CN115825826B - Three-axis full-bridge circuit transformation type linear magnetic field sensor - Google Patents
Three-axis full-bridge circuit transformation type linear magnetic field sensor Download PDFInfo
- Publication number
- CN115825826B CN115825826B CN202211656591.9A CN202211656591A CN115825826B CN 115825826 B CN115825826 B CN 115825826B CN 202211656591 A CN202211656591 A CN 202211656591A CN 115825826 B CN115825826 B CN 115825826B
- Authority
- CN
- China
- Prior art keywords
- string structure
- element string
- magnetic field
- sensing element
- magnetoresistive
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 230000005291 magnetic effect Effects 0.000 title claims abstract description 279
- 230000009466 transformation Effects 0.000 title abstract description 14
- 230000004907 flux Effects 0.000 claims description 39
- 230000005415 magnetization Effects 0.000 claims description 19
- 238000003491 array Methods 0.000 claims description 6
- 238000000034 method Methods 0.000 abstract description 13
- 230000008569 process Effects 0.000 abstract description 13
- 238000005259 measurement Methods 0.000 abstract description 11
- 238000013461 design Methods 0.000 abstract description 9
- 238000004519 manufacturing process Methods 0.000 abstract description 5
- 238000012360 testing method Methods 0.000 abstract description 5
- 230000009286 beneficial effect Effects 0.000 abstract description 4
- 238000010586 diagram Methods 0.000 description 13
- 230000005294 ferromagnetic effect Effects 0.000 description 7
- 239000000758 substrate Substances 0.000 description 7
- 238000006243 chemical reaction Methods 0.000 description 5
- 230000000694 effects Effects 0.000 description 4
- 230000005290 antiferromagnetic effect Effects 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 230000005641 tunneling Effects 0.000 description 3
- 230000008859 change Effects 0.000 description 2
- CLOMYZFHNHFSIQ-UHFFFAOYSA-N clonixin Chemical compound CC1=C(Cl)C=CC=C1NC1=NC=CC=C1C(O)=O CLOMYZFHNHFSIQ-UHFFFAOYSA-N 0.000 description 2
- 239000010408 film Substances 0.000 description 2
- 230000035945 sensitivity Effects 0.000 description 2
- 125000006850 spacer group Chemical group 0.000 description 2
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
Landscapes
- Measuring Magnetic Variables (AREA)
Abstract
The application relates to a three-axis full-bridge circuit transformation type linear magnetic field sensor, which comprises two groups of magnetic field sensing units which are mutually perpendicular, wherein each group of magnetic field sensing units comprises a switch circuit and two symmetrically arranged magnetic field sensing array slices, the switch circuit is respectively connected with each magnetic field sensing array slice and is used for switching the conduction state between the two magnetic field sensing array slices to form a changeable bridge structure so as to obtain the three-axis push-pull full-bridge magnetic field sensor, thereby being capable of measuring the magnetic field changes of an X axis, a Y axis and a Z axis, leading the magneto resistor to present obvious linear changes to an external magnetic field in the test process, simultaneously eliminating the measurement errors caused by the magnetic field in the non-sensitive axis direction and improving the measurement precision. In addition, the triaxial full-bridge circuit transformation type linear magnetic field sensor provided by the application adopts a magnetic field sensing array slicing structure, is simple in design and process, reduces the design and process difficulty, and is beneficial to improving the production efficiency and quality.
Description
Technical Field
The application relates to the field of magnetic field sensors, in particular to a three-axis full-bridge circuit transformation type linear magnetic field sensor.
Background
The magnetoresistive sensor reflects an external magnetic field into a distinct low-resistance state or a high-resistance state by using a tunneling magnetoresistance effect (Tunneling magnetoresistance effect, TMR), an anisotropic magnetoresistance effect (Anisotropic magnetoresistance, AMR) or a giant magnetoresistance effect (Giant magnetoresistance, GMR), and achieves a certain magnetic field range by introducing a suitable structure, wherein the magnetoresistance value exhibits a distinct linear change along with the change of the external magnetic field. Compared with the traditional Hall magnetic field sensor, fluxgate sensor and the like, the magnetoresistive sensor has comprehensive advantages in the aspects of sensitivity and miniaturization and microminiaturization, and is widely applied to the fields of integrated magnetic field and current sensing.
However, magnetoresistive sensors based on TMR, GMR, typically have only a single-axis linear sensitivity characteristic in the X-axis, Y-axis or Z-axis, and the signal of the single-axis sensor unit is disturbed by a magnetic field in the non-sensitive axis direction, thereby causing a certain measurement error.
Disclosure of Invention
In view of the foregoing, it is desirable to provide a three-axis full-bridge circuit-switching type linear magnetic field sensor.
The embodiment of the application provides a three-axis full-bridge circuit transformation type linear magnetic field sensor, which comprises: the two groups of magnetic field sensing units are arranged vertically, each group of magnetic field sensing units comprises a switch circuit and two symmetrically arranged magnetic field sensing array slices, and the switch circuits are respectively connected with the magnetic field sensing array slices and are used for switching the conduction state between the two magnetic field sensing array slices; wherein each of the magnetic field sensing array slices comprises:
two magnetic field sensing arrays, each for sensing a magnetic field;
and the magnetic flux control module is positioned above each magnetic field sensing array.
In one embodiment, each of the magnetic field sensing arrays includes two magnetoresistive sensing element string structures disposed parallel to each other, each of the magnetoresistive sensing element string structures including at least one row of magnetoresistive sensing element strings electrically connected to each other.
In one embodiment, the string of magneto-resistive sensing elements comprises a plurality of interconnected magneto-resistive sensing elements.
In one embodiment, each of the magneto-resistive sensing elements is an elliptical or rectangular magneto-resistive sensing element, wherein a short axis direction of each of the magneto-resistive sensing elements is a magnetization direction of the pinned layer and is parallel to a short axis direction of the magnetic flux control module, and a long axis direction of each of the magneto-resistive sensing elements is perpendicular to the magnetization direction of the pinned layer and is parallel to a long axis direction of the magnetic flux control module.
