Current Sensor

Abstract

The current sensor comprises a measured current input component, which is composed of a first current shunt copper bar (11), a second current shunt copper bar (21), and a differential copper bar (31) arranged in the same direction, and a signal output component, which is composed of a substrate (51) and a magnetic induction module (41) fixed on the substrate (51). The signal output component is electrically insulated from the current input component. The measured current flows through a cross section perpendicular to the first current shunt copper bar (11), the second current shunt copper bar (21), and the differential copper bar (31), generating a magnetic field at the position of the magnetic induction module (41). The magnetic induction module (41) comprises at least a first magnetic induction unit (411) and a second magnetic induction unit (421). Two magnetic induction units (411, 412) are located between the differential copper bar (31) and the first current shunt copper bar (11), which differentially sense the differential mode magnetic field generated by the current input components, and generate a differential voltage signal to form the output signal of the current sensor. Thus, the advantages of high accuracy, adjustable and large current measurement range of this current sensor are realized.

Description

[Technical Field]

[0001] FIELD OF THE INVENTION Embodiments of the present invention relate to the technical field of electrical measurements, and in particular to current sensors. [Background technology]

[0002] A current sensor is a type of current detection device that can convert the detected information of the measured current into an electrical signal or other form of signal that meets certain standard requirements. These signals can then be used to meet the needs of information transmission, processing, storage, display, recording, and control. At present, current sensors are widely used in home appliances, smart grids, electric vehicles, wind power generation, and other fields.

[0003] Current sensors include magnetic current sensors such as Hall current sensors, fluxgate current sensors, and magnetoresistive current sensors. While Hall current sensors are the most mature in terms of technology, they suffer from low sensitivity, poor temperature drift characteristics, and limited bandwidth in high-precision current measurement scenarios. Fluxgate current sensors offer good linearity, high detection accuracy, and excellent temperature drift performance, but they are large in size, have narrow bandwidth, require complex circuitry, and are cost-intensive for applications where size is not a high requirement. Magnetoresistive current sensors are a promising new type of current sensor, boasting small size, large signal amplitude, high sensitivity, low noise, and easy integration with semiconductor circuits. This simplifies the design of back-end signal processing circuits, reducing the overall size and cost of the current sensor.

[0004] However, existing magnetoresistive current sensors, especially miniature chip-level ones, offer high detection accuracy but a limited current measurement range. High-sensitivity magnetoresistive current sensors generally have a small saturation field, making them prone to magnetic saturation when measuring large currents. For example, Allegro's ACS70331 integrated GMR current sensor includes a bridge structure made of GMR, which can sense the magnetic field generated in the opposite direction by the current being measured through a single-layer U-shaped copper conduction path. This magnetic field is then directly used as the bridge's input signal, significantly limiting the current sensor's usable range and resulting in a measurement range of only 2.5 A. Chip-level Hall current sensors, such as Allegro's ACS710, CrossChip Microsystems' CC6920, and Melexis' MLX91221, which have low sensitivity but large saturation fields, have a current sensor measurement range of only a few tens of amperes when using a single-layer U-shaped copper conduction path. Even if the U-shaped copper conduction path is replaced with a rectangular copper busbar path, such as in the case of Allegro's ACS756, the measurement range of the current sensor does not exceed 200A. Summary of the Invention [Problem to be solved by the invention]

[0005] SUMMARY OF THE INVENTION Embodiments of the present invention provide a current sensor that solves the problem of small measurement range of existing current sensors that are highly accurate and small in size. [Means for solving the problem]

[0006] An embodiment of the present invention provides a current sensor, the current sensor comprising: a current input component to be measured, comprising a first current shunt copper bar, a second current shunt copper bar, and a differential copper bar arranged between the first current shunt copper bar and the second current shunt copper bar, wherein the first current shunt copper bar, the second current shunt copper bar, and the differential copper bar are arranged in the same direction; a signal output component electrically isolated from the current-to-be-measured input component, the signal output component comprising a magnetic induction module and a substrate, the magnetic induction module being fixed on the substrate; The current to be measured flows through a cross section perpendicular to the first current shunt copper bar, the second current shunt copper bar, and the differential copper bar, generating a magnetic field at the position of the magnetic induction module; The magnetic induction module includes at least a first magnetic induction unit and a second magnetic induction unit, which are located between the differential copper bar and the first current shunt copper bar, and which differentially sense the differential mode magnetic field generated by the current input component to be measured and generate a differential voltage signal to form the output signal of the current sensor.

