This paper presents the development and performance evaluation of an 11 kW single-stage, three-phase AC-DC Onboard Charger (OBC) based on a Matrix Converter topology, utilizing bidirectional EliteSiC FET technology. The Matrix Converter architecture eliminates the need for traditional boost inductors and bulk capacitors typically found in conventional two-stage topologies that incorporate a PFC front end and isolated DC-DC power stage. A phase-shift control strategy is implemented to meet the wide battery charging voltage range of 250 V to 800 V, accommodating input voltages from 400 V to 480 V three-phase AC and split-phase 240 V. The resulting OBC hardware achieves a peak efficiency of 97.5% and a power density of 3.1 kW/L.

To further enhance power density and efficiency, onsemi is developing advanced bidirectional switches based on SiC JFET dies and Vertical GaN-based enhancement-mode JFETs (eJFETs). This paper presents PLECS-based simulation results comparing the performance of 1200 V SiC FETs, SiC JFETs, and Vertical GaN eJFETs operating at 140 kHz. Additionally, we explore the potential of increasing switching frequencies to 400 kHz and beyond into the MHz range using Vertical GaN technology, highlighting its advantages for next-generation high-performance OBC systems.