A RISC-V-based System on Chip for High-Speed Control in Safety-Critical 650 V GaN-Applications

Abstract:
In power electronics applications, Gallium Nitride (GaN)-based transistors generally offer benefits in efficiency and switching speed, but come at the cost of harder controllability and thus more complex control circuits. As a contribution towards easier and safer control for GaN-devices, we present a new system-on-chip (SoC) specifically dedicated to the control of GaN-based power modules. The main processing unit is compliant with the RISC-V specification and implements the RV32IMC instruction set. Major parts of a control algorithm may be performed by peripheral modules that reduce workload on the processor and enable low-latency reactions towards safety-critical events in the GaN-circuit. The output is generated by a PWM-unit that supports sub-nanosecond resolution. The processor achieves a benchmark score of 2.03 CoreMark per MHz. The SoC reacts to threshold violations on measurement inputs within 25 ns. Future steps will involve expanding the SoC with more safety features and the coupling of several SoCs for multiphase synchronization.