In one embodiment, the magnetization direction of the magnetic free layer of each of the magnetoresistive sensor elements is parallel to the long axis direction of the magnetoresistive sensor element in the absence of an external magnetic field.
In one embodiment, the magnetic flux control modules are of rectangular strip structures, the long side direction of each magnetic flux control module is perpendicular to the magnetization direction of the pinning layer of the magnetoresistive sensor element, the short side direction of each magnetic flux control module is parallel to the magnetization direction of the pinning layer of the magnetoresistive sensor element, each magnetic flux control module is arranged along the short side direction, and a gap is reserved between two adjacent magnetic flux control modules; the magnetic resistance sensing element strings adjacent to each other in every two rows are positioned below the magnetic flux control module and are equidistantly arranged along the long side direction of the magnetic flux control module.
In one embodiment, each of the magnetic field sensing units comprises a first magnetic field sensing array slice and a second magnetic field sensing array slice; the first magnetic field sensing array slice comprises a first magnetic resistance sensing element string structure, a second magnetic resistance sensing element string structure, a third magnetic resistance sensing element string structure and a fourth magnetic resistance sensing element string structure; the second magnetic field sensing array slice comprises a fifth magnetic resistance sensing element string structure, a sixth magnetic resistance sensing element string structure, a seventh magnetic resistance sensing element string structure and an eighth magnetic resistance sensing element string structure; wherein,,
the first magneto-resistive sensing element string structure and the fifth magneto-resistive sensing element string structure are centrosymmetric, the second magneto-resistive sensing element string structure and the sixth magneto-resistive sensing element string structure are centrosymmetric, the third magneto-resistive sensing element string structure and the seventh magneto-resistive sensing element string structure are centrosymmetric, and the fourth magneto-resistive sensing element string structure and the eighth magneto-resistive sensing element string structure are centrosymmetric.
In one embodiment, the switching circuit is controlled such that the first end of the first magnetoresistive sensing element string structure is connected to the second end of the fifth magnetoresistive sensing element string structure, the first end of the second magnetoresistive sensing element string structure is connected to the second end of the sixth magnetoresistive sensing element string structure, the first end of the third magnetoresistive sensing element string structure is connected to the second end of the seventh magnetoresistive sensing element string structure, the first end of the fourth magnetoresistive sensing element string structure is connected to the second end of the eighth magnetoresistive sensing element string structure, the second end of the first magnetoresistive sensing element string structure and the second end of the fourth magnetoresistive sensing element string structure are both connected to a bias voltage, the second end of the second magnetoresistive sensing element string structure and the second end of the third magnetoresistive sensing element string structure are both grounded, the first end of the fifth magnetoresistive sensing element string structure and the first end of the sixth magnetoresistive sensing element string structure are both connected to the first output end, the first end of the seventh magnetoresistive sensing element string structure and the first end of the fourth magnetoresistive sensing element string structure are both connected to the second end of the fourth magnetoresistive sensing element string structure, and the first end of the second magnetoresistive sensing element string structure is the Z-axis direction is measured.
In one embodiment, the switching circuit is controlled such that the first end of the first magnetoresistive sensing element string structure is connected to the first end of the second magnetoresistive sensing element string structure, the second end of the fifth magnetoresistive sensing element string structure is connected to the second end of the sixth magnetoresistive sensing element string structure, the second end of the third magnetoresistive sensing element string structure is connected to the second end of the fourth magnetoresistive sensing element string structure, the first end of the seventh magnetoresistive sensing element string structure is connected to the first end of the eighth magnetoresistive sensing element string structure, the second end of the first magnetoresistive sensing element string structure and the second end of the seventh magnetoresistive sensing element string structure are both connected to a bias voltage, the first end of the third magnetoresistive sensing element string structure and the first end of the fifth magnetoresistive sensing element string structure are both grounded, the second end of the second magnetoresistive sensing element string structure and the first end of the sixth magnetoresistive sensing element string structure are both connected to and are both first output ends, the second end of the fourth magnetoresistive sensing element string structure and the second end of the fourth magnetoresistive sensing element string structure are both connected to the second output ends of the fourth magnetoresistive sensing element string structure or the second output ends of the fourth magnetoresistive sensing element string structure.
In one embodiment, the output voltage v= (R1-R2) Vbias/(r1+r2) between the first output terminal and the second output terminal; wherein R1 represents an equivalent resistance of the first magnetoresistive sensing element string structure or the third magnetoresistive sensing element string structure, R2 represents an equivalent resistance of the second magnetoresistive sensing element string structure or the fourth magnetoresistive sensing element string structure, and Vbias represents the bias voltage.
The three-axis full-bridge circuit conversion type linear magnetic field sensor provided by the embodiment comprises two groups of magnetic field sensing units which are arranged vertically to each other, each group of magnetic field sensing units comprises a switch circuit and two magnetic field sensing array slices which are symmetrically arranged, the switch circuit is respectively connected with each magnetic field sensing array slice and is used for switching the conduction state between the two magnetic field sensing array slices to form a changeable bridge structure so as to obtain the three-axis push-pull full-bridge magnetic field sensor, thereby being capable of measuring the magnetic field changes of an X axis, a Y axis and a Z axis, enabling the magneto resistor to present obvious linear changes to an external magnetic field in the test process, simultaneously eliminating measurement errors caused by magnetic fields in the non-sensitive axis direction and improving the measurement precision. In addition, the triaxial full-bridge circuit transformation type linear magnetic field sensor provided by the application adopts a magnetic field sensing array slicing structure, is simple in design and process, reduces the design and process difficulty, and is beneficial to improving the production efficiency and quality.
