-Capacitor DC–DC Converter

With the move to a 48 V distribution rail in data center power delivery architectures and automotive powertrains, high performance hybrid switched-capacitor (hybrid SC) converters have become an attractive power delivery solution in both spaces. However, automotive power systems present unique design challenges due to strict electromagnetic interference (EMI) and reliability requirements. This work investigates a regulating, Dickson-based hybrid SC topology with low inherent EMI, and discusses the incorporation of control-based EMI mitigation techniques such as resonant and above resonant operation, as well as spread-spectrum frequency modulation. The impact of such techniques on efficiency in hybrid SC converters is explored, as well as passive filter designs to achieve EMI compliance. The proposed filter and modulation schemes enable this converter to meet the CISPR 25, automotive EMI standard. A 150 W hardware prototype is built and tested to demonstrate the merit of hybrid SC topologies for use in 48 V automotive systems. The converter achieves a peak efficiency of 97.1% for 48 V-to-5 V operation and meets CISPR 25, Class 5 EMI regulation limits.