# US 10,480,957 B2 · Magnetic field sensor to detect direction of angular rotation of a rotating magnetic structure, speed of the rotating magnetic structure or fault > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,480,957 B2 - Document ID: US10480957B2 - Status: Granted - Kind: B2 - Application number: 15/655,383 - Filed: 2017-07-20 - Published: 2019-01-24 - Granted: 2019-11-19 - Earliest claimed: 2017-07-20 - Assignees: Allegro MicroSystems, LLC - Applicants: Allegro MicroSystems, LLC - Inventors: Thomas Kerdraon; Gary T. Pepka; Dominikus Maisl; Manfred Busch - Web page: https://patentgrep.com/patent/US10480957B2 ## CPC - G01D 5/145: {influenced by the relative movement between the Hall device and magnetic fields (see G01R33/06)} - G01D 5/165: by relative movement of a point of contact {or actuation} and a resistive track - G01P 3/487: delivered by rotating magnets - G01R 33/072: {Constructional adaptation of the sensor to specific applications} - G01R 33/091: {Constructional adaptation of the sensor to specific applications} - G01D: MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR - G01P: MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT (measuring or recording blood flow A61B5/02, A61B8/06; monitoring speed or deceleration of electrically-propelled vehicles B60L3/00; vehicle lighting systems adapted to indicate speed B60Q1/54; determining position or course in navigation, measuring ground distance in geodesy or surveying G01C; combined measuring devices for measuring two or more variables of movement G01C23/00; measuring velocity of sound G01H; measuring velocity of light G01J7/00; measuring direction or velocity of solid objects by reception or emission of radiowaves or other waves and based on propagation effects, e.g. Doppler effect, propagation time, direction of propagation, G01S; measuring speed of nuclear radiation G01T; measuring acceleration of gravity G01V; {measuring or recording the speed of trains B61L23/00; speed indicators incorporated in motor vehicles B60K35/00; measuring frequency or phase G01R; traffic control G08G}) - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) ## Abstract In one aspect, an integrated circuit (IC) includes a magnetic field sensor to detect speed and direction of angular rotation of a rotating magnetic structure. The magnetic field sensor includes at least two magnetic field sensing elements configured to sense changes in a magnetic field caused by rotation of the magnetic structure. The IC also includes an output port configured to provide an output signal of the magnetic field sensor. The output signal indicates the angular direction and one of the speed or a fault. ## Claims ### Claim 1 An integrated circuit (IC) comprising: a magnetic field sensor to detect speed and direction of angular rotation of a rotating magnetic structure, the magnetic field sensor comprising: at least two magnetic field sensing elements configured to sense changes in a magnetic field caused by rotation of the magnetic structure; and an output port configured to provide an output signal of the magnetic field sensor, the output signal indicating the angular direction and one of the speed or a fault, wherein the output signal at a first value or at a second value indicating the magnetic structure rotating in a first direction, wherein the output signal at a third value or at a fourth value indicating the magnetic structure rotating in a second direction opposite the first direction, wherein no two values of the first value, the second value, the third value or the fourth value are equal. ### Claim 2 (depends on 1) The IC of claim 1, wherein a frequency of the output signal indicates the speed or a fault. ### Claim 3 (depends on 2) The IC of claim 2, wherein the frequency within a frequency range indicates the speed. ### Claim 4 (depends on 3) The IC of claim 3, wherein the frequency below the frequency range indicates one or more faults. ### Claim 5 (depends on 3) The IC of claim 3, wherein the frequency above the frequency range indicates one or more faults. ### Claim 6 (depends on 3) The IC of claim 3, wherein the frequency above and below the frequency range indicates one or more faults. ### Claim 7 (depends on 1) The IC of claim 1, wherein the magnetic structure is a ring magnet. ### Claim 8 (depends on 1) The IC of claim 1, wherein at least one of the magnetic sensing elements is a Hall-effect element. ### Claim 9 (depends on 1) The IC of claim 1, wherein an amplitude of the output signal indicates the angular direction. ### Claim 10 (depends on 1) The IC of claim 1, wherein the output signal is a current signal. ### Claim 11 (depends on 1) The IC of claim 1, wherein the fault indicating at least one of: a loose wire, malfunction of the IC, a gap between the magnetic structure and the IC being above or below a distance threshold or a temperature of the IC exceeds a temperature threshold. ### Claim 12 (depends on 1) The IC of claim 1, wherein at least one of the at least two magnetic field sensing elements comprises at least one of a Hall effect element, a magnetoresistance element, or a magnetotransistor. ### Claim 13 (depends on 12) The IC of claim 12, wherein the magnetoresistance element comprises at least one of a giant magnetoresistance (GMR) element, an anisotropic magnetoresistance element (AMR), a tunneling magnetoresistance (TMR) element, and a