Fast Electronic Fuse built with SiC MOSFETs, Sigma-Delta-based Current Sensing and FPGA-based Digital Signal Processing

SiC MOSFETs are especially good for use as switches in electronic fuses for higher power applications. They can conduct current with low loss and can also turn off very quickly. The utilization of a shunt and a sigma-delta modulator for current sensing allows easy galvanic isolation of logic and power domains. FPGA-based digital signal processing is fast and insensitive to EMI. It can detect and break overcurrents caused by a short circuit in a very short time. User-adjustable $I^{2} t$ models run in parallel to protect the wires and the electronic fuse itself. The parasitic inductance of the shunt and the bonding inductance of the SiC MOSFET are made use of to reduce the filter delay. Realistic examples are employed to demonstrate that with a suitable bitstream filtering implementation the response time is significantly lower than the settling time of regular Sinc³ filters.