[0007] An embodiment of the present invention provides a current sensor, the current sensor comprising: a current input component to be measured, comprising a first current shunt copper bar and a second current shunt copper bar connected in parallel; a signal output component electrically isolated from the current-to-be-measured input component, the signal output component comprising a magnetic induction module and a substrate, the magnetic induction module being fixed on the substrate; The current to be measured flows through a cross section perpendicular to the first current shunt copper bar and the second current shunt copper bar, generating a magnetic field at the position of the magnetic induction module; the magnetic induction module comprises at least a first magnetic induction unit and a second magnetic induction unit, the first magnetic induction unit is located between the first current shunt copper bar and the second current shunt copper bar, the first magnetic induction unit and the second magnetic induction unit are located on the same horizontal plane, the horizontal plane is parallel to a surface on which the substrate is located, and in a direction perpendicular to the surface on which the substrate is located, the overlapping area of ​​the vertical projections of the first current shunt copper bar and the second current shunt copper bar on the surface on which the substrate is located does not overlap with the second magnetic induction unit; The first magnetic induction unit and the second magnetic induction unit differentially sense the magnetic field generated by the current input component to be measured and generate a differential voltage signal to form the output signal of the current sensor.

[0008] The current sensor provided by the embodiment of the present invention is a novel current sensor that can control the common-mode magnetic field operating point and solve the problem of magnetoresistive sensing elements being easily saturated, thereby addressing the high precision limitations on the measurement current range of existing current sensors. Furthermore, the structure of the current sensor provided by the embodiment of the present invention is applicable to a small-volume current sensor chip, thereby realizing high precision and an adjustable current measurement range of the current sensor and allowing it to be applied to various different operating ranges. It achieves the advantages of a simple structure, strong resistance to external magnetic field interference, the ability to measure large DC and AC currents, input and output electrical isolation, good linearity, high precision, good stability, a small volume, and a wide range.

[0009] In order to more clearly show the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings necessary for use in the embodiments or the prior art are briefly introduced below. Of course, the accompanying drawings described below are some specific embodiments of the present invention, but it is clear to those skilled in the art that the basic concepts of the device structure, driving method and manufacturing method disclosed and indicated by the various embodiments of the present invention can be extended and expanded to other structures and drawings, all of which are within the scope of the claims of the present invention. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic diagram illustrating a current sensor according to an embodiment of the present invention. [Figure 2] FIG. 2 is a schematic diagram illustrating a simulation of the current sensor of FIG. 1. [Figure 3] 2 is a schematic diagram illustrating a differential half-bridge configuration of the current sensor of FIG. 1. [Figure 4] 2 is a schematic diagram illustrating another bridge structure of the current sensor of FIG. 1. [Figure 5] 1. FIG. 4 is a schematic diagram illustrating yet another bridge structure of the current sensor of FIG. [Figure 6] FIG. 2 is a schematic diagram illustrating another current sensor according to an embodiment of the present invention. [Figure 7] FIG. 7 is a schematic diagram showing a differential full-bridge structure of the current sensor of FIG. 6. [Figure 8] FIG. 10 is a schematic diagram illustrating yet another current sensor according to an embodiment of the present invention. [Figure 9] FIG. 10 is a schematic diagram illustrating yet another current sensor according to an embodiment of the present invention. [Figure 10] FIG. 10 is a schematic diagram illustrating yet another current sensor according to an embodiment of the present invention. [Figure 11] FIG. 10 is a schematic diagram illustrating yet another current sensor according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] In order to make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and fully described below through the implementation method in the embodiments of the present invention with reference to the accompanying drawings. Of course, the described embodiments are only a part of the embodiments of the present invention, and are not all. Based on the basic concepts disclosed and indicated by the embodiments of the present invention, all other embodiments obtained by those skilled in the art are within the protection scope of the present invention.

[0012] 1, this is a schematic diagram of a current sensor according to an embodiment of the present invention. As shown in FIG. 1, the current sensor according to an embodiment of the present invention comprises a first current shunt copper bar 11, a second current shunt copper bar 21, and a differential copper bar 31 arranged between the first current shunt copper bar 11 and the second current shunt copper bar 21, and the current sensor comprises a current input component to be measured, in which the first current shunt copper bar 11, the second current shunt copper bar 21, and the differential copper bar 31 are arranged in the same direction, and a signal output component that is electrically insulated from the current input component to be measured and includes a magnetic induction module 41 and a substrate 51, and the magnetic induction module 41 is fixed on the substrate 51. The current to be measured is measured through the first current shunt copper bar 11, the second current shunt copper bar 21, and the differential copper bar 31. The current flows through a cross section perpendicular to the first current shunt copper bar 11, the second current shunt copper bar 21, and the differential copper bar 31, generating a magnetic field at the position of the magnetic induction module 41. The magnetic induction module 41 includes at least a first magnetic induction unit 411 and a second magnetic induction unit 421, which are located between the differential copper bar 31 and the first current shunt copper bar 11. The first magnetic induction unit 411 and the second magnetic induction unit 421 differentially sense the differential mode magnetic field generated by the current input component to be measured, and generate a differential voltage signal to form the output signal of the current sensor.

[0013] In this embodiment, the first current shunt copper bar 11, the second current shunt copper bar 21, and the differential copper bar 31 constitute a measured current input component. The three copper bars jointly shunt the measured current, and the current direction of the measured current in the first current shunt copper bar 11, the second current shunt copper bar 21, and the differential copper bar 31 are the same. As shown in FIG. 1, the first current shunt copper bar 11, the second current shunt copper bar 21, and the differential copper bar 31 are arranged in parallel along the Z direction.

