Patent ID: 11927650
Assignee: ALLEGRO MICROSYSTEMS, LLC
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. A magnetic field sensor comprising:
magnetoresistance circuitry configured to receive a residual magnetic field including a difference between an applied magnetic field produced by a magnetic source at a first frequency and a feedback magnetic field and produce an electrical output signal;
diagnostic signal generation circuitry configured to generate a diagnostic signal at a second frequency and combine the diagnostic signal with the output signal from the magnetoresistance circuitry to generate a combined signal, wherein the combined signal includes the diagnostic signal and main signal components;
feedback circuitry coupled to the magnetoresistance circuitry and configured to receive the combined signal, wherein the feedback circuitry is configured to produce a feedback signal based on the combined signal;
feedback coil circuitry including a feedback coil configured to receive the feedback signal and operative to generate the feedback magnetic field; and
diagnostic processing circuitry configured to extract the diagnostic signal from the combined signal and produce an error indication when the extracted diagnostic signal is outside of a normal-operation range.