Researchers from the Fraunhofer Institute have integrated current and temperature sensors, 600 V-class power transistors, freewheeling diodes, and gate drivers onto a gallium nitride (GaN)-based semiconductor chip. The new circuit measures 4 x 3 mm and enables high switching frequencies and a high power density, while providing fast and accurate condition monitoring, according to the institute.
Temperature and current sensors were previously external to the GaN chip. The new integrated sensors allow for more direct measurements, resulting in faster, more accurate, and feedback-free monitoring. To integrate the sensors, the researchers used gallium nitride deposited on a silicon substrate, which allows current to flow parallel to the chip’s surface and to have connections placed at the top of the chip.
The research is part of Fraunhofer’s GaNIAL (integrated and efficient power electronics based on gallium nitride) research initiative.
“By additionally integrating sensors on the GaN chip, we have succeeded in significantly enhancing the functionality of our GaN technology for power electronics,” said Patrick Waltereit, Project Manager of GaNIAL and Deputy Head of the Power Electronics Business Unit at Fraunhofer.
“The monolithic integration of the GaN power electronics with sensors and control circuit saves space on the chip surface, reduces the outlay on assembly, and improves reliability. For applications that require lots of very small, efficient systems to be installed in limited space, such as in electromobility, this is crucial,” said Stefan Mönch, a researcher in the Power Electronics Business Unit at Fraunhofer.