[0014] The magnetic induction module 41 and the substrate 51 constitute a signal output component, which is electrically insulated from the current-to-be-measured input component. The magnetic induction module 41 is fixed on the substrate 51. As shown in FIG. 1 , the first current shunt copper bar 11 is disposed on the side of the magnetic induction module 41 far from the substrate 51, and the second current shunt copper bar 21 is disposed on the side of the substrate 51 far from the magnetic induction module 41. Along the direction shown in the drawing, the first current shunt copper bar 11 is disposed above the magnetic induction module 41, the second current shunt copper bar 21 is disposed below the differential copper bar 31, and the magnetic induction module 41 is disposed above the differential copper bar 31. The current to be measured flows through a cross section perpendicular to the first current shunt copper bar 11, the second current shunt copper bar 21, and the differential copper bar 31, generating a magnetic field at the position of the magnetic induction module 41. The cross sections of the first current shunt copper bar 11, the second current shunt copper bar 21, and the differential copper bar 31 are in the XZ plane, and therefore it can be understood that the current direction of the current to be measured is perpendicular to the XZ plane as shown in FIG.

[0015] The magnetic induction module 41 includes at least a first magnetic induction unit 411 and a second magnetic induction unit 421, which are located between the differential copper bar 31 and the first current shunt copper bar 11 and are arranged along the X direction. The first magnetic induction unit 411 and the second magnetic induction unit 421 differentially sense and measure the differential mode magnetic field generated by the current input component under test, and generate a differential voltage signal to form the output signal of the current sensor. Optionally, the sensitivity direction of the magnetic induction units is rightward, i.e., the X direction, as shown in FIG. 1 , so that the sensitivity direction of each magnetic induction unit of the magnetic induction module 41 is parallel to the plane on which the substrate 51 is located.

[0016] Optionally, the first magnetic induction unit 411 and the second magnetic induction unit 421 are arranged on the same horizontal plane, which is parallel to the surface on which the substrate 51 is located, and in a direction Z perpendicular to the surface on which the substrate 51 is located, the vertical projection of the differential copper bar 31 on the surface on which the substrate 51 is located covers the first magnetic induction unit 411 and does not overlap with the second magnetic induction unit 421, and in a direction Z perpendicular to the surface on which the substrate 51 is located, the vertical projection of the first current shunt copper bar 11 on the surface on which the substrate 51 is located covers the first magnetic induction unit 411 and the second magnetic induction unit 421, and the vertical projection of the second current shunt copper bar 21 on the surface on which the substrate 51 is located covers the first magnetic induction unit 411 and the second magnetic induction unit 421.

[0017] As described above, the first magnetic induction unit 411 and the second magnetic induction unit 421 are arranged on the same horizontal plane, which is parallel to the plane on which the substrate 51 is located, and which is perpendicular to the XZ plane. In the Z direction, vertical projections are made on the plane where the substrate 51 is located for the first current shunt copper bar 11, the second current shunt copper bar 21, the differential copper bar 31, the first magnetic induction unit 411, and the second magnetic induction unit 421. Therefore, the relationship between the projections of the structures on the plane where the substrate 51 is located is such that the projection of the first magnetic induction unit 411 is within the projection range of the differential copper bar 31, the projection of the second magnetic induction unit 421 is outside the projection range of the differential copper bar 31, the projection of the first current shunt copper bar 11 covers the projection of the first magnetic induction unit 411 and the projection of the second magnetic induction unit 421, and the projection of the second current shunt copper bar 21 covers the projection of the first magnetic induction unit 411 and the projection of the second magnetic induction unit 421. The magnetic field of each copper bar only needs to cover the range of the magnetic induction unit, thereby achieving a chip-level size of the current sensor.

[0018] Optionally, the current sensor further comprises a housing 61, and both the current input component to be measured and the signal output component are fixedly disposed inside the housing 61. Optionally, the differential copper bar 31 is disposed inside the substrate 51. In this embodiment, the housing 61 is a mechanical support housing, which serves to encase, fix, support, and provide an external interface for the various components of the current sensor. The differential copper bar 31 embedded inside the substrate 51, and its position within the substrate 51, is relatively close to the first magnetic induction unit 411.

[0019] Optionally, the sensitivity direction of the first magnetic induction unit 411 and the sensitivity direction of the second magnetic induction unit 421 are the same as or opposite to the direction of the magnetic field generated by the current to be measured through the differential copper bar 31 at the position of the first magnetic induction unit 411. When the current to be measured flows through the differential copper bar 31, the differential copper bar 31 generates a magnetic field at the position of the first magnetic induction unit 411, and the direction of the magnetic field is considered to be the same as the sensitivity direction of the first magnetic induction unit 411 and the sensitivity direction of the second magnetic induction unit 421. Specifically, referring to FIG. 1 , the direction of the magnetic field generated by the differential copper bar 31 at the position of the first magnetic induction unit 411 is in the plane where the magnetic induction module 41 is located and is perpendicular to the direction of the current to be measured. Here, the direction of the current to be measured is perpendicular to the XZ plane, so the direction of the magnetic field generated by the differential copper bar 31 at the position of the first magnetic induction unit 411 is parallel to the X direction.

