A Hall sensor microsystem with integrated voltage and current references for continuous sensitivity calibration

Abstract

This paper presents a Hall sensor microsystem with a current output and sensitivity calibration targeting low drift (<;50ppm/°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 0.35μm CMOS technology, occupying an area of 11.55mm2. The measurements of the calibrated system show 80ppm/°C on average and 30ppm/°C best-case sensitivity drift over a temperature range from -40°C to 85°C. Compared to the state of the art, the fully integrated system for sensitivity calibration adds no more than 18ppm/°C on average and 30ppm/°C in the worst case for the additional integration of one voltage and one current reference.