Ultra-Wideband Surface Current Sensor Topology for Wide-Bandgap Power Electronics Applications

Through the development of wide-bandgap semiconductor devices, power electronics systems are enabled to operate at higher switching frequencies, requiring minimally invasive current sensing solutions to allow real-time monitoring and control of the system. The majority of current sensors available on a commercial level, however, do not possess many of the properties needed for high-frequency wide-bandgap converters (physical dimensions, bandwidth, noise immunity, isolation, and circuit invasion). While clamp-shaped current transducers (such as current transformers and non-invasive toroidal/helical Hall-effect or Rogowski coil sensors) are more suitable for traditional vertical power modules and switches, they may not be appropriate for lateral wide-bandgap power devices with very tight layouts and ultra-high switching speeds. Surface-mounted Rogowski coils or lateral current sensors would typically be more appropriate for this application, allowing a seamless design integration that is required for compact high-frequency power electronics. In this paper, a Rogowski coil-based embedded lateral current sensor is proposed, manufactured, and tested to demonstrate its ability to measure the switching current of lateral power switches, also known as on-trace current sensing.