[0020] Based on the above structure, the working principle of the current sensor will be described in detail through a concrete example.

[0021] Referring to Figure 2, this figure is a schematic diagram of a simulation of the current sensor of Figure 1. The measured current I inThe current is set to 50 A, and the cross-sectional width of the current input component to be measured is set to 10 mm. Combining with Figure 1, the cross-sectional width of the current input component to be measured is the size in the Z direction from the top surface of the first current shunt copper bar 11 to the bottom surface of the second current shunt copper bar 21, and the magnetic induction module 41 is disposed at a horizontal position 0.6 mm above the differential copper bar 31. Therefore, when the current to be measured flows through the copper bar in a direction perpendicular to the XZ plane of the cross section of the current input component to be measured, a magnetic field is generated at a horizontal position 0.6 mm above the differential copper bar 31.

[0022] As can be seen from the figure, there is an obvious difference between the magnetic fields at the edges of the vertical projection above the differential copper bar 31, i.e., near the positions of the first magnetic induction unit 411 and the second magnetic induction unit 421, and the magnetic field generated near the ±3 mm position on the X axis shown in Figure 2 is relatively uniform, which can effectively generate a differential mode magnetic field.

[0023] The first magnetic induction unit 411 is arranged in a magnetic field uniform region within the coverage of the vertical projection above the differential copper bar 31, and the second magnetic induction unit 421 is arranged in a magnetic field uniform region outside the coverage of the vertical projection above the differential copper bar 31, and these two magnetic induction units are simultaneously located in the magnetic field uniform region of the first current shunt copper bar 11, and the two magnetic induction units may also be simultaneously located in the magnetic field uniform region of the second current shunt copper bar 21, and the first current shunt copper bar 11, the second current shunt copper bar 21, and the differential copper bar 31 are connected in parallel to generate the measured current I in Next, if the material is homogeneous, the current density in the cross section of Figure 1 may be considered to be the same, i.e., the current is directly proportional to the cross-sectional area.

[0024] If the current flowing through the first current shunt copper bar 11 is I1, the current flowing through the second current shunt copper bar 21 is I2, and the current flowing through the differential copper bar 31 is I3, the following equation (1) holds: I in=I1+I2+I3(1)

[0025] Since the first magnetic induction unit 411 and the second magnetic induction unit 421 are both located within the magnetic field uniform region of the first current shunt copper bar 11 and the second current shunt copper bar 21, the current flowing through the first current shunt copper bar 11 generates a uniform magnetic field at the position of the first magnetic induction unit 411 and the second magnetic induction unit 421, and the current flowing through the second current shunt copper bar 21 generates a uniform magnetic field at the position of the first magnetic induction unit 411 and the second magnetic induction unit 421.

[0026] The linear constant of the magnetic field generated by the first current shunt copper bar 11 at the position of the first magnetic induction unit 411 and the second magnetic induction unit 421 is k1, the linear constant of the magnetic field generated by the second current shunt copper bar 21 at the position of the first magnetic induction unit 411 and the second magnetic induction unit 421 is k2, and the linear constant of the magnetic field generated by the differential copper bar 31 at the position of the first magnetic induction unit 411 is k 31 and the linear constant of the magnetic field generated by the differential copper bar 31 at the position of the second magnetic induction unit 421 is k 32 The right direction shown in the drawing is the positive direction of the magnetic field, and according to the Biot-Savart law that a current-carrying wire generates a magnetic field, the magnetic field H generated at the position of the first magnetic induction unit 411 by the current input component to be measured is 41 and the magnetic field H generated at the position of the second magnetic induction unit 421. 42 and change linearly with the current, and the following equation (2) is obtained. H 41 =-k1I1+k2I2+k 31 I3; H 42 =-k1I1+k2I2+k 32 I3(2)

[0027] An equivalent transformation is performed on equation (2), whereby the magnetic field at the location of the first magnetic induction unit 411 and the magnetic field at the location of the second magnetic induction unit 421 due to the current input component to be measured are converted into the common-mode magnetic field H, as shown by the following equation (3): CM and the differential mode magnetic field H DM It may be decomposed into

number

[0028] Correspondingly, the magnetic field of the current input component to be measured at the positions of the first magnetic induction unit 411 and the second magnetic induction unit 421 is expressed as the common-mode magnetic field H, which is expressed by the following equation (4): CM and the differential mode magnetic field H DM can be transformed into a superposition of H 41 =H CM +H DM ; H 42 =H CM -H DM (4)

[0029] The magnetic field generated by the differential copper bar 31 at the position of the second magnetic induction unit 421 is very small, so k 32 = 0, and thus equation (3) can be simplified to the following equation (5).

