Multi-axis TMR sensor correction circuit and system

Abstract

The invention discloses a multi-axis TMR sensor correction circuit and system, the correction circuit comprises a sensor unit, a voltage signal input end, a correction unit and a voltage signal output end, the voltage signal input end is respectively connected with the sensor unit and the correction unit, and the voltage signal output end is connected with the correction unit; the sensor unit outputs voltage signals based on TMR magnetic sensing characteristics, uncorrected voltage signals are input to the correction unit, the correction unit corrects the uncorrected voltage signals to obtain corrected voltage signals, and the corrected voltage signals are output through the voltage signal output end. It can be seen that the sensor unit outputs the original voltage signal based on the TMR magnetic sensing characteristics, namely the uncorrected voltage signal, the correction unit corrects and calculates the uncorrected voltage signal, the corrected signal serves as the accurate magnetic sensing signal, the magnetic sensing signal is not prone to being interfered by an external magnetic field, and therefore the accuracy of the output signal is improved.

Description

Technical Field

[0001] This application relates to the field of TMR sensor technology, and in particular to a multi-axis TMR sensor calibration circuit and system. Background Technology

[0002] A TMR (Tunnel Magneto Resistance) sensor is a sensor based on the magnetoresistive effect, used to measure physical quantities such as magnetic fields, displacement, and velocity. TMR sensors offer advantages such as high sensitivity, fast response, low power consumption, and high integration, and are widely used in commercial and industrial applications.

[0003] The electrical signals output by common single-axis or multi-axis TMR sensors are easily interfered with by external magnetic fields, resulting in significant errors in the output signals. Summary of the Invention

[0004] In view of this, this application provides a multi-axis TMR sensor calibration circuit and system for calibrating the output signal of a multi-axis TMR sensor to make it antimagnetic.

[0005] In a first aspect, this application provides a multi-axis TMR sensor calibration circuit, the calibration circuit including a sensor unit, a voltage signal input terminal, a calibration unit and a voltage signal output terminal, the voltage signal input terminal being connected to the sensor unit and the calibration unit respectively, and the voltage signal output terminal being connected to the calibration unit;

[0006] The sensor unit is used to output a voltage signal based on the TMR magnetic sensing characteristics;

[0007] The voltage signal input terminal is used to receive the voltage signal output by the sensor unit;

[0008] The correction unit is used to correct the voltage signal to obtain a corrected voltage signal;

[0009] The voltage signal output terminal is used to output the corrected voltage signal.

[0010] Optionally, the sensor unit includes an X-axis sensing unit and a Y-axis sensing unit; wherein the X-axis sensing unit is used to sense the magnetic field in the X-axis direction, and the Y-axis sensing unit is used to sense the magnetic field in the Y-axis direction.

[0011] The X-axis sensing unit consists of an x-TMR sensing element and a voltage subtractor.

[0012] The Y-axis sensing unit consists of a y-TMR sensing element and a voltage subtractor.

[0013] The first voltage signal output by the X-axis sensing unit is related to the zero-field resistance and linearity coefficient of the x-TMR sensing element;

[0014] The second voltage signal output by the Y-axis sensing unit is related to the zero-field resistance and linearity coefficient of the y-TMR sensing element.

[0015] Optionally, the sensor unit further includes a Z-axis sensing unit for sensing the magnetic field in the Z-axis direction; the Z-axis sensing unit consists of a z-TMR sensing element and a voltage subtractor.

[0016] The third voltage signal output by the Z-axis sensing unit is related to the zero-field resistance and linearity coefficient of the z-TMR sensing element.

[0017] Optionally, the correction unit includes a first correction submodule and a second correction submodule;

[0018] The first correction submodule is used to receive the first voltage signal, the second voltage signal and the first preset voltage parameter, and correct the first voltage signal according to the first voltage correction algorithm to obtain the corrected first voltage signal;

[0019] The second correction submodule is used to receive the first voltage signal, the second voltage signal and the second preset voltage parameter, and correct the second voltage signal according to the first voltage correction algorithm to obtain the corrected second voltage signal.

[0020] Optionally, the correction unit further includes a third correction submodule;

[0021] The third correction submodule is used to receive the corrected first voltage signal, the corrected second voltage signal, and the third voltage signal, and correct the corrected first voltage signal, the corrected second voltage signal, and the third voltage signal according to the second voltage correction algorithm to obtain the corrected third voltage signal.

