# US 2018/0321330 A1 · Magnetic field compensation device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0321330 A1 - Document ID: US20180321330A1 - Status: Published application - Kind: A1 - Application number: 15/646,641 - Filed: 2017-07-11 - Published: 2018-11-08 - Earliest claimed: 2017-05-08 - Assignees: TDK-Micronas GmbH - Applicants: TDK-Micronas GmbH - Inventors: Joerg FRANKE - Web page: https://patentgrep.com/patent/US20180321330A1 ## CPC - G01R 33/025: Compensating stray fields {(G01R33/0017 takes precedence)} - G01R 33/0017: {Means for compensating offset magnetic fields or the magnetic flux to be measured; Means for generating calibration magnetic fields} - G01R 33/07: Hall effect devices - H10N 52/101: {Semiconductor Hall-effect devices} - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) - H10N: ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR ## Abstract Magnetic field compensation device having a first bar-shaped flux concentrator and a second bar-shaped flux concentrator, wherein the first flux concentrator and the second flux concentrator are separated from one another in a y-direction, and the longitudinal axis of the first flux concentrator and the longitudinal axis of the second flux concentrator are arranged to be substantially parallel to one another. A control unit is in an operative electrical connection with the magnetic field sensor and the compensating coil, and the control unit is equipped to control the compensating current through the compensating coil using a measured signal from the magnetic field sensor in such a manner that, for an external magnetic field formed in the x-direction at the location of the magnetic field sensor, the magnetic field is substantially compensated. ## Claims ### Claim 1 Magnetic field compensation device comprising: a first bar-shaped flux concentrator with a longitudinal axis formed in an x-direction and with a first head end, a second bar-shaped flux concentrator with a longitudinal axis formed in the x-direction, wherein the first flux concentrator and the second flux concentrator are separated from one another in a y-direction, and the longitudinal axis of the first flux concentrator and the longitudinal axis of the second flux concentrator are arranged to be substantially parallel to one another, a magnetic field sensor, a compensating coil formed around the first flux concentrator and/or around the second flux concentrator, a control unit, wherein the control unit is in an operative electrical connection with the magnetic field sensor and the compensating coil, and the control unit is equipped to control a compensating current through the compensating coil using a measured signal from the magnetic field sensor in such a manner that, for an external magnetic field formed in the x-direction at the location of the magnetic field sensor, the magnetic field is substantially compensated, wherein, in the second flux concentrator, the magnetic field is formed in the direction of the x-axis, and the magnetic field sensor is located at the head end of the first flux concentrator, and the magnetic field sensor and the first flux concentrator and the second flux concentrator and the compensating coil and the control unit are each predominantly integrated into a semiconductor substrate. ### Claim 2 (depends on 1) Magnetic field compensation device according to claim 1, wherein the length of the second flux concentrator is greater than the length of the first flux concentrator in the x-direction, or the length of the second flux concentrator is less than the length of the first flux concentrator in the x-direction, or in that the lengths of the two flux concentrators are equal. ### Claim 3 (depends on 1) Magnetic field compensation device according to claim 1, wherein the first flux concentrator and/or the second flux concentrator passes completely through the compensating coil. ### Claim 4 (depends on 1) Magnetic field compensation device according to claim 1, wherein a third bar-shaped flux concentrator with a longitudinal axis formed in the y-direction is provided between the first flux concentrator and the second flux concentrator. ### Claim 5 (depends on 4) Magnetic field compensation device according to claim 4, wherein the third flux concentrator is magnetically coupled to the first flux concentrator and/or to the second flux concentrator. ### Claim 6 (depends on 1) Magnetic field compensation device according to claim 1, wherein the compensating coil is formed around the third flux concentrator and/or around the first flux concentrator, or the compensating coil is formed around all the flux concentrators. ### Claim 7 (depends on 1) Magnetic field compensation device according to claim 1, wherein the compensating coil is formed fully or at least partially around the magnetic field sensor. ### Claim 8 (depends on 1) Magnetic field compensation device according to claim 1, wherein a fourth bar-shaped flux concentrator with a longitudinal axis formed in the x-direction is provided, and the fourth flux concentrator is spaced apart from the first flux concentrator opposite to the y-direction, and the longitudinal axis of the first flux concentrator and the longitudinal axis of the fourth flux concentrator are made to be substantially parallel to one another. ### Claim 9 (depends on 7) Magnetic field compensation device according to claim 7, wherein a fifth bar-shaped flux concentrator (400) with a longitudinal axis formed in the y-direction is provided. ### Claim 10 (depends on 8) Magnetic field compensation device according to claim 8, wherein the fifth flux concentrator is magnetically coupled to the first flux concentrator (20) and/or to the fourth flux concentrator. ### Claim 11 (depends on 1) Magnetic field compensation device according to claim 1, wherein the arrangement of the flux concentrators and the arrangement of the compensating coil are implemented with mirror-image symmetry about a y-z surface, so that the arrangement is composed of two sections. ### Claim 12 (depends on 10) Magnetic field compensation device according to claim 10, wherein the two sections are magnetically coupled to one another. ### Claim 13 (depends on 1) Magnetic field compensation device according to claim 1, characterized in that the flux concentrators are each implemented as a single piece. ### Claim 14 (depends on 1) Magnetic field compensation device according to claim 1, wherein the magnetic field sensor and the first flux concentrator and the second flux concentrator and the compensating coil and the control unit are all integrated into the same semiconductor substrate. ### Claim 15 (depends on 1) Magnetic field compensation device according to claim 1, wherein the flux concentrators are connected to one another in a magnetically conductive manner or a gap is formed between the flux concentrators, wherein the gap between the flux concentrators is smaller than 4 times the diameter or smaller than the diameter of the first flux concentrator. ### Claim 16 (depends on 1) Magnetic field compensation device according to claim 1, wherein the direction of the magnetic field created in the first flux concentrator by the compensating coil is opposite to the direction of the magnetic field induced in the second flux concentrator by the compensating coil. ### Claim 17 (depends on 1) Magnetic field compensation device according to claim 1, wherein the cross-section of the windings changes along the length of the compensating coil. ### Claim 18 (depends on 1) Magnetic field compensation device according to claim 1, wherein the compensating coil is formed around only the first flux concentrator and/or around the magnetic field sensor. ### Claim 19 (depends on 1) Magnetic field compensation device according to claim 1, wherein the magnetic field sensor is implemented as a Hall sensor or as a GMR sensor or as a TMR sensor, or in that two different types of magnetic field sensor are implemented. ### Claim 20 (depends on 1) Magnetic field compensation device according to claim 1, wherein the magnetic field sensor is implemented as a Hall sensor formed in the semiconductor substrate.