Reducing stray magnetic field effects using a magnetic field feedback

A magnetic-field sensor comprising:

• main coil circuitry configured to generate a first magnetic-field signal at a first frequency, wherein a reflected signal is generated from a target caused by the first magnetic-field signal;
• a first channel comprising:
• a first magnetoresistance circuitry configured to receive the reflected signal and the first magnetic-field signal;
• and
• a first analog circuitry configured to receive an output signal from the first magnetoresistance circuitry and to provide a first channel output signal;
• a second channel comprising:
• a second magnetoresistance circuitry configured to receive the reflected signal and the first magnetic-field signal;
• and
• a second analog circuitry configured to receive an output signal from the second magnetoresistance circuitry and to provide a second channel output signal;
• a subtractor circuit configured to subtract the second channel output signal from the first channel output signal to form a subtraction signal;
• an adder circuit configured to combine the first channel output signal and the second channel output signal to form a summation signal;
• a first additional analog circuitry configured to receive the subtraction signal and to provide a first digital output signal to processing circuitry and to provide an analog signal to feedback circuitry;
• a second additional analog circuitry configured to receive the summation signal and to provide a second digital output signal to the processing circuitry;
• the feedback circuitry configured to receive the analog signal and to provide a first feedback signal to the first additional analog circuitry and a second feedback signal to secondary coil circuitry;
• the secondary coil circuitry configured to receive the second feedback signal and to generate, based on the second feedback signal, a second magnetic-field signal to reduce the first magnetic-field signal received at the first magnetoresistance circuitry;
• and
• the processing circuitry configured to receive the first and second digital signals and to provide a magnetic-field sensor output signal indicating a position of the target.