[0022] Optionally, the correction unit includes a fourth correction submodule and a fifth correction submodule;

[0023] The fourth correction submodule is used to receive the first voltage signal and the second voltage signal, and correct the first voltage signal according to the third voltage correction algorithm to obtain the corrected fourth voltage signal;

[0024] The fifth correction submodule is used to receive the first voltage signal and the second voltage signal, and correct the second voltage signal according to the third voltage correction algorithm to obtain the corrected fifth voltage signal.

[0025] Optionally, the correction unit further includes a sixth correction submodule;

[0026] The sixth correction submodule is used to receive the corrected fourth voltage signal, the corrected fifth voltage signal, and the third voltage signal, and correct the corrected fourth voltage signal, the corrected fifth voltage signal, and the third voltage signal according to the second voltage correction algorithm to obtain the corrected sixth voltage signal.

[0027] Optionally, the correction circuit has at least two or more of the voltage signal input terminals.

[0028] Optionally, the correction unit includes a voltage calculation unit, which is one or more of a voltage adder, a voltage subtractor, a voltage multiplier, and a voltage divider.

[0029] Secondly, this application provides a multi-axis TMR sensor calibration system, the system including a multi-axis TMR sensing module, a signal calibration module and a signal transmission module, wherein the signal transmission module is connected to the multi-axis TMR sensing module and the signal calibration module respectively;

[0030] The multi-axis TMR sensing module is used to output a voltage signal based on the magnetic sensing characteristics of TMR.

[0031] The signal correction module is used to correct the voltage signal and output the corrected voltage signal;

[0032] The signal transmission module is used to transmit signals between the multi-axis TMR sensing module and the signal correction module.

[0033] The above technical solution has the following beneficial effects:

[0034] This application provides a multi-axis TMR sensor calibration circuit and system. The calibration circuit includes a sensor unit, a voltage signal input terminal, a calibration unit, and a voltage signal output terminal. The voltage signal input terminal is connected to both the sensor unit and the calibration unit, and the voltage signal output terminal is connected to the calibration unit. The sensor unit outputs a voltage signal based on the TMR magnetic sensing characteristics. The voltage signal input terminal receives the voltage signal output by the sensor unit and inputs an uncalibrated voltage signal to the calibration unit. The calibration unit calibrates the uncalibrated voltage signal to obtain a calibrated voltage signal, which is then output through the voltage signal output terminal. Therefore, the sensor unit outputs the original voltage signal based on the TMR magnetic sensing characteristics, i.e., the uncalibrated voltage signal. The calibration unit performs correction calculations on this uncalibrated voltage signal and uses the corrected signal as the accurate magnetic sensing signal output, which is less susceptible to interference from external magnetic fields, thereby improving the accuracy of the output signal. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in this embodiment or the prior art, the drawings used in the description of the embodiment or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 A schematic diagram of a multi-axis TMR sensor calibration circuit provided in an embodiment of this application;

[0037] Figure 2 A circuit structure for an X-axis sensing unit provided in an embodiment of this application;

[0038] Figure 3 A circuit structure for the Y-axis sensing unit provided in the embodiments of this application;

[0039] Figure 4 A circuit structure for the Z-axis sensing unit provided in the embodiments of this application;

[0040] Figure 5 A schematic diagram of a circuit structure for a correction unit provided in an embodiment of this application;

[0041] Figure 6 A simulation diagram of a correction unit after first-order correction provided in an embodiment of this application;

[0042] Figure 7 This is another simulation diagram showing the correction unit after modification provided in the embodiments of this application;

[0043] Figure 8 A simulation diagram showing the correction unit provided in the embodiment of this application after complete correction;

[0044] Figure 9 This is a schematic diagram of a multi-axis TMR sensor calibration system provided in an embodiment of this application. Detailed Implementation

[0045] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0046] To facilitate a further understanding of the technical solutions provided in this application, the background technology involved in this application will be explained below.