Drawings
FIG. 1 is a schematic diagram of a three-axis full-bridge circuit transformation type linear magnetic field sensor according to an embodiment;
FIG. 2 is a schematic diagram of a magnetic field sensing array according to one embodiment;
FIG. 3 is a schematic diagram of a magnetic field sensing unit according to an embodiment;
FIG. 4 is a schematic diagram of a three-axis full-bridge circuit transformation type linear magnetic field sensor according to another embodiment;
FIG. 5 is a schematic diagram of a switch circuit according to an embodiment;
FIG. 6 is a schematic diagram of a circuit connection relationship of a magnetic field sensing unit according to an embodiment;
FIG. 7 is an equivalent circuit diagram of the circuit of FIG. 6 provided in one embodiment;
FIG. 8 is a schematic diagram of a magnetic field around a magnetoresistive sensing element provided by one embodiment;
FIG. 9 is a schematic diagram of the resistance versus magnetic field of a magnetoresistive sensing element according to one embodiment;
FIG. 10 is a schematic diagram showing a circuit connection relationship of a magnetic field sensing unit according to another embodiment;
FIG. 11 is an equivalent circuit diagram of the circuit of FIG. 10 provided in one embodiment;
FIG. 12 is a schematic diagram of a magnetic field around a magnetoresistive sensing element according to another embodiment.
Detailed Description
The present application will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present application more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the application.
As the background technology is adopted, in order to realize three-axis detection and improve measurement accuracy, the application provides a three-axis full-bridge circuit transformation type linear magnetic field sensor.
In one embodiment, referring to FIG. 1, a three-axis full-bridge circuit transformed linear magnetic field sensor is provided. The three-axis full-bridge circuit transformation type linear magnetic field sensor comprises two groups of magnetic field sensing units 10 which are mutually perpendicular. For example, one set of magnetic field sensing units 10 may be rotated 90 degrees in the X-Y plane to obtain another set of magnetic field sensing units 10. Each set of magnetic field sensing units 10 comprises a switching circuit 110 and two symmetrically arranged magnetic field sensing array slices 120. The switch circuits 110 are respectively connected to the magnetic field sensing array slices 120, and the switch circuits 110 are used for switching the conduction state between the two magnetic field sensing array slices 120. Wherein each magnetic field sensing array slice 120 has the same structure and comprises two magnetic field sensing arrays 121 and a magnetic flux control module 122. Each magnetic field sensing array 121 is for sensing a magnetic field. A magnetic flux control module 122 is located above each magnetic field sensing array 121, the magnetic flux control module 122 may be used to adjust the direction and magnitude of the magnetic field, and the magnetic flux control module 122 may be a magnetic flux controller. Illustratively, each magnetic field sensing array slice 120 may also include a substrate 123, and each magnetic field sensing array 121 may be deposited on the substrate 123. Illustratively, the substrate 123 may be a silicon single crystal substrate or other general-purpose electronic component substrate.
According to the three-axis full-bridge circuit conversion type linear magnetic field sensor, the switching circuit is used for switching the conduction state between the two magnetic field sensing array slices to form a changeable bridge structure, so that the three-axis push-pull type full-bridge magnetic field sensor is obtained, the magnetic field changes of an in-plane X axis, a Y axis and an out-of-plane Z axis can be measured, the magnetic resistance shows obvious linear changes on an external magnetic field in the test process, meanwhile, the measurement error caused by a non-sensitive axis magnetic field can be eliminated, and the measurement accuracy is improved. In addition, the triaxial full-bridge circuit transformation type linear magnetic field sensor adopts a magnetic field sensing array slicing structure, is simple in design and process, reduces design and process difficulty, and is beneficial to improving production efficiency and quality.
In one embodiment, referring to fig. 2, each magnetic field sensing array 121 includes two magneto-resistive sensing element string structures 1210 disposed parallel to each other, wherein two ends of one magneto-resistive sensing element string structure 1210 are electrically connected to pads 11 and 13, respectively, and two ends of the other magneto-resistive sensing element string structure 1210 are electrically connected to pads 12 and 14, respectively. Each magnetoresistive sensing element string structure 1210 includes at least one row of magnetoresistive sensing element strings 1211 electrically connected to each other, each row of magnetoresistive sensing element strings 1211 being aligned along the Y-axis direction in fig. 2.
In the three-axis full-bridge circuit conversion type linear magnetic field sensor, each magnetic field sensing array 121 is composed of at least one row of magnetic resistance sensing element strings 1211 which are electrically connected with each other, and a variable bridge structure is formed by combining the switch circuit 110, so that the three-axis push-pull type full-bridge magnetic field sensor is obtained, and the magnetic field changes of an in-plane X axis, a Y axis and an out-of-plane Z axis can be measured, so that the magnetic resistance presents obvious linear changes to an external magnetic field in the testing process, and meanwhile, the measuring error caused by a magnetic field in a non-sensitive axis direction can be eliminated, the measuring precision is improved, the design and the process are simple, and the production efficiency and the quality are improved.
In one embodiment, referring still to FIG. 2, each magnetoresistive sensing element string 1211 may include a plurality of interconnected magnetoresistive sensing elements 1211a. Each magnetoresistive sensing element string 1211 may also include one magnetoresistive sensing element 1211a. Illustratively, each magnetoresistive sensing element 1211a may be a TMR magnetoresistive sensing element or a GMR magnetoresistive sensing element.
In the three-axis full-bridge circuit conversion type linear magnetic field sensor, each magnetic resistance sensing element string 1211 is composed of one or a plurality of magnetic resistance sensing elements 1211a which are electrically connected with each other, and a variable bridge structure is formed by combining the switch circuit 110, so that the three-axis push-pull type full-bridge magnetic field sensor is obtained, and the magnetic field changes of an in-plane X axis, a Y axis and an out-of-plane Z axis can be measured, so that the magnetic resistance shows obvious linear changes on an external magnetic field in the test process, and meanwhile, measurement errors caused by a magnetic field in a non-sensitive axis direction can be eliminated, the measurement precision is improved, and the design and the process are simple, thereby being beneficial to improving the production efficiency and the quality.