magnetic tunnel junction (MTJ). ### Claim 14 An integrated circuit (IC) comprising: a magnetic field sensor to detect speed and direction of angular rotation of a rotating magnetic structure, the magnetic field sensor comprising: at least two magnetic field sensing elements configured to sense changes in a magnetic field caused by rotation of the magnetic structure; and an output port configured to provide an output signal of the magnetic field sensor, the output signal indicating the angular direction and one of the speed or a fault, wherein the output signal at a first value or at a second value indicating the magnetic structure rotating in a first direction, wherein the output signal at a third value or at a fourth value indicating the magnetic structure rotating in a second direction opposite the first direction, wherein the first value and the third value are equal. ### Claim 15 (depends on 14) The IC of claim 14, wherein a frequency of the output signal indicates the speed or a fault, wherein the frequency within a frequency range indicates the speed, wherein the frequency below the frequency range indicates one or more faults, and wherein the frequency above the frequency range indicates one or more faults. ### Claim 16 (depends on 14) The IC of claim 14, wherein the magnetic structure is a ring magnet. ### Claim 17 (depends on 14) The IC of claim 14, wherein at least one of the magnetic sensing elements is a Hall-effect element. ### Claim 18 (depends on 14) The IC of claim 14, wherein an amplitude of the output signal indicates the angular direction. ### Claim 19 (depends on 14) The IC of claim 14, wherein the output signal is a current signal. ### Claim 20 (depends on 14) The IC of claim 14, wherein the fault indicating at least one of: a loose wire, malfunction of the IC, a gap between the magnetic structure and the IC being above or below a distance threshold or a temperature of the IC exceeds a temperature threshold. ### Claim 21 (depends on 14) The IC of claim 14, wherein at least one of the at least two magnetic field sensing elements comprises at least one of a Hall effect element, a magnetoresistance element, or a magnetotransistor. ### Claim 22 (depends on 21) The IC of claim 21, wherein the magnetoresistance element comprises at least one of a giant magnetoresistance (GMR) element, an anisotropic magnetoresistance element (AMR), a tunneling magnetoresistance (TMR) element, or a magnetic tunnel junction (MTJ). ### Claim 23 An integrated circuit (IC) comprising: a magnetic field sensor to detect speed and direction of angular rotation of a rotating magnetic structure, the magnetic field sensor comprising: at least two magnetic field sensing elements configured to sense changes in a magnetic field caused by rotation of the magnetic structure; and an output port configured to provide an output signal of the magnetic field sensor, the output signal indicating the angular direction and one of the speed or a fault, wherein the magnetic field sensor further comprises: a first converter configured to convert a first signal from a first magnetic field sensing element to a first digital signal; a second converter configured to convert a second signal from a second magnetic field sensing element to a second digital signal; direction detection circuitry configured to receive the first digital signal and the second digital signal and to provide a direction signal; a frequency locked loop configured to receive the first digital signal and to provide a frequency signal; a decoder to receive the direction signal and the frequency signal; and a two-wire circuit configured to receive at least three signals from the decoder and to provide the output signal. ### Claim 24 (depends on 23) The IC of claim 23, wherein the two-wire circuit is configured to receive four signals from the decoder. ### Claim 25 (depends on 23) The IC of claim 23, wherein the two-wire circuit comprises: a voltage divider; and an operational amplifier coupled to the voltage divider, wherein the at least three signals are configured to enable gates in the voltage divider. ### Claim 26 An integrated circuit (IC) comprising: a magnetic field sensor means to detect speed and direction of angular rotation of a rotating magnetic structure, the magnetic field sensor means comprising: a means to sense changes in a magnetic field caused by rotation of the magnetic structure; and an output port configured to provide an output signal of the magnetic field sensor means, the output signal indicating the angular direction and one of the speed or a fault, wherein the output signal at a first value or at a second value indicating the magnetic structure rotating in a first direction, wherein the output signal at a third value or at a fourth value indicating the magnetic structure rotating in a second direction opposite the first direction, wherein the first value and the third value are equal. ### Claim 27 (depends on 26) The IC of claim 26, wherein a frequency of the output signal indicates the speed or a fault, wherein the frequency within a frequency range indicates the speed, wherein the frequency below the frequency range indicates one or more faults, and wherein the frequency above the frequency range indicates one or more faults. ### Claim 28 (depends on 26) The IC of claim 26, wherein the magnetic structure is a ring magnet. ### Claim 29 (depends on 