number

[0030] 1, the direction of the magnetic field generated by the first current shunt copper bar 11 at the location of the first magnetic induction unit 411 and the second magnetic induction unit 421 is opposite to the direction of the magnetic field generated by the second current shunt copper bar 21 at the location of the first magnetic induction unit 411 and the second magnetic induction unit 421, and therefore the two can be offset and reduced from each other. In addition, the common-mode magnetic field H of the current input component under test at the location of the first magnetic induction unit 411 and the second magnetic induction unit 421 CM is related to the first current shunt copper bar 11, the second current shunt copper bar 21, and the differential copper bar 31, and is the differential mode magnetic field H of the current input component to be measured at the positions of the first magnetic induction unit 411 and the second magnetic induction unit 421. DM is related only to the differential copper bar 31, and therefore the first current shunt copper bar 11 and the second current shunt copper bar 21 are connected to the differential mode magnetic field H at the positions of the first magnetic induction unit 411 and the second magnetic induction unit 421. DM without generating a common-mode magnetic field H CM Therefore, the current input range of the current sensor can be adjusted and increased.

[0031] Furthermore, in an ideal situation, the common-mode magnetic field H generated by the current input components to be measured at the locations of the first magnetic induction unit 411 and the second magnetic induction unit 421 is CM is completely offset to zero, so that the decomposition of the magnetic field generated by the measured current input component at the location of the first magnetic induction unit 411 and the second magnetic induction unit 421 results in the differential mode magnetic field H DM In combination with FIG. 1, the magnetic field generated by the differential copper bar 31 at the position of the second magnetic induction unit 421 is very small, and k 32 = 0, and thus equation (3) can be simplified to the following equation (6). H CM=0; H DM =k 31 I3 / 2 (6)

[0032] Next, equation (4) can be simplified to the following equation (7): H 41 =H DM =k 31 I3 / 2; H 42 =-H DM =-k 31 I3 / 2 (7)

[0033] Generally, the first current shunt copper bar 11, the second current shunt copper bar 21, and the differential copper bar 31 jointly form a current to be measured I in The magnetic field at the positions of the first magnetic induction unit 411 and the second magnetic induction unit 421 is shunted, and the measured current I in is directly proportional to the differential mode magnetic field H DM The detection of the measured current can be achieved by measuring

[0034] As can be seen by combining equations (6) and (7), in an ideal situation, the common-mode magnetic field H generated by the current input components to be measured at the locations of the first magnetic induction unit 411 and the second magnetic induction unit 421 is CM can be completely offset, and therefore the operating range of the magnetoresistive sensing element is DM , which provides the maximum measurement current range of the current sensor.

[0035] In an embodiment of the present invention, a first current shunt copper bar, a second current shunt copper bar, and a differential copper bar constitute a current input component to be measured, generating a magnetic field at the location of the magnetic induction module. The two magnetic induction units of the magnetic induction module differentially sense the differential-mode magnetic field generated when the current to be measured flows through the current input component to generate a differential voltage signal, which is output by the magnetic induction module to form the output signal of the current sensor. The current sensor provided by the embodiment of the present invention is a novel current sensor that can control the common-mode magnetic field operating point and solve the problem of magnetoresistive sensing elements being easily saturated, thereby addressing the high accuracy limitations on the measurement current range of existing current sensors. Furthermore, the structure of the current sensor provided by the embodiment of the present invention is applicable to a small-volume current sensor chip, thereby achieving high accuracy and an adjustable current measurement range of the current sensor and allowing it to be adapted to various different operating ranges. It achieves the advantages of a simple structure, strong resistance to external magnetic field interference, the ability to measure large DC and AC currents, input and output electrical isolation, good linearity, high accuracy, good stability, a small volume, and a wide range.

[0036] Optionally, the first magnetic induction unit comprises at least one magnetoresistive bridge arm, the second magnetic induction unit comprises at least one magnetoresistive bridge arm, the magnetoresistive bridge arms of the first magnetic induction unit and the magnetoresistive bridge arms of the second magnetic induction unit are electrically connected to form a differential half-bridge structure or a differential full-bridge structure, all the magnetoresistive bridge arms have the same sensitivity direction, and the magnetoresistive bridge arms are formed by connecting at least one magnetoresistive sensing element in series and parallel. Optionally, the magnetic induction unit comprises any one of anisotropic magnetoresistors (AMR), giant magnetoresistors (GMR), tunneling magnetoresistors (TMR), and colossal magnetoresistors (CMR).

[0037] Referring to FIG. 3, this figure is a schematic diagram of the differential half-bridge structure of the current sensor of FIG. 1. As shown in FIG. 3, the first magnetic induction unit 411 includes one magnetoresistive bridge arm 411a, and the second magnetic induction unit 421 includes one magnetoresistive bridge arm 421a. Each magnetoresistive bridge arm is formed by connecting one or more magnetoresistive sensing elements in series and parallel, and the two magnetoresistive bridge arms 411a and 421a have the same sensitivity direction, for example, the sensitivity direction is the horizontal rightward X direction shown in FIG. 1, electrically forming a differential half-bridge structure. Optionally, the magnetoresistive sensing elements constituting the magnetic induction units of FIG. 3 are tunnel magnetoresistors (TMRs).