In one embodiment, each magnetoresistive sensing element 1211a may be an elliptical or rectangular magnetoresistive sensing element, and the magnetoresistive sensing element 1211a shown in FIG. 2 is an elliptical shape. The short axis direction of each magnetoresistive sensor element 1211a is the magnetization direction of the pinned layer, and is parallel to the short side direction of the magnetic flux control module 122, and the long axis direction of each magnetoresistive sensor element 1211a is perpendicular to the magnetization direction of the pinned layer, and is parallel to the long side direction of the magnetic flux control module 122.
In the three-axis full-bridge circuit transformation type linear magnetic field sensor, each magneto-resistive sensing element 1211a may have an elliptical shape or a rectangular shape, thereby increasing design diversity and realizability, and sensing three-axis magnetic field variation by setting the position direction of each magneto-resistive sensing element 1211a.
In one embodiment, each magnetoresistive sensing element 1211a includes a magnetic tunnel junction multilayer film structure. The magnetic tunnel junction multilayer thin film structure may include, from top to bottom, an antiferromagnetic layer, a pinning layer, a ferromagnetic reference layer, a metal spacer layer, a ferromagnetic reference layer, an insulating layer tunneling layer, and a ferromagnetic free layer, or an antiferromagnetic layer, a pinning layer, a ferromagnetic reference layer, a metal spacer layer, a ferromagnetic reference layer, a nonmagnetic metal layer, and a ferromagnetic free layer.
In the three-axis full-bridge circuit transformation type linear magnetic field sensor, each of the magneto-resistive sensing elements 1211a has a magnetic tunnel junction multilayer film structure, thereby realizing sensing of three-axis magnetic field variation.
In one embodiment, the magnetization direction of the magnetic free layer of each magnetoresistive sensor element 1211a is parallel to the long axis direction of magnetoresistive sensor element 1211a in the absence of an external magnetic field to sense magnetic fields in different directions. Illustratively, the magnetoresistive sensing unit 10 may be annealed at the blocking temperature of the antiferromagnetic layer, with the pinning direction of the reference layer being parallel to the short axis direction of the magnetoresistive sensing element 1211a by applying a magnetic field along the short axis direction of the magnetoresistive sensing element 1211a during cooling.
In one embodiment, with continued reference to FIG. 2, the flux control modules 122 may be rectangular elongated structures, with the long side direction of the flux control modules 122 being perpendicular to the magnetization direction of the pinned layer of the magnetoresistive sensor element 1211a and the short side direction of the flux control modules 122 being parallel to the magnetization direction of the pinned layer of the magnetoresistive sensor element 1211a, each flux control module 122 being aligned along the short side direction with a gap between adjacent two flux control modules 122. Wherein, every two adjacent rows of the magnetic resistance sensing element strings 1211 are positioned below the magnetic flux control module 122 and are equidistantly arranged along the long side direction of the magnetic flux control module 122. In one embodiment, the material of the rectangular elongated structure of the magnetic flux control module 122 is a soft ferromagnetic alloy.
In the three-axis full-bridge circuit conversion type linear magnetic field sensor, the magnetic flux control module 122 is configured to have a rectangular strip structure and is covered above the magnetic resistance sensing element string 1211 so as to adjust the direction and the size of the magnetic field, thereby sensing the magnetic field by using the magnetic resistance sensing element 1211a and realizing the measurement of the three-axis magnetic field.
For a better understanding, a single magnetic field sensing array slice 120 is described with reference to FIG. 3 in conjunction with the magnetic field sensing array 121 shown in FIG. 2. As shown in fig. 3, the magnetic field sensing array slice 120 includes a substrate 123, two magnetic field sensing arrays 121 deposited on the substrate 123, a magnetic flux control module 122, and 8 pads 11-18. The specific structure of the magnetic field sensing array 121 can be seen in fig. 2 and related content, and will not be described herein.
In one embodiment, referring to fig. 4, the magnetoresistive sensing element string structure includes three rows of magnetoresistive sensing element strings, and the magnetoresistive sensing element string includes eight elliptical magnetoresistive sensor elements as an example. Each magnetic field sensing unit includes a first magnetic field sensing array slice and a second magnetic field sensing array slice. The first magnetic field sensing array slice comprises a first magnetic resistance sensing element string structure, a second magnetic resistance sensing element string structure, a third magnetic resistance sensing element string structure and a fourth magnetic resistance sensing element string structure. The second magnetic field sensing array slice includes a fifth magnetoresistive sensing element string structure, a sixth magnetoresistive sensing element string structure, a seventh magnetoresistive sensing element string structure, and an eighth magnetoresistive sensing element string structure.
Wherein, two ends of the first magneto-resistive sensing element string structure are respectively connected with the bonding pad 16 and the bonding pad 18; two ends of the second magnetic resistance sensing element string structure are respectively connected with the bonding pad 15 and the bonding pad 17; two ends of the third magnetic resistance sensing element string structure are respectively connected with the bonding pad 12 and the bonding pad 14; two ends of the fourth magnetic resistance sensing element string structure are respectively connected with the bonding pad 11 and the bonding pad 13; two ends of the fifth magneto-resistive sensing element string structure are respectively connected with the bonding pads 16 'and 18'; two ends of the sixth magneto-resistive sensing element string structure are respectively connected with the bonding pads 15 'and 17'; two ends of the seventh magnetic resistance sensing element string structure are respectively connected with the bonding pads 12 'and 14'; both ends of the eighth magnetoresistive sensing element string structure are connected to the pads 11', 13', respectively.
The first magnetic resistance sensing element string structure and the fifth magnetic resistance sensing element string structure are symmetrical in center, the second magnetic resistance sensing element string structure and the sixth magnetic resistance sensing element string structure are symmetrical in center, the third magnetic resistance sensing element string structure and the seventh magnetic resistance sensing element string structure are symmetrical in center, and the fourth magnetic resistance sensing element string structure and the eighth magnetic resistance sensing element string structure are symmetrical in center.
