Coil-calibrated magnetic sensor

A sensor, comprising:

• a first sensing element and a first calibration coil that is disposed adjacent to the first sensing element, the first sensing element being configured to generate a first signal at least in response to a primary magnetic field and a first calibration magnetic field that is generated by the first calibration coil;
• a second sensing element and a second calibration coil that is disposed adjacent to the second sensing element, the second sensing element being configured to generate a second signal at least in response to the primary magnetic field and a second calibration magnetic field that is generated by the second calibration coil;
• a first modulator that is configured to modulate a signal used to drive the first calibration coil and the second calibration coil based on a signal M;
• a first summation element that is configured to add the second signal to the first signal to at least in part generate a third signal that is indicative of a sum of the first signal and the second signal;
• and
• a feedback circuit that is configured to execute a correlation function that correlates the signal M with the signal used to drive the first calibration coil and adjust a bias of the first sensing element and the second sensing element based on a value of the correlation function,
• wherein the first calibration magnetic field and the second calibration magnetic field have a same direction, and
• wherein the primary magnetic field has opposite directions at respective locations of the first sensing element and the second sensing element.

A sensor, comprising:

• a first sensing element and a first calibration coil that is disposed adjacent to the first sensing element, the first sensing element being configured to generate a first signal at least in response to a primary magnetic field and a first calibration magnetic field that is generated by the first calibration coil;
• a second sensing element and a second calibration coil that is disposed adjacent to the second sensing element, the second sensing element being configured to generate a second signal at least in response to the primary magnetic field and a second calibration magnetic field that is generated by the second calibration coil;
• a first modulator that is configured to modulate a signal used to drive the first calibration coil and the second calibration coil based on a signal M;
• a first summation element that is configured to subtract the second signal from the first signal to at least in part generate a third signal, the third signal being indicative of a difference between the first signal and the second signal;
• and
• a feedback circuit that is configured to execute a correlation function that correlates the signal M with the signal used to drive the first calibration coil and adjust a gain of the first signal and the second signal based on a value of the correlation function,
• wherein the first calibration magnetic field and the second calibration magnetic field have different directions, and
• wherein the primary magnetic field has opposite directions at respective locations of the first sensing element and the second sensing element.