SiC Power Module Design for High Bandwidth Integrated Current Sensing using a Magnetoresistive Point Field Detector

Past work has demonstrated that Giant Magnetoresistive (GMR) point field detector (PFD)-based current sensors can be integrated into silicon power modules to achieve compact and galvanically-isolated current sensing. This paper presents a design methodology for SiC power modules to enable GMR PFD-based integrated current sensing with high bandwidth that is appropriate for wide-bandgap (WBG) applications. The latest power module interconnect technologies including ribbon and leadframe interconnects can be configured using magnetic field shaping techniques to achieve high bandwidth during current conduction. A holistic design approach to the interconnects, terminals as well as the baseplate is developed to reduce the skin and proximity effects in the confined environment of a SiC power module. This reduction of eddy currents helps to shape the magnetic fields for AC current sensing up to tens of kilohertz. A power module design is experimentally tested that demonstrates high-bandwidth current sensing using an integrated GMR PFD.