In one embodiment, please continue to refer to fig. 4, and refer to fig. 5 and 6. The switch circuit 110 shown in fig. 5 is connected to the pads shown in fig. 4 in a one-to-one correspondence, and the switch circuit may include 16 MOS transistors, a supply bias voltage input terminal VDD, a ground terminal GND, an output V1 terminal, an output V2 terminal, and level control S1 and S2 terminals. Fig. 6 shows a diagram of the circuit connection between two magnetic field sensing array slices in the magnetic field sensing unit shown in fig. 4.
Specifically, the switching circuit may be controlled to connect a first end of the first magnetoresistive sensing element string structure (i.e., pad 16) with a second end of the fifth magnetoresistive sensing element string structure (i.e., pad 18'), i.e., to connect pad 26 and pad 36; connecting a first end of the second magnetoresistive sensing element string structure (i.e., pad 15) with a second end of the sixth magnetoresistive sensing element string structure (i.e., pad 17'), namely connecting pad 25 and pad 35; connecting a first end of the third magnetoresistive sensing element string structure (i.e., pad 12) with a second end of the seventh magnetoresistive sensing element string structure (i.e., pad 14'), i.e., connecting pad 22 and pad 32; connecting a first end of the fourth magnetoresistive sensing element string structure (i.e., pad 11) with a second end of the eighth magnetoresistive sensing element string structure (i.e., pad 13'), i.e., connecting pad 21 and pad 31; connecting both the second end of the first magnetoresistive sensing element string structure (i.e., pad 18) and the second end of the fourth magnetoresistive sensing element string structure (i.e., pad 23) to a bias voltage Vbias, i.e., pad 27 to pad 24 to a bias voltage vbas; grounding both the second end of the second magnetoresistive sensing element string structure (i.e., pad 17) and the second end of the third magnetoresistive sensing element string structure (i.e., pad 14), i.e., pad 28 and pad 23 to ground GND; connecting a first end of the fifth magnetoresistive sensing element string structure (i.e., pad 16 ') and a first end of the sixth magnetoresistive sensing element string structure (i.e., pad 15') and being a first output terminal V1, i.e., pad 37 is connected to pad 38 and being a first output terminal V1; the first end of the seventh magnetoresistive sensing element string structure (i.e., pad 12 ') and the first end of the eighth magnetoresistive sensing element string structure (i.e., pad 11') are connected and are the second output terminal V2, i.e., pad 33 is connected with pad 34 and is the second output terminal V2, to measure the Z-axis direction magnetic field.
The equivalent circuit of the connection shown in fig. 4 and fig. 6 is shown in fig. 7, wherein the first magneto-resistive sensing element string structure and the fifth magneto-resistive sensing element string structure form a first push arm, the second magneto-resistive sensing element string structure and the sixth magneto-resistive sensing element string structure form a first pull arm, the third magneto-resistive sensing element string structure and the seventh magneto-resistive sensing element string structure form a second push arm, and the fourth magneto-resistive sensing element string structure and the eighth magneto-resistive sensing element string structure form a second pull arm.
When the external magnetic field direction is the Z direction, the magnetic flux control module regulates the magnetic field direction and the magnetic field intensity, the magnetic field around the magnetic resistance sensing element is shown in fig. 8, and the arrow direction in the figure is the magnetic induction line direction. The magnetic fields actually induced by the magnetic resistance sensing element strings positioned at two sides below the same magnetic flux control module respectively form a push arm and a pull arm along the +X direction and the-X direction, a magnetic resistance sensor in the push arm is in a high resistance state R1, and a magnetic resistance sensor in the pull arm is in a low resistance state R2. Ideally the push-pull full-bridge output voltage shown in fig. 7 is:
wherein V represents an output voltage between the first output terminal and the second output terminal; v1 represents a first output terminal; v2 represents a second output terminal; vbias represents the bias voltage; r1 represents the equivalent resistance of the first push arm or the second push arm; r2 represents the equivalent resistance of the first or second arm.
When the magnetic field in the X-axis direction exists, an interference magnetic field along the X-axis direction exists in the space, and causes the corresponding resistances R1 and R2 of the push arm and the pull arm to decrease or increase by Δr, as shown in fig. 9, wherein the abscissa H represents the magnetic field, the ordinate R represents the resistance, B1 represents the negative saturation magnetic field, B2 represents the positive saturation magnetic field, RL represents the minimum resistance of the magnetic tunnel junction when the magnetic field and the pinning direction of the pinning layer are parallel, and RH represents the maximum resistance of the magnetic tunnel junction when the magnetic field and the pinning direction of the pinning layer are perpendicular.
If the magnetic field is opposite to the magnetization direction of the pinning layer of the left magneto-resistance sensor, the magneto-resistance in the first push arm is R1+ [ delta ] R, and the magneto-resistance in the first pull arm is R2+ [ delta ] R; the magnetization direction of the pinned layer of the second push arm is the same as that of the right magnetic resistance sensor, and the magnetic resistance in the second push arm is R1-DeltaR, and the magnetic resistance in the second pull arm is R2-DeltaR. The push-pull full-bridge output voltage is:
if the magnetic field is the same as the magnetization direction of the pinning layer of the left magneto-resistance sensor, the magneto-resistance in the first push arm is R1-DeltaR, and the magneto-resistance in the first pull arm is R2-DeltaR; the magnetoresistance in the second push arm is r1+ [ DELTA ] R and the magnetoresistance in the second pull arm is r2+ [ DELTA ] R, opposite to the magnetization direction of the pinned layer of the right magnetoresistive sensor. The push-pull full-bridge output voltage at this time is:
the voltage output value is the same as the voltage output when only the magnetic field in the z-axis direction exists, and no in-plane direction error exists, so that the push-pull type full-bridge magnetic field sensor provided by the application can eliminate the error caused by the in-plane magnetic field when the out-of-plane magnetic field is tested.
