COMPENSATION OF THE THE TEMPERATURE-DEPENDENT OFFSET DRIFT OF A HALL SENSOR

摘要

We present a method to cancel the offset of a Hall sensor and compensate its temperature-dependent drift. We adapt and improve a compensation technique based on a correction using the input voltage. A more accurate compensation far the temperature drift is obtained by an offset calibration at two different temperatures. To decrease the calibration time, we propose a procedure for fast heating of the sensor, It consists of forcing a current pulse through a pn junction of the sensor. Since the resistance of a forward-biased diode is small, this principle is compatible with low-voltage applications. After correction, the resulting offset is less than two percent of the initial offset over the temperature range -10 to +-60 degrees C. The corresponding residual equivalent offset is lower than 250 mu T. [References: 5]