IN Brief:
- Infineon and Visteon-Shinry Power Electronics are jointly developing a single-stage onboard electric vehicle charger.
- Monolithic GaN bidirectional switches support an architecture that eliminates the large intermediate DC-link capacitors used in conventional two-stage designs.
- The proposed charger targets 22 kW three-phase and 19.2 kW single-phase operation, with automotive validation continuing.
Infineon Technologies is collaborating with Visteon-Shinry Power Electronics (VSPE) to develop a single-stage onboard charger for electric vehicles using monolithic gallium nitride bidirectional switches.
The development combines Infineon's semiconductor technology with converter hardware, control algorithms, and system integration expertise from VSPE, a joint venture between Visteon Corporation and SHINRY Technologies. The companies are targeting a more compact charging architecture with fewer power conversion components than conventional two-stage designs.
Announced at electronica 2026 in Munich, the proposed charger supports 22 kW three-phase and 19.2 kW single-phase AC charging. Bidirectional vehicle-to-everything functionality is also planned, allowing electrical energy to flow between the vehicle battery and compatible external systems.
Conventional onboard chargers generally perform two principal power conversion functions. An AC-to-DC stage converts incoming electricity and controls the current drawn from the supply, while a subsequent DC-to-DC stage regulates the energy delivered to the vehicle battery.
The first stage commonly incorporates power factor correction to shape the input current in relation to the AC voltage. The second provides the required voltage conversion and, in typical isolated architectures, galvanic separation between the incoming electrical supply and the vehicle's high-voltage battery circuit.
A substantial intermediate DC-link capacitor connects the two stages, helping manage variations in energy transfer and stabilise the voltage supplied to the downstream converter. These capacitors occupy space and contribute to the component count, mechanical construction, and thermal design of the charger.
VSPE's proposed single-stage topology combines functions normally performed by separate converter stages and eliminates the large intermediate DC-link capacitor. The architecture is intended to reduce packaging volume, component requirements, and the complexity associated with a conventional two-stage arrangement.
Removing that energy buffer changes the control problem. The instantaneous power available from an AC supply varies throughout its cycle, while battery charging requires carefully regulated current and voltage. The converter must therefore manage input current, power transfer, and output regulation without relying on the same substantial intermediate energy storage.
These requirements become more demanding when a charger must support different AC supply configurations and bidirectional operation. The control system must coordinate switching behaviour across changing input conditions and battery voltages while maintaining the electrical characteristics required at the supply connection.
Infineon's monolithic GaN bidirectional switches provide the semiconductor functions required by the architecture. Unlike conventional unidirectional power switches, the devices combine bidirectional voltage blocking and current conduction within one semiconductor structure.
Such devices can replace arrangements that otherwise require multiple discrete transistors to implement the necessary current paths and voltage blocking characteristics. Reducing the number of packages and associated connections can simplify the power stage, although the surrounding circuit still needs appropriate gate driving, protection, sensing, and control.
Gallium nitride supports high-frequency switching, allowing converter designs to investigate smaller magnetic components and increased power density. The final benefit depends on switching losses, passive component design, thermal management, and the electrical performance of the complete circuit rather than the semiconductor material alone.
Fast switching also creates layout challenges. Parasitic inductance and capacitance can produce unwanted voltage overshoot, ringing, and electromagnetic emissions, particularly when large currents are commutated rapidly. Gate-drive design, component placement, grounding, and the geometry of power-current loops consequently influence reliable operation.
The proposed architecture must also satisfy automotive electrical isolation and protection requirements. Eliminating a conventional DC-link stage does not remove the need to manage isolation, leakage currents, fault conditions, or electromagnetic compatibility within the complete charger.
Bidirectional operation introduces additional requirements because the vehicle must be capable of transferring energy to suitable external equipment or infrastructure as well as receiving energy during charging. The power electronics must support both directions of energy flow, while the control system coordinates operating modes with the battery management system and external connection.
The companies identify vehicle-to-everything capability as part of the development. However, they have not specified the supported grid-interconnection arrangements, communication protocols, or individual vehicle-to-home, vehicle-to-load, and vehicle-to-grid operating modes.
VSPE is developing the converter architecture and control functions while Infineon supplies the bidirectional GaN switching technology. The collaboration combines the semiconductor's electrical capabilities with a system architecture intended to exploit them, rather than substituting a new power transistor into an otherwise unchanged charger.
The proposed 22 kW and 19.2 kW charging ratings establish the intended capability of the system across three-phase and single-phase supplies. The partners have not disclosed measured conversion efficiency, charger dimensions, power density, operating switching frequency, or comparative reliability results for the completed architecture.
Infineon has published broader technical guidance describing the potential of single-stage GaN charging topologies, but performance figures associated with those reference examples cannot be assumed to apply to the VSPE development. Its actual performance will depend on the final circuit design, operating conditions, and validation results.
Mark Sun, chief technology officer at SHINRY, confirmed that the joint research and development team is working to validate the architecture against automotive reliability requirements. The companies have not announced a production qualification milestone or commercial introduction date.
Further development will need to establish efficiency, thermal behaviour, electromagnetic compatibility, electrical safety, and performance across the intended charging and energy export modes. The collaboration has defined the proposed converter architecture and charging ratings, but its production readiness remains dependent on completion of that validation work.
