A Review of Emerging Trends of GaN Power Semiconductor Applications in Onboard Chargers

As electric vehicles (EVs) continue to gain pace internationally, the demand for efficient, compact and high-power charging options has grown. While fast charging is largely performed by off-board DC chargers, the growth of battery capacities and customer expectations is prompting increasing interest in high-performance on-board chargers (OBCs). This paper presents a complete examination of gallium nitride (GaN)-based bidirectional OBCs running at 400 and 800 V, which are essential voltage levels in recent EV platforms. Various GaN-based power conversion topologies are examined in terms of conduction and switching losses, power density, soft-switching capabilities, thermal management, electromagnetic interference (EMI), power quality and system reliability. This paper also addresses the availability and growth of commercial GaN power modules, progress in GaN device technology and alignment with important industry standards and application-specific criteria. By identifying gaps and new research possibilities, this analysis seeks to enable the design of next-generation OBCs that boost system efficiency, minimize charging time and satisfy the expanding demands of the EV ecosystem.