Circuits and methods for generating a diagnostic mode of operation in a magnetic field sensor
First Claim
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1. A magnetic field sensor, comprising:
- at least two magnetic field sensing elements; and
a switching circuit coupled to the at least two magnetic field sensing elements, wherein the switching circuit is configured to couple the at least two magnetic field sensing elements into a normal mode configuration when the magnetic field sensor is in a normal mode of operation, and wherein the switching circuit is configured to couple the at least two magnetic field sensing elements into a diagnostic mode configuration when the magnetic field sensor is in a diagnostic mode of operation, wherein the at least two magnetic field sensing elements are configured to generate a magnetic field signal comprising;
a measured-magnetic-field-responsive signal portion responsive to an external magnetic field and substantially unresponsive to a diagnostic magnetic field when coupled in the normal mode configuration; and
a diagnostic-magnetic-field-responsive signal portion responsive to the diagnostic magnetic field and substantially unresponsive to the external magnetic field when coupled in the diagnostic mode configuration,wherein the magnetic field sensor is operable to generate a diagnostic output signal from the magnetic field sensor when in the diagnostic mode of operation, wherein the diagnostic output signal is capable to indicating results of a self-test of the at least two magnetic field sensing elements and a self-test of processing circuits coupled to the at least two magnetic field sensing elements.
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Abstract
A magnetic field sensor includes a diagnostic circuit that allows a self-test of most of, or all of, the circuitry of the magnetic field sensor, including a self-test of a magnetic field sensing element used within the magnetic field sensor. The magnetic field sensor can generate a diagnostic magnetic field to which the magnetic field sensor is responsive.
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Citations
31 Claims
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1. A magnetic field sensor, comprising:
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at least two magnetic field sensing elements; and a switching circuit coupled to the at least two magnetic field sensing elements, wherein the switching circuit is configured to couple the at least two magnetic field sensing elements into a normal mode configuration when the magnetic field sensor is in a normal mode of operation, and wherein the switching circuit is configured to couple the at least two magnetic field sensing elements into a diagnostic mode configuration when the magnetic field sensor is in a diagnostic mode of operation, wherein the at least two magnetic field sensing elements are configured to generate a magnetic field signal comprising; a measured-magnetic-field-responsive signal portion responsive to an external magnetic field and substantially unresponsive to a diagnostic magnetic field when coupled in the normal mode configuration; and a diagnostic-magnetic-field-responsive signal portion responsive to the diagnostic magnetic field and substantially unresponsive to the external magnetic field when coupled in the diagnostic mode configuration, wherein the magnetic field sensor is operable to generate a diagnostic output signal from the magnetic field sensor when in the diagnostic mode of operation, wherein the diagnostic output signal is capable to indicating results of a self-test of the at least two magnetic field sensing elements and a self-test of processing circuits coupled to the at least two magnetic field sensing elements. - View Dependent Claims (2, 3, 4, 5, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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6. The magnetic field sensor of claim , wherein the magnetic field sensor is configured to sense a position of a gear shift lever when the at least two magnetic field sensing elements are coupled in the normal mode configuration.
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21. A method of generating a self-test of a magnetic field sensor, comprising:
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coupling at least two magnetic field sensing elements into a normal mode configuration when the magnetic field sensor is in a normal mode of operation, coupling the at least two magnetic field sensing elements into a diagnostic mode configuration when the magnetic field sensor is in a diagnostic mode of operation, wherein the at least two magnetic field sensing elements are configured to generate a magnetic field signal comprising; a measured-magnetic-field-responsive signal portion responsive to an external magnetic field and substantially unresponsive to a diagnostic magnetic field when coupled in the normal mode configuration; and a diagnostic-magnetic-field-responsive signal portion responsive to the diagnostic magnetic field and substantially unresponsive to the external magnetic field when coupled in the diagnostic mode configuration, and generating a diagnostic output signal from the magnetic field sensor when in the diagnostic mode of operation, wherein the diagnostic output signal is capable of indicating results of a self-test of the at least two magnetic field sensing elements and a self-test of processing circuits coupled to the at least two magnetic field sensing elements. - View Dependent Claims (22, 23, 24, 25, 26, 27, 28, 29, 30, 31)
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Specification