By ATN Editorial Team
Summary: The EU-funded HiPower 5.0 project, overseen by Fraunhofer IZM, is developing a 22 kW GaN on-board charger that occupies just four litres — roughly one-third the size of today’s twelve-litre market average. The 40-plus partner consortium uses bidirectional GaN switches from Infineon to halve the semiconductor count and shrink the cooling envelope inside electric vehicles.
Key engineering takeaway: A monolithically integrated bidirectional gallium nitride (GaN) device routes current in both directions, so a single component does the work of two conventional silicon switches. Combined with circuit-board-embedded passives and tighter system-level packaging, the GaN on-board charger reaches the 22 kW class in a four-litre volume that conventional silicon designs cannot match.
Why it matters: A smaller, more efficient GaN on-board charger reduces thermal load, lowers vehicle mass and frees packaging space inside the EV, opening 22 kW AC charging to vehicle classes where it was previously impractical. HiPower 5.0 is also the most visible attempt yet to keep the wide-bandgap automotive supply chain — semiconductors, packaging and integration — on European soil.
Why A Compact GaN On-Board Charger Matters For EV Efficiency
Mobility is key if the European Union wants to reach its own climate goals: Traffic accounts for 28% of the climate emissions in the EU, with a full 80% due to road traffic. Electric vehicles could be a game changer. The on-board chargers or OBCs built into electric vehicles convert the electricity from the grid into energy suitable for the batteries. As chargers become more powerful, their efficiency, heat management, and size become increasingly challenging. Conventional silicon-based technology leaves only little room for further optimization. Energy losses mean more heat, which in turn means more need for cooling. More cooling requires larger systems, meaning the most powerful OBCs are not suitable for all vehicle sizes. Simpler systems with fewer components promise greater efficiency, lower costs, and wider market acceptance.
This is why the HiPower 5.0 consortium, overseen by the Fraunhofer Institute for Reliability and Microintegration IZM, has dedicated its work on the automotive use case to producing a powerful 22 kW OBC with a total size of only four liters — far smaller than the current market average of twelve liters.
Bidirectional GaN Switches Cut The Semiconductor Count
The innovation revolves around novel gallium nitride (GaN) semiconductors provided by Infineon. These monolithically integrated, bidirectional GaN switches enable more efficient conversion in a smaller package since they are designed to control the flow of electricity in both directions. Thus, a single component does the work of what were originally two separate semiconductors, paving the way for new technological opportunities. Circuit designs now become possible that would have required costly compromises with more conventional components.
However, the material alone is not the only critical factor, but also the way in which all the components in the vehicle work together. This is where the many years of experience with packaging and system development at Fraunhofer IZM come into play: The components are not optimized individually. Rather, design decisions are always governed by the system as a whole: Several electronic components are embedded directly into the circuit boards, which shortens critical paths, reduces potential losses, and saves precious space overall.
A first working unit demonstrating the potential of the innovative technical approaches was a compact and powerful 22kW on-board charger for electric cars. Fraunhofer IZM first exhibited the charger, which was still without bidirectional GaN components, at the 2024 PCIM Europe.
The goal of the HiPower 5.0 consortium is to harness the advantages of modern GaN and wide-bandgap semiconductors in market-ready products within a fully European value chain. In addition to the automotive sector, the consortium is also addressing applications in the marine shipping industry. The HiPower 5.0 project brings together partners from ten European nations, including two OEMs, 21 tier-1 and tier-2 suppliers, six specialists for power electronics, ten universities, and seven research institutions. From August 2025 to June 2028, they are working on six use cases, supported by 33.7 million Euro in funding from the EU and its member states. The German Federal Ministry of Research, Technology, and Space is contributing 5.74 million Euro and the Free State of Saxony is contributing 0.12 million Euro.
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