[0047] TMR magnetic sensors possess advantages such as high sensitivity, fast response, low power consumption, and high integration, and are widely used in commercial and industrial scenarios. Their working principle can be briefly described as follows: when the MTJ (Magnetic Tunnel Junction) magnetic moment is subjected to a magnetic field, its direction shifts, causing a corresponding change in its TMR resistance. Generally, a TMR sensor has only one sensing axis. For example, for an in-plane TMR sensor, its magnetization direction under zero field is the x-axis, and the sensing magnetic field extends along the y-axis. The z-axis, due to its anisotropic shape, is immune to magnetic fields on the order of 1 Tesla. When the magnetic fields along the y-axis and z-axis are large, the following problems occur: 1. When Hx is on the order of Hy, the output TMR resistance has an error of 30% to 100%; 2. When Hz ≥ 1T, the output TMR resistance has an error ≥ 10%. For common single-axis or multi-axis TMR sensor chips, such as patent documents CN115840178A and CN112305473B or patent WO 2018 / 202085A, the output electrical signal of the sensor is not corrected and is easily interfered with by external magnetic fields, resulting in significant errors in the output signal.

[0048] To overcome the aforementioned technical problems, this application provides a multi-axis TMR sensor calibration circuit and system. The calibration circuit includes a sensor unit, a voltage signal input terminal, a calibration unit, and a voltage signal output terminal. The voltage signal input terminal is connected to both the sensor unit and the calibration unit, and the voltage signal output terminal is connected to the calibration unit. The sensor unit outputs a voltage signal based on the TMR magnetic sensing characteristics. The voltage signal input terminal receives the voltage signal output by the sensor unit and inputs an uncalibrated voltage signal to the calibration unit. The calibration unit calibrates the uncalibrated voltage signal to obtain a calibrated voltage signal, which is then output through the voltage signal output terminal. Therefore, the sensor unit outputs the original voltage signal based on the TMR magnetic sensing characteristics, i.e., the uncalibrated voltage signal. The calibration unit performs correction calculations on this uncalibrated voltage signal and uses the corrected signal as the accurate magnetic sensing signal output, which is less susceptible to interference from external magnetic fields, thereby improving the accuracy of the output signal.

[0049] See Figure 1 This is a schematic diagram of a multi-axis TMR sensor calibration circuit provided in an embodiment of this application. The calibration circuit includes a sensor unit, a voltage signal input terminal, a calibration unit, and a voltage signal output terminal. The voltage signal input terminal is connected to the sensor unit and the calibration unit, respectively, and the voltage signal output terminal is connected to the calibration unit.

[0050] The sensor unit is used to output a voltage signal based on the TMR magnetic sensing characteristics;

[0051] The voltage signal input terminal is used to receive the voltage signal output by the sensor unit;

[0052] The correction unit is used to correct the voltage signal to obtain a corrected voltage signal;

[0053] The voltage signal output terminal is used to output the corrected voltage signal.

[0054] In this embodiment, the correction circuit has at least two or more voltage signal input terminals and one voltage signal output terminal.

[0055] At least two of the voltage signal input ports are connected to the sensor unit to receive the voltage signal output by the sensor unit.

[0056] Up to five of the voltage signal input terminals are connected to the parameter control terminals to receive external voltage signals to control the operational amplifier parameters of the correction circuit.

[0057] The voltage signal output terminal outputs the corrected voltage signal.

[0058] It should be noted that in this embodiment, N uncorrected sensing voltage signals are input, and after passing through the correction circuit unit, one corrected sensing voltage signal is output. The N uncorrected sensing voltage signals come from N sensing units whose sensing axes are not parallel to each other (preferably orthogonal to each other). The sensing direction of the output voltage signal is parallel to the sensing axis of one of the N sensing units.

[0059] In one possible implementation, the correction unit includes a voltage calculation unit, which is one or more of a voltage adder, a voltage subtractor, a voltage multiplier, and a voltage divider.

[0060] In one possible implementation, the sensor unit includes an X-axis sensing unit and a Y-axis sensing unit; wherein the X-axis sensing unit is used to sense the magnetic field in the X-axis direction, and the Y-axis sensing unit is used to sense the magnetic field in the Y-axis direction.

[0061] The X-axis sensing unit consists of an x-TMR sensing element and a voltage subtractor.

[0062] The Y-axis sensing unit consists of a y-TMR sensing element and a voltage subtractor.

[0063] The first voltage signal output by the X-axis sensing unit is related to the zero-field resistance and linearity coefficient of the x-TMR sensing element;

[0064] The second voltage signal output by the Y-axis sensing unit is related to the zero-field resistance and linearity coefficient of the y-TMR sensing element.

[0065] In this embodiment, participants Figure 2 This is a circuit structure for the X-axis sensing unit provided in the embodiments of this application, participating in... Figure 3 This is a circuit structure of the Y-axis sensing unit provided in the embodiments of this application.