[0038] As can be seen from the above analysis and a combination of Figures 1 and 3, the first current shunt copper bar 11 and the second current shunt copper bar 21 are effective in suppressing the differential mode magnetic field H DM without generating a common-mode magnetic field H CM can only be offset and reduced, the offset common-mode magnetic field H CM may be in the same direction, nulled, or in opposite directions.

[0039] Offset common-mode magnetic field H CM Assuming that the directions are the same, the differential mode magnetic field H DM Therefore, the rightward magnetic field at the position of the first magnetic induction unit 411 is greater than the rightward magnetic field at the position of the second magnetic induction unit 421. Since the two magnetoresistive bridge arms 411a and 421a both have rightward sensitive directions, the rightward magnetic field at the position of the magnetoresistive bridge arm 411a is greater than the rightward magnetic field at the position of the magnetoresistive bridge arm 421a. Therefore, by setting the resistance of the magnetoresistive bridge arm 411a smaller than the resistance of the magnetoresistive bridge arm 421a, the magnetic field can be converted into a voltage. Therefore, Va in FIG. 3 changes correspondingly according to the situation of the current to be measured, forming a differential voltage signal.

[0040] 1 , optionally, the current sensor further includes an open-loop signal conditioning circuit 431, which performs conditioning and amplification, temperature compensation, and linearity correction on the differential voltage signal. In this embodiment, the magnetic induction module 41 further includes an open-loop signal conditioning circuit 431, which performs conditioning and amplification, temperature compensation, and linearity correction on the differential voltage signal generated by the first magnetic induction unit 411 and the second magnetic induction unit 421, thereby forming an output signal of the magnetic induction module 41. Therefore, the output of the magnetic induction module 41 forms the output signal of the current sensor.

[0041] As described above, the differential copper bar 31 forms a differential mode magnetic field, and the common mode magnetic field formed by the first current shunt copper bar 11 and the second current shunt copper bar 21 offsets and reduces the common mode magnetic field formed by the differential copper bar 31, thereby extending the measurement current range of the current sensor.

[0042] In this embodiment, an open-loop signal conditioning circuit is employed to create a novel differential current sensor with an adjustable current measurement range, effectively increasing the measurement range of the current being measured. This effectively solves the problem of magnetoresistive sensing elements being prone to saturation, provides strong resistance to external magnetic field interference, and features characteristics including the ability to measure large DC and AC currents, a simple structure, and input and output electrical isolation. Here, the copper bar magnetic field only needs to cover the range of the magnetic induction unit, allowing the current sensor to achieve a chip-level volume. Combined with the characteristics of tunneling magnetoresistive devices, including small volume, high signal amplification, high sensitivity, low noise, and ease of integration with semiconductor circuits, this further simplifies the design of the current sensor's back-end signal processing circuit, reducing the overall volume and cost of the current sensor.

[0043] Optionally, the first magnetic induction unit comprises a first half bridge or a first full bridge, and the second magnetic induction unit comprises a second half bridge or a second full bridge, and an output voltage difference between the bridge of the first magnetic induction unit and the bridge of the second magnetic induction unit generates a differential voltage signal.

[0044] Optionally, the first half bridge comprises two magnetoresistive bridge arms with opposite sensitivity directions, the second half bridge comprises two magnetoresistive bridge arms with opposite sensitivity directions, or the first full bridge comprises four magnetoresistive bridge arms with two electrically connected adjacent magnetoresistive bridge arms having opposite sensitivity directions, and the second full bridge comprises four magnetoresistive bridge arms with two electrically connected adjacent magnetoresistive bridge arms having opposite sensitivity directions, wherein the magnetoresistive bridge arms are formed by one magnetoresistive sensing element or by connecting two or more magnetoresistive sensing elements in series and parallel.

[0045] Referring to Figure 4, this figure is a schematic diagram of another bridge structure of the current sensor of Figure 1. As shown in Figure 4, the first magnetic induction unit 411 includes a first half bridge, and the second magnetic induction unit 421 includes a second half bridge. The first half bridge includes two magnetoresistive bridge arms 411b1 and 411b2, and the second half bridge includes two magnetoresistive bridge arms 421b1 and 421b2.

[0046] The sensitivity directions of the magnetoresistive bridge arms in each bridge are different: in the first half bridge, the sensitivity directions of magnetoresistive bridge arms 411b1 and 411b2 are opposite, specifically, the sensitivity direction of magnetoresistive bridge arm 411b1 is to the left as shown in the figure, and the sensitivity direction of magnetoresistive bridge arm 411b2 is to the right as shown in the figure; in the second half bridge, the sensitivity directions of magnetoresistive bridge arms 421b1 and 421b2 are opposite, specifically, the sensitivity direction of magnetoresistive bridge arm 421b1 is to the left as shown in the figure, and the sensitivity direction of magnetoresistive bridge arm 421b2 is to the right as shown in the figure.