In one embodiment, with continued reference to fig. 4 and 5, and with reference to fig. 10, the switching circuit is controlled to connect the first end of the first magnetoresistive sensing element string structure (i.e., pad 16) with the first end of the second magnetoresistive sensing element string structure (i.e., pad 15), i.e., to connect pad 26 with pad 25; connecting a second end of the fifth magnetoresistive sensing element string structure (i.e., pad 18 ') with a second end of the sixth magnetoresistive sensing element string structure (i.e., pad 17'), i.e., connecting pad 36 with pad 35; connecting a second end of the third magnetoresistive sensing element string structure (i.e., pad 14) with a second end of the fourth magnetoresistive sensing element string structure (i.e., pad 13), i.e., connecting pad 23 with pad 24; connecting a first end of the seventh magnetoresistive sensing element string structure (i.e., pad 12 ') with a first end of the eighth magnetoresistive sensing element string structure (i.e., pad 11'), i.e., connecting pad 33 with pad 34; connecting both the second end of the first magnetoresistive sensing element string structure (i.e., pad 18) and the second end of the seventh magnetoresistive sensing element string structure (i.e., pad 14') to the bias voltage Vbias, i.e., pad 27 to pad 32; grounding both the first end of the third magnetoresistive sensing element string structure (i.e., pad 12) and the first end of the fifth magnetoresistive sensing element string structure (i.e., pad 16'), i.e., both pad 22 and pad 37 are grounded GND; connecting the second end of the second magnetoresistive sensing element string structure (i.e., pad 17) with the first end of the sixth magnetoresistive sensing element string structure (i.e., pad 15') and being the first output terminal V1, i.e., pad 28 is connected with pad 38 and being the first output terminal V1; the first end of the fourth magnetoresistive sensing element string structure (i.e., pad 11) and the second end of the eighth magnetoresistive sensing element string structure (i.e., pad 13') are connected and are the second output terminal V2, i.e., pad 21 is connected with pad 31 and is the second output terminal V2, to measure the X-axis or Y-axis magnetic field.
The equivalent circuit of the connection shown in fig. 4 and fig. 10 is shown in fig. 11, wherein the first magneto-resistive sensing element string structure and the second magneto-resistive sensing element string structure form a first push arm, the fifth magneto-resistive sensing element string structure and the sixth magneto-resistive sensing element string structure form a first pull arm, the third magneto-resistive sensing element string structure and the fourth magneto-resistive sensing element string structure form a second push arm, and the seventh magneto-resistive sensing element string structure and the eighth magneto-resistive sensing element string structure form a second pull arm.
When the external magnetic field direction is the X direction, the magnetic field around the magneto-resistive sensing element is as shown in fig. 12, and the push-pull full-bridge output voltage is ideally:
when an additional Z-axis magnetic field exists, the magnetic resistances of the two rows of magnetic resistance sensing element strings in the first pushing arm and the second pushing arm are R1-DeltaR and R1+ DeltaRrespectively, and the magnetic resistances of the two rows of magnetic resistance sensing element strings in the first pulling arm and the second pulling arm are R2-DeltaR and R2+ DeltaRrespectively. The push-pull full-bridge output voltage is:
the voltage output value is the same as the voltage output when only the X-axis magnetic field exists, and other direction errors are avoided.
When the external magnetic field direction is the Y direction, the push-pull full-bridge output voltage is as follows:
when an additional Z-axis magnetic field exists, the magnetic resistances of the two rows of magnetic resistance sensing element strings in the first push arm and the second push arm are R1-DeltaR-DeltaRz and R1+ DeltaR+ DeltaRzrespectively, and the magnetic resistances of the two rows of magnetic resistance sensing element strings in the first pull arm and the second pull arm are R2-DeltaR-DeltaRz and R2+ DeltaR+ DeltaRzrespectively. The push-pull full-bridge output voltage is:
the voltage output value is the same as the voltage output when only the Y-axis magnetic field exists, and other direction errors are avoided.
The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.
The above examples illustrate only a few embodiments of the application, which are described in detail and are not to be construed as limiting the scope of the application. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the application, which are all within the scope of the application. Accordingly, the scope of protection of the present application is to be determined by the appended claims.
Claims (10)
1. A three-axis full-bridge circuit transformed linear magnetic field sensor, comprising: two groups of magnetic field sensing units which are arranged vertically to each other, wherein one group of magnetic field sensing units is obtained by rotating the other group of magnetic field sensing units by 90 degrees in an X-Y plane, each group of magnetic field sensing units comprises a switch circuit and two symmetrically arranged magnetic field sensing array slices, and the switch circuits are respectively connected with each magnetic field sensing array slice and are used for switching the conduction state between the two magnetic field sensing array slices to form a changeable bridge structure so as to obtain the triaxial push-pull type full-bridge magnetic field sensor; wherein each of the magnetic field sensing array slices comprises:
two magnetic field sensing arrays, each for sensing a magnetic field;
and the magnetic flux control module is positioned above each magnetic field sensing array.
2. The three-axis full-bridge circuit transformed linear magnetic field sensor of claim 1, wherein each of the magnetic field sensing arrays comprises two magnetoresistive sensing element string structures disposed parallel to each other, each of the magnetoresistive sensing element string structures comprising at least one row of magnetoresistive sensing element strings electrically connected to each other.
3. The three-axis full-bridge circuit transformed linear magnetic field sensor of claim 2, wherein the string of magneto-resistive sensing elements comprises a plurality of interconnected magneto-resistive sensing elements.
4. The three-axis full-bridge circuit-transformed linear magnetic field sensor according to claim 3, wherein each of the magneto-resistive sensing elements is an elliptical or rectangular magneto-resistive sensing element, wherein a short axis direction of each of the magneto-resistive sensing elements is a magnetization direction of the pinned layer, parallel to a short axis direction of the magnetic flux control module, and a long axis direction of each of the magneto-resistive sensing elements is perpendicular to the magnetization direction of the pinned layer, parallel to a long axis direction of the magnetic flux control module.
5. The three-axis full-bridge circuit-transformed linear magnetic field sensor according to claim 4, wherein the magnetization direction of the magnetic free layer of each of the magneto-resistive sensing elements is parallel to the long axis direction of the magneto-resistive sensing element in the absence of an external magnetic field.