[0066] like Figure 2 As shown, the X-axis sensing unit is used to sense the magnetic field H in the X-axis direction. x It consists of an x-TMR sensing element and a voltage subtractor.

[0067] The first voltage signal output by the X-axis sensing unit is:

[0068]

[0069] Where Vcc is the supply voltage, R x0 and k x Hx represents the zero-field resistance and linearity coefficient of the x-TMR sensing element, respectively, and Hx represents the magnetic field in the X-axis direction.

[0070] The first voltage signal output by the X-axis sensing unit is related to the zero-field resistance and linearity coefficient of the x-TMR sensing element.

[0071] like Figure 3 As shown, the Y-axis sensing unit is used to sense the magnetic field H in the Y-axis direction. y It consists of a y-TMR sensing element and a voltage subtractor.

[0072] The second voltage signal output by the Y-axis sensing unit is:

[0073]

[0074] Among them, R y0 and k y Here, represents the zero-field resistance and linearity coefficient of the y-TMR sensing element, respectively, and Hy represents the magnetic field along the Y-axis.

[0075] The second voltage signal output by the Y-axis sensing unit is related to the zero-field resistance and linearity coefficient of the y-TMR sensing element.

[0076] In one possible implementation, such as Figure 4 The diagram shows a circuit structure of a Z-axis sensing unit provided in an embodiment of this application.

[0077] like Figure 4 As shown, the Z-axis sensing unit is used to sense the magnetic field H in the Z-axis direction. z It consists of a z-TMR sensing element and a voltage subtractor.

[0078] The third voltage signal output by the Z-axis sensing unit is:

[0079]

[0080] Among them, R z0 and k z , respectively, represent the zero-field resistance and linearity coefficient of the z-TMR sensing element, and Hz represents the magnetic field in the Z-axis direction.

[0081] The third voltage signal output by the Z-axis sensing unit is related to the zero-field resistance and linearity coefficient of the z-TMR sensing element.

[0082] It should be noted that the correction algorithm implemented by the correction circuit is not unique and can be set according to the performance of the device. Please refer to the following example for details.

[0083] In one possible implementation, the correction unit includes a first correction submodule and a second correction submodule;

[0084] The first correction submodule is used to receive the first voltage signal, the second voltage signal and the first preset voltage parameter, and correct the first voltage signal according to the first voltage correction algorithm to obtain the corrected first voltage signal;

[0085] The second correction submodule is used to receive the first voltage signal, the second voltage signal and the second preset voltage parameter, and correct the second voltage signal according to the first voltage correction algorithm to obtain the corrected second voltage signal.

[0086] Specifically, such as Figure 5 The diagram shown is a schematic diagram of a circuit structure of a correction unit provided in an embodiment of this application.

[0087] The first correction submodule is used to receive the first voltage signal, the second voltage signal and the first preset voltage parameter, and correct the first voltage signal according to the first voltage correction algorithm to obtain the corrected first voltage signal.

[0088] Specifically, the first voltage signal is corrected according to the first voltage correction algorithm to obtain the corrected first voltage signal Vx. out for:

[0089]

[0090] In this formula, Vx is the first voltage signal output by the X-axis sensing unit, and Vy is the second voltage signal output by the Y-axis sensing unit. It should be noted that the first preset voltage parameter Vy... Ref This is the voltage parameter that needs to be input into the analog circuit; this parameter is a fixed value.

[0091] The second correction submodule is used to receive the first voltage signal, the second voltage signal and the second preset voltage parameter, and correct the second voltage signal according to the first voltage correction algorithm to obtain the corrected second voltage signal.

[0092] Specifically, the second voltage signal is corrected according to the first voltage correction algorithm to obtain the corrected second voltage signal Vy. out for:

[0093]

[0094] It should be noted that the second preset voltage parameter Vx Ref The voltage parameter required in this analog circuit is a fixed value.

[0095] It should be noted that Vx and Vy satisfy the following calculation formulas respectively:

[0096]

[0097] Wherein, Vx and Vy are the differential voltages output by the x and y sensors, respectively (refer to Example 1), both determined by Vcc and characteristic coefficients kx' and ky'. kx' and ky' can be obtained by measuring the Vx-Hx and Vy-Hy curves, respectively. VxRef and VyRef are correction parameters, which can be tested by applying a two-dimensional magnetic field and adjusting to a suitable level according to the principle of minimizing error.

