A DC to 25 MHz Current Sensing Interface using Hall-effect Sensor

Researchers in Stanford University's EXtreme Environment Microsystems Laboratory (XLab) working in collaboration with the University of Arkansas' Mixed-Signal Computer-Aided Design (MSCAD) Laboratory developed a Hall-effect sensor design that detects ultra fast changes in the magnetic field, and provides a non-invasive fast current detection solution that can operate from DC to 25 MHz and beyond. The current sensing system uses high-bandwidth gallium nitride (GaN) Hall-effect sensors and a fast readout interface. A 2-way current spinning technique minimizes offset at DC levels, while a high pass filter eliminates sensor offset at high frequencies. Two sensors and signal paths make it possible to take advantage of the full sensor bandwidth and detect fast changes in the magnetic field. The XLab/MSCAD non-invasive fast current detection solution is ideal for turbines, motors, converters, inverters, and engine systems that operate at DC / low frequency to high frequency in the 10s of MHz and beyond.

Stage of Development - Proof of concept prototype
XLab/MSCAD prototype detected DC to 25MHz (significantly higher than anything on the market). The group continues refining the circuits to build a single chip with sensor and developing machine learning algorithms to detect faults in motor systems.