26) The IC of claim 26, wherein at least one of the magnetic sensing elements is a Hall-effect element. ### Claim 30 (depends on 26) The IC of claim 26, wherein an amplitude of the output signal indicates the angular direction. ### Claim 31 (depends on 26) The IC of claim 26, wherein the output signal is a current signal. ### Claim 32 (depends on 26) The IC of claim 26, wherein the fault indicating at least one of: a loose wire, malfunction of the IC, a gap between the magnetic structure and the IC being above or below a distance threshold or a temperature of the IC exceeds a temperature threshold. ### Claim 33 (depends on 26) The IC of claim 26, wherein at least one of the at least two magnetic field sensing elements comprises at least one of a Hall effect element, a magnetoresistance element, or a magnetotransistor. ### Claim 34 (depends on 33) The IC of claim 33, wherein the magnetoresistance element comprises at least one of a giant magnetoresistance (GMR) element, an anisotropic magnetoresistance element (AMR), a tunneling magnetoresistance (TMR) element, or a magnetic tunnel junction (MTJ). ### Claim 35 An integrated circuit (IC) comprising: a magnetic field sensor to detect speed and direction of angular rotation of a rotating magnetic structure, the magnetic field sensor comprising: at least two magnetic field sensing elements configured to sense changes in a magnetic field caused by rotation of the magnetic structure; and an output port configured to provide an output signal of the magnetic field sensor, the output signal indicating the angular direction of the rotating magnetic structure and a fault indicator, wherein a frequency of the output signal is the fault indicator indicating no faults are detected or a fault is detected, wherein the frequency within a frequency range indicates no faults are detected and the speed of the rotating magnetic structure, wherein the frequency below the frequency range indicates one or more faults, and wherein the frequency above the frequency range indicates one or more faults. ### Claim 36 (depends on 35) The IC of claim 35, wherein the rotating magnetic structure is a ring magnet. ### Claim 37 (depends on 35) The IC of claim 35, wherein at least one of the magnetic sensing elements is a Hall-effect element. ### Claim 38 (depends on 35) The IC of claim 35, wherein an amplitude of the output signal indicates the angular direction. ### Claim 39 (depends on 35) The IC of claim 35, wherein the output signal is a current signal. ### Claim 40 (depends on 35) The IC of claim 35, wherein the fault indicating at least one of: a loose wire, malfunction of the IC, a gap between the magnetic structure and the IC being above or below a distance threshold or a temperature of the IC exceeds a temperature threshold. ### Claim 41 (depends on 35) The IC of claim 35, wherein at least one of the at least two magnetic field sensing elements comprises at least one of a Hall effect element, a magnetoresistance element, or a magnetotransistor. ### Claim 42 (depends on 41) The IC of claim 41, wherein the magnetoresistance element comprises at least one of a giant magnetoresistance (GMR) element, an anisotropic magnetoresistance element (AMR), a tunneling magnetoresistance (TMR) element, or a magnetic tunnel junction (MTJ). ### Claim 43 An integrated circuit (IC) comprising: a magnetic field sensor means to detect speed and direction of angular rotation of a rotating magnetic structure, the magnetic field sensor means comprising: a means to sense changes in a magnetic field caused by rotation of the magnetic structure; and an output port configured to provide an output signal of the magnetic field sensor means, the output signal indicating the angular direction and one of the speed or a fault, wherein the output signal at a first value or at a second value indicating the magnetic structure rotating in a first direction, wherein the output signal at a third value or at a fourth value indicating the magnetic structure rotating in a second direction opposite the first direction, wherein no two values of the first value, the second value, the third value or the fourth value are equal. ### Claim 44 (depends on 43) The IC of claim 43, wherein a frequency of the output signal indicates the speed or a fault. ### Claim 45 (depends on 44) The IC of claim 44, wherein the frequency within a frequency range indicates the speed. ### Claim 46 (depends on 45) The IC of claim 45, wherein the frequency below the frequency range indicates one or more faults. ### Claim 47 (depends on 45) The IC of claim 45, wherein the frequency above the frequency range indicates one or more faults. ### Claim 48 (depends on 45) The IC of claim 45, wherein the frequency above or below the frequency range indicates one or more faults. ### Claim 49 (depends on 45) The IC of claim 45, wherein the magnetic structure is a ring magnet. ### Claim 50 (depends on 43) The IC of claim 43, wherein an amplitude of the output signal indicates the angular direction. ### Claim 51 (depends on 43) The IC of claim 43, wherein the output signal is a current signal. ### Claim 52 (depends on 43) The IC of claim 43, wherein the fault indicating at least one of: a loose wire, malfunction of the IC, a gap between the magnetic structure and the IC being above or below a distance threshold or a temperature of the IC exceeds a temperature threshold.