[0098] The Vcc setting should satisfy the following relationship: when Hx = Hsx and Hy = 0, Vx = Vcc; when Hy = Hsy and Hx = 0, Vy = Vcc; where Hsx and Hsy are the saturation magnetic fields of the sensor, respectively.

[0099] like Figure 6 The diagram shown is a simulation schematic of a correction unit after first-order correction provided in an embodiment of this application.

[0100] from Figure 6 It can be seen that the simulated curves of the first and second voltage signals do not match their expected simulated curves, and are easily interfered with by external magnetic fields, resulting in significant errors in the output signals. In contrast, the corrected first voltage signal Vx (1st order correction) and the corrected first voltage signal Vy (1st order correction) match their expected simulated curves relatively well and are not easily interfered with by external magnetic fields.

[0101] In one possible implementation, the correction unit further includes a third correction submodule;

[0102] The third correction submodule is used to receive the corrected first voltage signal, the corrected second voltage signal, and the third voltage signal, and correct the corrected first voltage signal, the corrected second voltage signal, and the third voltage signal according to the second voltage correction algorithm to obtain the corrected third voltage signal.

[0103] In this embodiment, the inputs of the third correction submodule are the corrected first voltage signal, the corrected second voltage signal, and the third voltage signal output by the Z-axis sensing unit. The corrected first voltage signal, the corrected second voltage signal, and the third voltage signal are corrected according to the second voltage correction algorithm to obtain the corrected third voltage signal.

[0104] Specifically, the corrected first voltage signal, the corrected second voltage signal, and the third voltage signal are corrected according to the second voltage correction algorithm to obtain the corrected third voltage signal Vz. out for:

[0105]

[0106] Where: Vx out and Vy out These are the corrected first voltage signal and the corrected second voltage signal, respectively, and Vz is the third voltage signal output by the Z-axis sensing unit.

[0107] The Vcc setting should satisfy the following relationship: when Hz = Hsz and Hy = Hx = 0, Vz = Vcc, where Hsz is the saturated magnetic field of the z-axis sensor; VIP is the in-plane magnetic field output voltage, which is obtained by summing the squares of Vxout and Vyout.

[0108] like Figure 7 The diagram shown is another simulation illustration of the correction unit provided in the embodiment of this application after correction.

[0109] from Figure 7 It can be seen that the simulated curve of the third voltage signal does not match its expected simulated curve, and it is easily interfered with by external magnetic fields, resulting in significant errors in the output signal. In contrast, the corrected third voltage signal Vz (after correction) matches its expected simulated curve relatively well and is less susceptible to interference from external magnetic fields.

[0110] In one possible implementation, the correction unit includes a fourth correction submodule and a fifth correction submodule;

[0111] The fourth correction submodule is used to receive the first voltage signal and the second voltage signal, and correct the first voltage signal according to the third voltage correction algorithm to obtain the corrected fourth voltage signal;

[0112] The fifth correction submodule is used to receive the first voltage signal and the second voltage signal, and correct the second voltage signal according to the third voltage correction algorithm to obtain the corrected fifth voltage signal.

[0113] Specifically, the fourth correction submodule is used to receive the first voltage signal and the second voltage signal, and correct the first voltage signal according to the third voltage correction algorithm to obtain the corrected fourth voltage signal.

[0114] The first voltage signal is corrected according to the third voltage correction algorithm to obtain the corrected first voltage signal as follows:

[0115]

[0116] In this formula, Vx' is the cosine signal of Vx, and Vy' is the cosine signal of Vy.

[0117] The fifth correction submodule is used to receive the first voltage signal and the second voltage signal, and correct the second voltage signal according to the third voltage correction algorithm to obtain the corrected fifth voltage signal.

[0118] Specifically, the second voltage signal is corrected according to the third voltage correction algorithm to obtain the corrected second voltage signal as follows:

[0119]

[0120] In this formula, Vx' is the cosine signal of Vx, and Vy' is the cosine signal of Vy.

[0121] Wherein, Vx' and Vy' satisfy the following calculation formulas respectively:

[0122]

[0123]

[0124] The Vcc setting should satisfy the following relationship: when Hx = Hsx and Hy = 0, Vx = Vcc; when Hy = Hsy and Hx = 0, Vy = Vcc; where Hsx and Hsy are the saturation magnetic fields of the sensor, respectively.

