# US 9,753,098 B2 · Magnetic sensor having enhanced linearization by applied field angle rotation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,753,098 B2 - Document ID: US9753098B2 - Status: Granted - Kind: B2 - Application number: 15/263,842 - Filed: 2016-09-13 - Published: 2017-02-09 - Granted: 2017-09-05 - Earliest claimed: 2015-08-07 - Assignees: Allegro MicroSystems, LLC - Applicants: Allegro Microsystems, LLC - Inventors: Alexander Latham - Web page: https://patentgrep.com/patent/US9753098B2 ## CPC - G01R 33/0082: {Compensation, e.g. compensating for temperature changes} - G01R 33/093: {using multilayer structures, e.g. giant magnetoresistance sensors (thin magnetic films H01F10/00)} - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) ## Abstract Method and apparatus for a current sensing device including a magnetoresistive magnetic field sensing element positioned with respect to a shaped conductor such that an applied field generated by current through the shaped conductor forms an offset angle theta defined by the applied field and a field of a pinning layer of the magnetoresistive element. The offset angle increases a linearity of the device output for current in the shaped conductor flowing in a first direction. A further sensor can increase linearity in the opposite direction. ## Claims ### Claim 1 A device, comprising: a first magnetoresistive magnetic field sensing element positioned with respect to a shaped conductor such that an applied field generated by current through the shaped conductor forms an offset angle theta defined by the applied field and a field of a pinning layer of the first magnetoresistive magnetic field sensing element, wherein the offset angle theta is greater than about five degrees to increase a linearity of an output of the first magnetoresistive magnetic field sensing element for current in the shaped conductor flowing in a first direction; and an output module to receive the linearized signal and provide a device output signal. ### Claim 2 (depends on 1) The device according to claim 1, wherein the first magnetoresistive magnetic field sensing element comprises a GMR element. ### Claim 3 (depends on 2) The device according to claim 2, wherein the GMR element comprises a second pinned layer providing a reference field substantially perpendicular to the field of the first pinned layer. ### Claim 4 (depends on 1) The device according to claim 1, wherein the first magnetoresistive magnetic field sensing element comprises a magnetoresistive element selected from a group consisting of a semiconductor magnetoresistive element, a giant magnetoresistive (GMR) element, an anisotropic magnetoresistive element (AMR), a tunneling magnetoresistive (TMR) element, and a magnetic tunnel junction (MTJ). ### Claim 5 (depends on 1) The device according to claim 1, wherein the first magnetoresistive magnetic field sensing element comprises magnetic sensors arranged in a Wheatstone bridge configuration. ### Claim 6 (depends on 5) The device according to claim 5, wherein first and second ones of the magnetic sensors are magnetically shielded for linear field sensing. ### Claim 7 (depends on 1) The device according to claim 1, wherein a supply voltage controls a gain of the magnetic field sensing element over temperature. ### Claim 8 (depends on 1) The device according to claim 1, wherein the shaped conductor comprises an arcuate portion coupled at each end to respective linear portions. ### Claim 9 (depends on 8) The device according to claim 8, wherein the first magnetoresistive magnetic field sensing element comprises elements in a bridge configuration such that the elements in the bridge configuration are positioned on the arcuate portion of the shaped conductor. ### Claim 10 (depends on 9) The device according to claim 9, wherein a direction of current flow in the shaped conductor is determined in the bridge configuration. ### Claim 11 (depends on 1) The device according to claim 1, further including a second magnetoresistive magnetic field sensing element to increase linearity of the output for current flow in the shaped conductor in the opposite direction. ### Claim 12 (depends on 11) The device according to claim 11, wherein an applied angle for the second magnetoresistive magnetic field sensing element is about equal to 180 minus theta, where theta is the applied angle for the first magnetoresistive magnetic field sensing element. ### Claim 13 (depends on 11) The device according to claim 11, wherein the first magnetoresistive magnetic field sensing element has a die orientation 180 degrees to the second magnetoresistive magnetic field sensing element. ### Claim 14 A device, comprising: a magnetic field sensor means for sensing current in a shaped conductor at an offset angle theta defined by the applied field and a field of a pinning layer of the first magnetic field sensor means, wherein the offset angle theta is greater than about five degrees to increase a linearity of an output of the first magnetic field sensor means for current in the shaped conductor flowing in a first direction; and an output module to receive the linearized signal and provide a device output signal. ### Claim 15 (depends on 14) The device according to claim 14, further including a second magnetic field sensor means for increasing linearity of the output for current flow in the shaped conductor in the opposite direction. ### Claim 16 (depends on 14) The device according to claim 14, wherein the first magnetic field sensor means comprises a GMR element. ### Claim 17 (depends on 16) The device according to claim 16, wherein the GMR element