Sensor Resistance Based Sensitivity Temperature Drift Tracking of Integrated 3D Hall Sensors

The magnetic sensitivity of voltage controlled Hall sensors changes up to $\pm 40\%$ in the temperature range from −40°C to 125°C, resulting in large measurement errors. To track the temperature induced sensitivity variation, state of the art systems use additional temperature sensors and/or on-chip calibration coils. This paper presents a method to track the magnetic sensitivity temperature drift of a Hall sensor based on its own resistance. The proposed method results in a tracking accuracy of $\pm$ 6% for Bx, By and $\pm$ 3% for Bz in the temperature range from −40°C to 125°C. Providing a magnetic sensitivity to bias current transfer function further enhances the tracking accuracy to $\leq 1\%$. It requires no additional integrated coils or temperature sensors.