GaN Technology Comes to Electric Cars: More Efficiency, Less Bulk, Ideal for City Cars

Europe takes a step forward in electric vehicle charging as part of the HiPower 5.0 project, an initiative funded by the European Union involving 45 partners from ten countries aimed at completely rethinking the charging systems integrated into vehicles. At the heart of the development is the Fraunhofer Institute for Reliability and Microintegration IZM, which is working on a new 22 kW on-board charger (OBC) that occupies just 4 liters of volume, compared to about 12 liters required by traditional systems today.

The OBC is one of the key components of EVs, as it converts energy from the electric grid into power compatible with the battery. However, the increase in charging performance has imposed increasingly apparent limits on silicon-based systems, especially concerning energy efficiency, thermal dissipation, and bulk. Energy losses produce more heat, which requires larger cooling systems, leading to bulkier devices that are difficult to integrate into compact cars.

"Conventional silicon-based technology leaves little room for further optimizations. Energy losses mean more heat, which in turn increases the need for cooling. More efficient cooling requires larger systems, which means that more powerful OBCs are not suitable for all vehicle sizes," explained experts from Fraunhofer.

To overcome these constraints, the European consortium has chosen new bidirectional gallium nitride (GaN) semiconductors developed by Infineon. This technology allows managing electric flow in both directions with a single component, replacing two separate semiconductors. The result translates into simpler electronic architectures, fewer components, lower losses, and reduced costs.

The advantage lies not only in the material used but in the entire system design. Fraunhofer IZM aims for a comprehensive integration strategy that includes embedding electronic components directly into printed circuits, a solution that reduces the length of connections, optimizes efficiency, and frees up additional space. This approach enables simultaneous advancements in size, reliability, and performance.

A first prototype of a compact 22 kW charger was already presented at PCIM Europe 2024, but without the use of bidirectional GaN components. With HiPower 5.0, the new advancement consists precisely in the union of structural miniaturization and next-generation semiconductors.

The program, active from August 2025 to June 2028, has a total funding of 33.7 million euros, with 5.74 million euros allocated by the German Federal Ministry of Education and Research and an additional 120,000 euros from Saxony. In addition to automotive, the project also assesses applications in the naval sector, aiming to create a complete European supply chain for semiconductors and power electronics for the industrial sector.