[0125] like Figure 8 The diagram shown is a simulation illustration of a correction unit after complete correction provided in the embodiment of this application.

[0126] from Figure 8It can be seen that the simulated curves of the first and second voltage signals do not match their expected simulated curves, and are easily interfered with by external magnetic fields, resulting in significant errors in the output signals. In contrast, the corrected first voltage signal Vx (fully corrected) and the corrected first voltage signal Vy (fully corrected) match their expected simulated curves relatively well and are not easily interfered with by external magnetic fields.

[0127] In one possible implementation, the correction unit further includes a sixth correction submodule;

[0128] The sixth correction submodule is used to receive the corrected fourth voltage signal, the corrected fifth voltage signal, and the third voltage signal, and correct the corrected fourth voltage signal, the corrected fifth voltage signal, and the third voltage signal according to the second voltage correction algorithm to obtain the corrected sixth voltage signal.

[0129] In this embodiment, after obtaining the corrected fourth voltage signal and the corrected fifth voltage signal, the sixth correction submodule corrects the corrected fourth voltage signal, the corrected fifth voltage signal, and the third voltage signal according to the second voltage correction algorithm to obtain the corrected sixth voltage signal Vz. out :

[0130]

[0131] In the formula, Vx out and Vy out These are the corrected fourth and fifth voltage signals, respectively, and Vz is the third voltage signal output by the Z-axis sensing unit.

[0132] The Vcc setting should satisfy the following relationship: when Hz = Hsz and Hy = Hx = 0, Vz = Vcc, where Hsz is the saturated magnetic field of the z-axis sensor; VIP is the in-plane magnetic field output voltage, which is obtained by summing the squares of Vxout and Vyout.

[0133] It is understood that this application provides a multi-axis TMR sensor calibration circuit and system. The calibration circuit includes a sensor unit, a voltage signal input terminal, a calibration unit, and a voltage signal output terminal. The voltage signal input terminal is connected to both the sensor unit and the calibration unit, and the voltage signal output terminal is connected to the calibration unit. The sensor unit outputs a voltage signal based on the TMR magnetic sensing characteristics. The voltage signal input terminal receives the voltage signal output by the sensor unit and inputs the uncalibrated voltage signal to the calibration unit. The calibration unit calibrates the uncalibrated voltage signal to obtain a calibrated voltage signal, which is then output through the voltage signal output terminal. Therefore, the sensor unit outputs the original voltage signal based on the TMR magnetic sensing characteristics, i.e., the uncalibrated voltage signal. The calibration unit performs correction calculations on this uncalibrated voltage signal and uses the corrected signal as the output accurate magnetic sensing signal, which is less susceptible to interference from external magnetic fields, thereby improving the accuracy of the output signal.

[0134] join Figure 9 This is a schematic diagram of a multi-axis TMR sensor calibration system provided in an embodiment of this application. The multi-axis TMR sensor calibration system 900 includes a multi-axis TMR sensing module 901, a signal calibration module 903, and a signal transmission module 902. The signal transmission module 902 is connected to both the multi-axis TMR sensing module 901 and the signal calibration module 903. The multi-axis TMR sensing module 901 is used to output a voltage signal based on the TMR magnetic sensing characteristics. The signal calibration module 903 is used to calibrate the voltage signal and output the calibrated voltage signal. The signal transmission module 902 is used to transmit the signal between the multi-axis TMR sensing module and the signal calibration module.

[0135] The multi-axis TMR sensing module consists of two or more independent single-axis TMR sensor units, and each sensing unit has a voltage output terminal.

[0136] As can be seen from the above embodiments, in this application, the original voltage signal is output by the multi-axis TMR sensing module, the signal transmission module transmits the original voltage signal to the signal correction module, the signal correction module performs correction calculations based on the input signal, and uses the corrected signal as the output accurate magnetic sensing signal, which is not easily interfered by external magnetic fields, thus improving the accuracy of the output signal.

[0137] In the embodiments of this application, the terms "first" and "second" (if they exist) are used only as name identifiers and do not represent the order of first and second.

[0138] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0139] Those skilled in the art will understand that the flowchart shown is merely an example in which the embodiments of this application can be implemented, and the scope of application of the embodiments of this application is not limited by any aspect of the flowchart.

[0140] In the several embodiments provided in this application, it should be understood that the disclosed methods, apparatuses, and devices can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual couplings or direct couplings or communication connections may be through some communication interfaces; indirect couplings or communication connections between devices or units may be electrical, mechanical, or other forms.