[0047] As can be seen from the above analysis and a combination of Figures 1 and 4, the first current shunt copper bar 11 and the second current shunt copper bar 21 are effective in suppressing the differential mode magnetic field H DM without generating a common-mode magnetic field H CM can only be offset and reduced, the offset common-mode magnetic field H CM may be in the same direction, nulled, or in opposite directions.

[0048] Assuming that the offset common-mode magnetic field is rightward and that the rightward magnetic field at the position of the first magnetic induction unit 411 after the differential-mode magnetic field is superimposed is greater than the rightward magnetic field at the position of the second magnetic induction unit 421, the resistance of the magnetoresistive bridge arm 411b1 is greater than the resistance of the magnetoresistive bridge arm 411b2, the resistance of the magnetoresistive bridge arm 421b1 is greater than the resistance of the magnetoresistive bridge arm 421b2, and the resistance difference between the magnetoresistive bridge arms 411b1 and 411b2 is greater than the resistance difference between the magnetoresistive bridge arms 421b1 and 421b2, thereby realizing magnetic field-to-voltage conversion. Therefore, in Figure 4, the output voltage V1b of the bridge of the first magnetic induction unit 411 and the output voltage V2b of the bridge of the second magnetic induction unit 421 change correspondingly according to the current to be measured, and the difference between the two output voltages forms a differential voltage signal.

[0049] 5, which is a schematic diagram of yet another bridge structure of the current sensor of FIG. 1. As shown in FIG. 5, the first magnetic induction unit 411 includes a first full bridge, and the second magnetic induction unit 421 includes a second full bridge. The first full bridge includes four magnetoresistive bridge arms 411c1, 411c2, 411c3, and 411c4, and the second full bridge includes four magnetoresistive bridge arms 421c1, 421c2, 421c3, and 421c4. The sensitive directions of the magnetoresistive bridge arms in each bridge do not need to be exactly the same.

[0050] In the first full bridge, each of magnetoresistive bridge arms 411c1, 411c2, 411c3, and 411c4 in the full-bridge connection structure has a sensitivity direction opposite to that of its electrically adjacent magnetoresistive bridge arm. That is, magnetoresistive bridge arm 411c1 has a sensitivity direction opposite to that of its adjacent magnetoresistive bridge arms 411c2 and 411c3, and magnetoresistive bridge arm 411c4 has a sensitivity direction opposite to that of its adjacent magnetoresistive bridge arms 411c2 and 411c3. As a result, the sensitivity directions of magnetoresistive bridge arms 411c1 and 411c4 are the same, pointing to the right, as shown in the figure, while the sensitivity directions of magnetoresistive bridge arms 411c2 and 411c3 are the same, pointing to the left, as shown in the figure, and the sensitivity directions of magnetoresistive bridge arms 411c1 and 411c2 are opposite.

[0051] In the second full bridge, each of magnetoresistive bridge arms 421c1, 421c2, 421c3, and 421c4 in the full-bridge connection structure has a sensitivity direction opposite to that of its electrically adjacent magnetoresistive bridge arm. That is, magnetoresistive bridge arm 421c1 has a sensitivity direction opposite to that of adjacent magnetoresistive bridge arms 421c2 and 421c3, and magnetoresistive bridge arm 421c4 has a sensitivity direction opposite to that of adjacent magnetoresistive bridge arms 421c2 and 421c3. As a result, the sensitivity directions of magnetoresistive bridge arms 421c1 and 421c4 are the same, pointing to the right, as shown in the figure, while the sensitivity directions of magnetoresistive bridge arms 421c2 and 421c3 are the same, pointing to the left, as shown in the figure, and the sensitivity directions of magnetoresistive bridge arms 421c1 and 421c2 are opposite.

[0052] As can be seen from the above analysis and a combination of Figures 1 and 5, the first current shunt copper bar 11 and the second current shunt copper bar 21 are effective in suppressing the differential mode magnetic field H DM without generating a common-mode magnetic field H CMcan only be offset and reduced, the offset common-mode magnetic field H CM may be in the same direction, nulled, or in opposite directions.

[0053] Assuming that the offset common-mode magnetic field is rightward, and the rightward magnetic field at the position of first magnetic induction unit 411 after the differential-mode magnetic field is superimposed is greater than the rightward magnetic field at the position of second magnetic induction unit 421, the resistance of magnetoresistive bridge arms 411c2 and 411c3 is greater than the resistance of magnetoresistive bridge arms 411c1 and 411c4, the resistance of magnetoresistive bridge arms 421c2 and 421c3 is greater than the resistance of magnetoresistive bridge arms 421c2 and 421c3, the difference between the resistance of magnetoresistive bridge arms 411c2 and 411c3 and the resistance of magnetoresistive bridge arms 411c1 and 411c4 is difference 1, and the difference between the resistance of magnetoresistive bridge arms 421c2 and 421c3 and the resistance of magnetoresistive bridge arms 421c1 and 421c4 is difference 2, where difference 1 is greater than difference 2. As a result, the magnetic field is converted into a voltage. Here, in Figure 5, the voltage difference between V1c1 and V1c2 forms the output voltage of the bridge of the first magnetic induction unit 411, and the voltage difference between V2c1 and V2c2 forms the output voltage of the bridge of the second magnetic induction unit 421. The output voltages of the first magnetic induction unit 411 and the second magnetic induction unit 421 change correspondingly according to the situation of the current to be measured, and the difference between the two output voltages forms a differential voltage signal.

