Magnetometer with Dual Purpose Reset and Calibration Coil

摘要

The present invention discloses a magnetic field sensing device that utilizes a single coil for calibrating the response of the sensor to compensate for temperature dependent sensitivity drift and also for resetting the magnetic field sensor in order to eliminate hysteresis. The single coil configuration is advantageous since it reduces the size of the sensor chip by decreasing the number of contact pads on the chip and also because it wastes less space, which permits an increase in the density of the magnetoresistive elements on the sensor chip.

主权项

1. A magnetic field sensor, comprising at least one magnetoresistive sensor element and an electric conductor in the proximity of the magnetoresistive sensor element in order to generate a magnetic field, wherein the coercivity of the magnetoresistive sensor element is equal to the magnetic offset field of the magnetoresistive sensor element, wherein an electric current applied to the electric conductor generates the magnetic biasing field parallel to a sensing axis of the magnetoresistive sensor element, wherein a first electric current is applied to reset the magnetic field sensor, and a second current is applied to calibrate the magnetic field sensor.