Large Signal Analysis on Variations of the Hybridized Dickson Switched-Capacitor Converter

Dickson-type dc-dc converters have gained renewed interest in recent years due to their best-in-class volt-amp switch utilization. In addition, hybrid switched-capacitor (HSC) structures increase passive component utilization while avoiding the slow-switching limit (SSL), and yet, most HSC work to date has done little to assess large signal voltage ripple behavior and subsequent passive utilization limits. This work contributes a comprehensive review of contemporary Dickson-type HSC converters before introducing eight fundamental reduced HSC Dickson structures, including three that are proposed here. Analysis allowing characterization of large signal operating points, capacitor sizing regimes, switching schemes, and maximum allowable power throughput is introduced. The analysis for split-phase switching is also presented in detail, without making small ripple approximations. Furthermore, an expression for large ripple flying capacitor energy density utilization is derived, assisting with optimal topology selection and revealing that split-phase operation may be preferable for conversion ratios greater than 6:1. All analysis is verified in simulation, with an additional discrete hardware prototype further validating a complex case of resonant split-phase timing. The analytical results of 17 distinct Dickson variations are recorded, assisting with topology selection and design.

Automated summary

This paper provides a comprehensive review of Dickson-type HSC converters and introduces eight fundamental reduced HSC Dickson structures. It presents analysis and characterization of large signal operating points, capacitor sizing regimes, switching schemes, and maximum allowable power throughput. The analysis is verified through simulation and validated with a hardware prototype.