[0141] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs. Furthermore, the functional units in the various embodiments of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0142] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A multi-axis TMR sensor correction circuit, characterized by, The correction circuit comprises a sensor unit, a voltage signal input end, a correction unit and a voltage signal output end, the voltage signal input end is connected with the sensor unit and the correction unit respectively, and the voltage signal output end is connected with the correction unit; The sensor unit is configured to output a voltage signal based on a TMR magnetic sensing characteristic; The voltage signal input end is configured to receive the voltage signal output by the sensor unit; The correction unit is configured to correct the voltage signal to obtain a corrected voltage signal; The voltage signal output end is configured to output the corrected voltage signal.

2. The correction circuit according to claim 1, characterized in that, The sensor unit comprises an X-axis sensing unit and a Y-axis sensing unit; the X-axis sensing unit is configured to sense a magnetic field in an X-axis direction, and the Y-axis sensing unit is configured to sense a magnetic field in a Y-axis direction; The X-axis sensing unit comprises an x-TMR sensing element and a voltage subtractor; The Y-axis sensing unit comprises a y-TMR sensing element and a voltage subtractor; A first voltage signal output by the X-axis sensing unit is related to a zero-field resistance and a linear coefficient of the x-TMR sensing element; A second voltage signal output by the Y-axis sensing unit is related to a zero-field resistance and a linear coefficient of the y-TMR sensing element.

3. The correction circuit of claim 2, wherein, The sensor unit further comprises a Z-axis sensing unit configured to sense a magnetic field in a Z-axis direction; the Z-axis sensing unit comprises a z-TMR sensing element and a voltage subtractor; A third voltage signal output by the Z-axis sensing unit is related to a zero-field resistance and a linear coefficient of the z-TMR sensing element.

4. The correction circuit of claim 3, wherein, The correction unit comprises a first correction sub-module and a second correction sub-module; The first correction sub-module is configured to receive the first voltage signal, the second voltage signal and a first preset voltage parameter, correct the first voltage signal according to a first voltage correction algorithm, and obtain a corrected first voltage signal; The second correction sub-module is configured to receive the first voltage signal, the second voltage signal and a second preset voltage parameter, correct the second voltage signal according to the first voltage correction algorithm, and obtain a corrected second voltage signal.

5. The correction circuit of claim 4, wherein, The correction unit further comprises a third correction sub-module; The third correction sub-module is configured to receive the corrected first voltage signal, the corrected second voltage signal and the third voltage signal, correct the corrected first voltage signal, the corrected second voltage signal and the third voltage signal according to a second voltage correction algorithm, and obtain a corrected third voltage signal.

6. The correction circuit of claim 3, wherein, The correction unit comprises a fourth correction sub-module and a fifth correction sub-module; The fourth correction sub-module is configured to receive the first voltage signal and the second voltage signal, correct the first voltage signal according to a third voltage correction algorithm, and obtain a corrected fourth voltage signal; The fifth correction sub-module is configured to receive the first voltage signal and the second voltage signal, correct the second voltage signal according to the third voltage correction algorithm, and obtain a corrected fifth voltage signal.

7. The correction circuit of claim 6, wherein, The correction unit further comprises a sixth correction sub-module; The sixth correction submodule is configured to receive the corrected fourth voltage signal, the corrected fifth voltage signal, and the third voltage signal, correct the corrected fourth voltage signal, the corrected fifth voltage signal, and the third voltage signal according to a second voltage correction algorithm, and obtain a corrected sixth voltage signal.

8. The correction circuit according to claim, characterized in that, The correction circuit has at least two or more voltage signal input ends.

9. The correction circuit of claim 1, wherein, The correction unit comprises a voltage operation unit, which is one or more of a voltage adder, a voltage subtractor, a voltage multiplier, and a voltage divider.

10. A multi-axis TMR sensor correction system, characterized by, The system comprises a multi-axis TMR sensing module, a signal correction module, and a signal transmission module, wherein the signal transmission module is connected to the multi-axis TMR sensing module and the signal correction module respectively; The multi-axis TMR sensing module is configured to output a voltage signal based on a TMR magnetic sensing characteristic. The signal correction module is configured to correct the voltage signal and output a corrected voltage signal. The signal transmission module is configured to transmit signals between the multi-axis TMR sensing module and the signal correction module.

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