Achieving the highest performance in power converters requires mastery of emerging technologies such as CMOS microelectronic integration, GaN technologies, and ultra-wide bandgap materials (e.g., diamond). This research area aims to design and characterize new Gate Driver circuit architectures in CMOS technology for driving GaN and SiC transistors and modules, as well as to design the next generation of integrated functions and power components using GaN and diamond technologies.

Our group does not operate an in-house fabrication facility but has full access to state-of-the-art design, simulation, and manufacturing tools through our partnerships and expertise. This mastery enables us to develop functionalities that cannot be achieved through discrete component assemblies and to prototype the next generation of power switching components and cells.

Our expertise allows us to design these functions at the sub-micrometer and microampere scale and implement and demonstrate them in power switching cells operating at the macroscopic scale, handling several hundred amperes and hundreds of volts.

CMOS Gate Driver circuits for GaN and SiC power components:
Optimizing the switching behavior of wide bandgap transistors is a real challenge. High switching speeds reduce switching losses but generate electromagnetic interference (EMI) at high amplitudes and frequencies. We have proposed active switching control strategies, notably through feedback from the power stage to the control stage, in order to locally reduce the dV/dt during switching transients, improving the EMI/losses trade-off.

This is particularly challenging with medium-voltage GaN transistors, which can switch 400 V within a few nanoseconds. CMOS integration enables an analog bandwidth close to 10 GHz, making it possible—through optimization and analog amplification—to selectively reduce the gate current during the dV/dt phase via feedback control.

Thanks to the LabCom SEMA partnership, other integrated circuits using NXP’s SmartMOS technology have been developed to optimize and adaptively control the dead time of SiC switching cells or, in connection with Operation 4 of our group, to improve detection and protection against extreme short-circuit conditions.

Diamond power electronics, GaN monolithic integration, and beyond:
Wide bandgap devices such as SiC and GaN have been commercially available for many years, driving major breakthroughs in converter performance. However, ultra-wide bandgap materials like Ga₂O₃, h-BN, AlN, ZnOx, and diamond are identified as the next technological leap. Diamond is regarded as the ultimate material due to its unique properties.

This upstream activity is mainly driven by laboratories and start-ups with whom we closely collaborate (Institut Néel, DIAMFAB, University of Cambridge, University of Cádiz, Arizona State University, AIST). Our contributions have been recognized through our involvement in two European projects, one PEPR program (Frenchdiam), two ANR projects (including one coordination), and the “Etoiles de l’Europe” award for the GreenDiamond project, along with several other European project submissions during the period.

Through our close partnership with Institut Néel and the start-up DIAMFAB, significant advances have been made toward achieving the target of 1 kV and 1 A devices.

In addition, monolithic integration drastically reduces parasitic interconnections between the power components and their local control circuits. Lateral GaN technology enables such integration. We are currently designing and developing integrated control functions in GaN-on-SOI technology, through Europractice and IMEC technology (Belgium).