6. The three-axis full-bridge circuit transformed linear magnetic field sensor according to claim 2, wherein the magnetic flux control modules have a rectangular strip structure, the long side direction of the magnetic flux control modules is perpendicular to the magnetization direction of the pinned layer of the magneto-resistive sensing element, the short side direction of the magnetic flux control modules is parallel to the magnetization direction of the pinned layer of the magneto-resistive sensing element, each of the magnetic flux control modules is arranged along the short side direction with a gap between two adjacent magnetic flux control modules; wherein,,
every two adjacent magnetic resistance sensing element strings are positioned below the magnetic flux control module and are equidistantly arranged along the long side direction of the magnetic flux control module.
7. The three-axis full-bridge circuit transformed linear magnetic field sensor of claim 1, wherein each of the magnetic field sensing units comprises a first magnetic field sensing array slice and a second magnetic field sensing array slice; the first magnetic field sensing array slice comprises a first magnetic resistance sensing element string structure, a second magnetic resistance sensing element string structure, a third magnetic resistance sensing element string structure and a fourth magnetic resistance sensing element string structure; the second magnetic field sensing array slice comprises a fifth magnetic resistance sensing element string structure, a sixth magnetic resistance sensing element string structure, a seventh magnetic resistance sensing element string structure and an eighth magnetic resistance sensing element string structure; wherein,,
the first magneto-resistive sensing element string structure and the fifth magneto-resistive sensing element string structure are centrosymmetric, the second magneto-resistive sensing element string structure and the sixth magneto-resistive sensing element string structure are centrosymmetric, the third magneto-resistive sensing element string structure and the seventh magneto-resistive sensing element string structure are centrosymmetric, and the fourth magneto-resistive sensing element string structure and the eighth magneto-resistive sensing element string structure are centrosymmetric.
8. The three-axis full-bridge circuit-switched linear magnetic field sensor according to claim 7, wherein the switching circuit is controlled such that a first end of the first magnetoresistive sensing element string structure is connected to a second end of the fifth magnetoresistive sensing element string structure, the first end of the second magnetoresistive sensing element string structure is connected to a second end of the sixth magnetoresistive sensing element string structure, the first end of the third magnetoresistive sensing element string structure is connected to a second end of the seventh magnetoresistive sensing element string structure, the first end of the fourth magnetoresistive sensing element string structure is connected to a second end of the eighth magnetoresistive sensing element string structure, the second end of the first magnetoresistive sensing element string structure and the second end of the fourth magnetoresistive sensing element string structure are both connected to a bias voltage, the second end of the second magnetoresistive sensing element string structure and the second end of the third magnetoresistive sensing element string structure are both grounded, the first end of the fifth magnetoresistive sensing element string structure and the first end of the sixth magnetoresistive sensing element string structure are connected to the second end of the seventh magnetoresistive sensing element string structure, the first end of the fourth magnetoresistive sensing element string structure is connected to the first end of the seventh magnetoresistive sensing element string structure, and the first end of the fourth magnetoresistive sensing element string structure is connected to the first end of the Z-axis sensing element string is connected to the first end of the Z-axis sensing element.
9. The three-axis full-bridge circuit-switched linear magnetic field sensor according to claim 7, wherein the switching circuit is controlled such that a first end of the first magnetoresistive sensor element string structure is connected to a first end of the second magnetoresistive sensor element string structure, a second end of the fifth magnetoresistive sensor element string structure is connected to a second end of the sixth magnetoresistive sensor element string structure, a second end of the third magnetoresistive sensor element string structure is connected to a second end of the fourth magnetoresistive sensor element string structure, a first end of the seventh magnetoresistive sensor element string structure is connected to a first end of the eighth magnetoresistive sensor element string structure, both the second end of the first magnetoresistive sensor element string structure and the second end of the seventh magnetoresistive sensor element string structure are connected to a bias voltage, both the first end of the third magnetoresistive sensor element string structure and the first end of the fifth magnetoresistive sensor element string structure are grounded, both the second end of the second magnetoresistive sensor element string structure and the first end of the sixth magnetoresistive sensor element string structure are connected to a second end of the fourth magnetoresistive sensor element string structure, the first end of the seventh magnetoresistive sensor element string structure and the second end of the fourth magnetoresistive sensor element string structure are connected to a first end of the fourth magnetoresistive sensor element string structure, and the first magnetoresistive sensor element string structure is connected to a second end of the fourth magnetoresistive sensor element string structure, and the second magnetoresistive sensor element is connected to a second end of the fourth magnetoresistive sensor element string structure.
