A Hall sensor microsystem with integrated voltage and current references for continuous sensitivity calibration
This paper presents a Hall sensor microsystem output and sensitivity calibration targeting low drift (<50ppm/degrees C). The main system novelty is in a circuit-level solution using dedicated on-chip voltage and current references for a continuous measurement and calibration of the sensitivity. The system is fabricated in a 0.35 mu m CMOS technology, occupying an area of 11.55mm(2). The measurements of the calibrated system show 80ppm/degrees C on average and 30ppm/degrees C best-case sensitivity drift over a temperature range from -40 degrees C to 85 degrees C. Compared to the state of the art, the fully integrated system for sensitivity calibration adds no more than 18ppm/degrees C on average and 30ppm/degrees C in the worst case for the additional integration of one voltage and one current reference.