Highly-Efficient, Isolated Multi-MHz GaN-based DC-DC Converters with Active Diode Rectification

• Applicants: Professor Dr.-Ing. Ingmar Kallfass; Professor Dr.-Ing. Martin März
• Subject Area: Electrical Energy Systems, Power Management, Power Electronics, Electrical Machines and Drives ; Electronic Semiconductors, Components and Circuits, Integrated Systems, Sensor Technology, Theoretical Electrical Engineering
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 546275218

Gallium Nitride (GaN)-based converters operating at switching frequencies in the radio frequency (RF) range between 3 and 30 MHz promise significantly increased power densities, reduced transient response time, and enable the development of new fields of application, such as in the area of capacitive power transmission. This project addresses the two central hurdles on the way to such high switching frequencies, the lack of suitable solutions for highly integrated inductive components in this frequency range and the lack of highly efficient solutions for secondary-side rectification. The project aims to investigate the extensive optimization of GaN-based high-frequency (several MHz), isolated DC-DC converters with monolithic integrated, active diode rectifier circuits on the secondary side. By a comprehensive mathematical analysis of the converter stage combined with an optimized magnetic design, a multi-domain optimization of the whole converter in the thermal and electrical domain is targeted. The targeted design methodology is completely scalable and parametrizable to transfer it to other applications and technologies. By a monolithic integration of an GaN active diode, a self-controlled rectifier stage for MHz frequencies is to be investigated in terms of efficiency, power density, scalability and transferability to other appli-cations. The research hypothesis is that by a comprehensive analysis of the whole GaN-based converter including the magnetic and thermal design and the derivation of the transistor level requirements for a monolithic GaN-based integrated active diode, a considerably improved efficiency-times-power-density figure-of-merit will be reached.

• DFG Programme: Priority Programmes
• Subproject of: SPP 2312: Energy Efficient Power Electronics "GaNius"