Project Details
Projekt
High Frequency Switching Power Converters based on AlN-based Power Transistors
Subject Area
Electronic Semiconductors, Components and Circuits, Integrated Systems, Sensor Technology, Theoretical Electrical Engineering
Term
since 2021
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 462718666
Galliumnitride-based lateral transistors enable low switching losses and high switching speeds in power converters up to 600 V. However, the intrinsic limits of this material can still not be reached as the achievable blocking voltage, current density and speed are limited by material and system level constraints. The aim of this project is to overcome these limitations and demonstrate efficient converters with very high switching frequencies - MHz at 400 V for kW power and GHz at 40 V. This project is a follow-up project. In the first project period, the immunity to backgating, and thus suitability for monolithic integration even at higher voltages, of AlN-on-SiC epitaxy was demonstrated. Furthermore, sensor and control concepts such as a drain bias sensor and active dead time control were developed and implemented. These make it possible to minimize the time of the intrinsic reverse conduction, which is particularly lossy in GaN HEMTs, and thus increase efficiency, especially at high frequencies. In addition, monolithic integrated drivers were developed, with which a 50 W converter IC with a switching frequency of 200 MHz was realized. Based on these results, the AlN-on-SiC epitaxy, which currently shows strong dispersion effects, will be further optimized. The sensor and control concepts as well as the drivers will be further developed, with a particular focus on the speed of these components. For this purpose, a combination of monolithic and hybrid integration will be used so that parasitic inductances and runtimes can be minimized. These further developments are then demonstrated in an isolated 4 kW DC-DC converter consisting of an LLC converter and synchronous rectifier, a 48 V, 200 MHz PoL converter and a 1 GHz buck converter.
DFG Programme
Priority Programmes
Subproject of
SPP 2312:
Energy Efficient Power Electronics "GaNius"