comprises a second pinned layer providing a reference field substantially perpendicular to the field of the first pinned layer. ### Claim 18 (depends on 14) The device according to claim 14, wherein the first magnetic field sensor means comprises a magnetoresistive element selected from a group consisting of a semiconductor magnetoresistive element, a giant magnetoresistive (GMR) element, an anisotropic magnetoresistive element (AMR), a tunneling magnetoresistive (TMR) element, and a magnetic tunnel junction (MTJ). ### Claim 19 (depends on 14) The device according to claim 14, wherein the first magnetic field sensor means comprises magnetic sensors arranged in a Wheatstone bridge configuration. ### Claim 20 (depends on 19) The device according to claim 19, wherein a direction of current flow in the shaped conductor is determined in the bridge configuration. ### Claim 21 A method, comprising: positioning a first magnetoresistive magnetic field sensing element with respect to a shaped conductor such that an applied field generated by current through the shaped conductor forms an offset angle theta defined by the applied field and a field of a pinning layer of the first magnetoresistive magnetic field sensing element, wherein the offset angle theta is greater than about five degrees to increase a linearity of an output of the first magnetoresistive magnetic field sensing element for current in the shaped conductor flowing in a first direction; and employing an output module to receive the linearized signal and provide a device output signal. ### Claim 22 (depends on 21) The method according to claim 21, further including positioning a second magnetoresistive magnetic field sensing element to increase linearity of the output for current flow in the shaped conductor in the opposite direction. ### Claim 23 (depends on 21) The method according to claim 21, wherein the first magnetoresistive magnetic field sensing element comprises a GMR element. ### Claim 24 (depends on 21) The method according to claim 21, wherein the first magnetoresistive magnetic field sensing element comprises a magnetoresistive element selected from a group consisting of a semiconductor magnetoresistive element, a giant magnetoresistive (GMR) element, an anisotropic magnetoresistive element (AMR), a tunneling magnetoresistive (TMR) element, and a magnetic tunnel junction (MTJ). ### Claim 25 (depends on 21) The method according to claim 21, wherein the first magnetoresistive magnetic field sensing element comprises magnetic sensors arranged in a Wheatstone bridge configuration. ### Claim 26 (depends on 21) The method according to claim 21, further including determining a direction of current flow in the shaped conductor in a bridge configuration. ### Claim 27 A device, comprising: a first magnetoresistive magnetic field sensing element positioned with respect to a shaped conductor such that an applied field generated by current through the shaped conductor forms an offset angle theta defined by the applied field and a field of a first pinned layer of the first magnetoresistive magnetic field sensing element, wherein the offset angle theta is greater than about five degrees to increase a linearity of an output of the first magnetoresistive magnetic field sensing element for current in the shaped conductor flowing in a first direction, wherein the output of the first magnetoresistive magnetic field sensing element increases in linearity as the applied field changes in a first direction and decreases in linearity as the applied field changes in a second direction that is opposite to the first direction; and an output module to receive the output of the first magnetoresistive magnetic field sensing element and provide a device output signal, wherein the shaped conductor comprises an arcuate portion coupled at each end to respective linear portions, and wherein the first magnetoresistive magnetic field sensing element comprises elements in a bridge configuration such that at least some of the elements in the bridge configuration are positioned on the arcuate portion of the shaped conductor. ### Claim 28 (depends on 27) The device according to claim 27, wherein first magnetoresistive magnetic field sensing element comprises a TMR element. ### Claim 29 (depends on 27) The device according to claim 27, wherein the first magnetoresistive magnetic field sensing element comprises a second pinned layer providing a reference field substantially perpendicular to the field of the first pinned layer. ### Claim 30 (depends on 27) The device according to claim 27, wherein the first magnetoresistive magnetic field sensing element comprises magnetic sensors arranged in a Wheatstone bridge configuration. ### Claim 31 (depends on 27) The device according to claim 27, wherein a direction of current flow in the shaped conductor is determined in the bridge configuration. ### Claim 32 (depends on 27) The device according to claim 27, further including a second magnetoresistive magnetic field sensing element to increase linearity of the output for current flow in the shaped conductor in the opposite direction. ### Claim 33 (depends on 32) The device according to claim 32, wherein an applied angle for the second magnetoresistive magnetic field sensing element is about equal to 180 minus theta, where theta is the applied angle for the first magnetoresistive magnetic field sensing element. ### Claim 34 (depends on 32) The device according to claim 32, wherein the first magnetoresistive magnetic field sensing element has a die orientation 180 degrees to the second magnetoresistive magnetic field sensing element.