Demystifying Capacitive Isolation in High-efficiency dc-dc Converters by Cassiano Rech

Abstract: Capacitive isolation has emerged as a powerful alternative to magnetic isolation in modern DC–DC converters, offering compelling advantages in efficiency, power density, and cost, while also providing safety benefits. In this sense, this webinar demystifies capacitive isolation by bridging fundamental principles with practical, experimentally validated converter designs. The webinar will explore how capacitor-based isolation can simultaneously enable high-efficiency power transfer and intrinsic touch-current limitation, addressing stringent safety standards without relying on bulky transformers. Key concepts such as resonant switched-capacitor operation, partial power processing, and symmetrical DC-bus architectures are discussed in the context of real-world converter topologies. The webinar will highlight measurable benefits over conventional isolated solutions, such as reduced semiconductor count, smaller volume, simplified control, and peak efficiencies close to 98%. Comparisons with LLC and transformer-based architectures clearly highlight the strengths of capacitive isolation, as well as the design considerations required for its effective implementation. Furthermore, it will be demonstrated how capacitive isolation topologies can be employed in the design of partial power processing converters, achieving efficiencies near 99.6% and power densities around 12 kW/L. Targeted at power electronics engineers, this webinar will provide design insights, clarify safety misconceptions, and demonstrate how capacitive isolation can unlock the next generation of compact, efficient, and safer DC–DC converters for automotive and industrial applications.