Circuits and Methods for Generating a Self-Test of a Magnetic Field Sensor

摘要

A magnetic field sensor includes built in self-test circuits that allow a self-test of most of, or all of, the circuitry of the magnetic field sensor, including self-test of a magnetic field sensing element used within the magnetic field sensor, while the magnetic field sensor is functioning in normal operation.

主权项

1. A magnetic field sensor comprising:
a magnetic field sensing element supported by a substrate, wherein the magnetic field sensing element is configured to generate a self-test signal responsive to a pulsing self-test magnetic field during one or more self-test time periods; a self-test circuit supported by the substrate, the self-test circuit comprising:
a self-test current conductor proximate to the magnetic field sensing element, the self-test current conductor for carrying a self-test current to generate the self-test magnetic field;a processing circuit coupled to receive a signal representative of the self-test signal; anda diagnostic request processor configured to control the self-test current to be on or off in response to a diagnostic input signal received by the diagnostic request processor or to be indicative of a self-test during one or more time periods in response to a control signal generated by the diagnostic request processor.