10. The three-axis full-bridge circuit transformed linear magnetic field sensor according to claim 8 or 9, wherein the output voltage v= (R1-R2) Vbias/(r1+r2) between the first output terminal and the second output terminal; wherein R1 represents an equivalent resistance of the first magnetoresistive sensing element string structure or the third magnetoresistive sensing element string structure, R2 represents an equivalent resistance of the second magnetoresistive sensing element string structure or the fourth magnetoresistive sensing element string structure, and Vbias represents the bias voltage.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211656591.9A CN115825826B (en) | 2022-12-22 | 2022-12-22 | Three-axis full-bridge circuit transformation type linear magnetic field sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211656591.9A CN115825826B (en) | 2022-12-22 | 2022-12-22 | Three-axis full-bridge circuit transformation type linear magnetic field sensor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115825826A CN115825826A (en) | 2023-03-21 |
| CN115825826B true CN115825826B (en) | 2023-09-15 |
Family
ID=85517705
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211656591.9A Active CN115825826B (en) | 2022-12-22 | 2022-12-22 | Three-axis full-bridge circuit transformation type linear magnetic field sensor |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115825826B (en) |
Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006010579A (en) * | 2004-06-28 | 2006-01-12 | Yamaha Corp | Magnetic sensor |
| CN102426344A (en) * | 2011-08-30 | 2012-04-25 | 江苏多维科技有限公司 | Triaxial magnetic field sensor |
| CN103913709A (en) * | 2014-03-28 | 2014-07-09 | 江苏多维科技有限公司 | Single-chip three-axis magnetic field sensor and manufacturing method thereof |
| CN104280700A (en) * | 2014-09-28 | 2015-01-14 | 江苏多维科技有限公司 | Single chip difference free layer push-pull type magnetic field sensor electric bridge and preparation method thereof |
| CN104776794A (en) * | 2015-04-16 | 2015-07-15 | 江苏多维科技有限公司 | Separately-encapsulated high-intensity magnetic-field magneto-resistance angle sensor |
| CN105044631A (en) * | 2015-08-28 | 2015-11-11 | 江苏多维科技有限公司 | Half turning-over dual axle magneto resistance sensor |
| CN105093139A (en) * | 2015-06-09 | 2015-11-25 | 江苏多维科技有限公司 | Push-pull X shaft magneto-resistor sensor |
| CN206671519U (en) * | 2017-03-24 | 2017-11-24 | 江苏多维科技有限公司 | A kind of single-chip twin shaft magneto-resistor linear transducer |
| CN108413992A (en) * | 2018-01-30 | 2018-08-17 | 江苏多维科技有限公司 | A kind of three axis premodulated low noise magnetic resistance sensors |
| CN110794348A (en) * | 2018-08-03 | 2020-02-14 | 爱盛科技股份有限公司 | Magnetic field sensing device |
| CN111413653A (en) * | 2019-01-07 | 2020-07-14 | 中国科学院上海微***与信息技术研究所 | Magnetic field sensor structure and preparation method thereof |
| WO2021253600A1 (en) * | 2020-06-15 | 2021-12-23 | 北京航空航天大学 | Magnetic sensor of monolithic integrated three-axis tunnel magnetoresistance and preparation method therefor |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20090115405A1 (en) * | 2007-11-01 | 2009-05-07 | Magic Technologies, Inc. | Magnetic field angular sensor with a full angle detection |
| US9279865B2 (en) * | 2012-05-09 | 2016-03-08 | Everspin Technologies, Inc. | Method and structure for testing and calibrating three axis magnetic field sensing devices |
-
2022
- 2022-12-22 CN CN202211656591.9A patent/CN115825826B/en active Active
Patent Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006010579A (en) * | 2004-06-28 | 2006-01-12 | Yamaha Corp | Magnetic sensor |
| CN102426344A (en) * | 2011-08-30 | 2012-04-25 | 江苏多维科技有限公司 | Triaxial magnetic field sensor |
| CN103913709A (en) * | 2014-03-28 | 2014-07-09 | 江苏多维科技有限公司 | Single-chip three-axis magnetic field sensor and manufacturing method thereof |
| CN104280700A (en) * | 2014-09-28 | 2015-01-14 | 江苏多维科技有限公司 | Single chip difference free layer push-pull type magnetic field sensor electric bridge and preparation method thereof |
| CN104776794A (en) * | 2015-04-16 | 2015-07-15 | 江苏多维科技有限公司 | Separately-encapsulated high-intensity magnetic-field magneto-resistance angle sensor |
| CN105093139A (en) * | 2015-06-09 | 2015-11-25 | 江苏多维科技有限公司 | Push-pull X shaft magneto-resistor sensor |
| CN105044631A (en) * | 2015-08-28 | 2015-11-11 | 江苏多维科技有限公司 | Half turning-over dual axle magneto resistance sensor |
| CN206671519U (en) * | 2017-03-24 | 2017-11-24 | 江苏多维科技有限公司 | A kind of single-chip twin shaft magneto-resistor linear transducer |
| CN108413992A (en) * | 2018-01-30 | 2018-08-17 | 江苏多维科技有限公司 | A kind of three axis premodulated low noise magnetic resistance sensors |
| CN110794348A (en) * | 2018-08-03 | 2020-02-14 | 爱盛科技股份有限公司 | Magnetic field sensing device |
| CN111413653A (en) * | 2019-01-07 | 2020-07-14 | 中国科学院上海微***与信息技术研究所 | Magnetic field sensor structure and preparation method thereof |
| WO2021253600A1 (en) * | 2020-06-15 | 2021-12-23 | 北京航空航天大学 | Magnetic sensor of monolithic integrated three-axis tunnel magnetoresistance and preparation method therefor |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115825826A (en) | 2023-03-21 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US9465056B2 (en) | Current sensor with temperature-compensated magnetic tunnel junction bridge | |
| US10734443B2 (en) | Dual manetoresistance element with two directions of response to external magnetic fields | |
| EP2752675B1 (en) | Mtj three-axis magnetic field sensor and encapsulation method thereof | |
| US9702943B2 (en) | Single chip push-pull bridge-type magnetic field sensor | |
| TWI774189B (en) | Magnetoresistance element and spin valve | |
| JP6525335B2 (en) | Single chip bridge type magnetic field sensor | |
| CN102565727B (en) | For measuring the magnetic resistance sensor in magnetic field | |
| EP2696209B1 (en) | Single-chip push-pull bridge-type magnetic field sensor | |
| US9606144B2 (en) | Probe card and method for testing magnetic sensors | |
| JP6474822B2 (en) | High sensitivity push-pull bridge magnetic sensor | |
| EP3062119B1 (en) | Push-pull bridge-type magnetic sensor for high-intensity magnetic fields | |
| EP2696211A1 (en) | Single chip bridge magnetic field sensor and preparation method thereof | |
| US9810748B2 (en) | Tunneling magneto-resistor device for sensing a magnetic field | |
| EP3088908A1 (en) | Single chip reference bridge type magnetic sensor for high-intensity magnetic field | |
| WO2012097673A1 (en) | Independently packaged bridge type magnetic field sensor | |
| JP2020153771A (en) | Magnetic sensor | |
| CN210665858U (en) | Large-dynamic-range magnetic sensor assembly | |
| CN115825826B (en) | Three-axis full-bridge circuit transformation type linear magnetic field sensor | |
| CN203811787U (en) | Single-chip three-axis linear magnetic sensor | |
| CN115856731B (en) | Magnetic field sensor and voltage measurement method | |
| EP2801834B1 (en) | Current sensor |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |