A fully integrated Hall Sensor Analog Front End with Analog closed loop self-calibration

This paper presents a fully integrated Hall sensor Analog Front End with an analog, closed loop, selfcalibration circuit, able to detect current values in the range of $\pm 120 \mathrm{~A}$ with a power supply voltage of 5 V. This calibration is performed using an integrated coil where a reference current flows. The proposed system can separate and extract the magnetic field generated by the reference current, compensating the sensitivity variation of the Hall sensors in temperature and mechanical stress, using an analog closed loop. Thanks to this fully integrated analog technique, experiments on fabricated chips have reported very low sensitivity drifts, with measured values of $100 \mathrm{ppm} /{ }^{\circ} \mathrm{C}$ and $\pm 0.3 \%$ variations over temperature and mechanical stress, respectively.