[0054] The above-mentioned magnetoresistive bridge arm may consist of one magnetoresistive sensing element, or the above-mentioned magnetoresistive bridge arm may consist of multiple magnetoresistive sensing elements connected in series and parallel.

[0055] For example, based on any of the above-mentioned embodiments, in accordance with the characteristics of the closed-loop magnetic field current sensor, including high linearity, good temperature characteristics, high stability and reliability, and high-precision current measurement, a closed-loop magnetic field feedback coil is integrated into the current sensor to achieve high-precision current measurement. A specific example is provided below.

[0056] Optionally, the first magnetic induction unit comprises at least one magnetoresistive bridge arm, the second magnetic induction unit comprises at least one magnetoresistive bridge arm, the magnetoresistive bridge arms of the first magnetic induction unit and the magnetoresistive bridge arms of the second magnetic induction unit are electrically connected to form a differential half-bridge structure or a differential full-bridge structure, all the magnetoresistive bridge arms have the same sensitivity direction, and the magnetoresistive bridge arms are formed by connecting at least one magnetoresistive sensing element in series and parallel. Optionally, the magnetic induction unit comprises any one of anisotropic magnetoresistors (AMR), giant magnetoresistors (GMR), tunneling magnetoresistors (TMR), and colossal magnetoresistors (CMR).

[0057] Optionally, the current sensor further includes a closed-loop signal conditioning circuit and a magnetic field feedback coil, wherein the closed-loop signal conditioning circuit, the magnetic field feedback coil, the first magnetic induction unit, and the second magnetic induction unit constitute a closed-loop magnetic field feedback component, and after being amplified by the closed-loop signal conditioning circuit, the differential voltage signal passes through the magnetic field feedback coil to generate a feedback magnetic field to offset the differential mode magnetic field in opposite directions, and when dynamic equilibrium of the magnetic field is reached, the first magnetic induction unit and the second magnetic induction unit operate at an equal common mode magnetic field operating point, and then the feedback current of the magnetic field feedback coil is sampled to form an output signal of the magnetic induction module.

[0058] Referring to FIG. 6, this figure is a schematic diagram of another current sensor according to an embodiment of the present invention. Referring to FIG. 7, this figure is a schematic diagram of a differential full-bridge structure of the current sensor of FIG. 6. As shown in FIG. 6, the current sensor further includes a closed-loop signal conditioning circuit 441 and a magnetic field feedback coil 451. As shown in FIG. 7, the first magnetic induction unit 411 includes two magnetoresistive bridge arms 411d1 and 411d2, and the second full-bridge 421 includes two magnetoresistive bridge arms 421d1 and 421d2. Each magnetoresistive bridge arm is configured with one or more magnetoresistive sensing elements connected in series and parallel. The sensitivity directions of the four magnetoresistive bridge arms 411d1, 411d2, 421d1, and 421d2 are the same, for example, the sensitivity direction is horizontally rightward as shown in FIG. 6, electrically forming a differential full-bridge structure. Optionally, the magnetoresistive sensing element that makes up the magnetic induction unit of FIG. 7 is a tunneling magnetoresistor TMR.

[0059] Referring to FIG. 6, the first current shunt copper bar 11, the second current shunt copper bar 21, and the differential copper bar 31 are connected in parallel to shunt the current to be measured. The differential copper bar 31 forms a differential mode magnetic field. The common mode magnetic field formed by the first current shunt copper bar 11, the second current shunt copper bar 21, and the common mode magnetic field formed by the differential copper bar 31 offset and reduce each other. The difference from the differential current sensor shown in FIG. 1 is that the current sensor shown in FIG. 6 employs a differential full-bridge circuit, a closed-loop signal conditioning circuit 441, and a magnetic field feedback coil 451 shown in FIG. 7 to form a closed-loop magnetic field negative feedback, thereby forming a closed-loop magnetic field current sensor. The closed-loop magnetic field current sensor has characteristics such as high linearity, good temperature characteristics, high stability and reliability, and high-precision current measurement.

[0060] As can be seen by combining the above analysis and FIGS. 6 and 7, the offset common-mode magnetic field H of the current input component to be measured at the locations of the first magnetic induction unit 411 and the second magnetic induction unit 421 CM are in the same direction, and the differential mode magnetic field H DM Therefore, the rightward magnetic field at the position of the first magnetic induction unit 411 is greater than the rightward magnetic field at the position of the second magnetic induction unit 421. The sensitivity directions of the four magnetoresistive bridge arms 411d1, 411d2, 421d1, and 421d2 are all rightward, and the rightward magnetic field at the positions of the magnetoresistive bridge arms 411d1 and 411d2 is greater than the rightward magnetic field at the positions of the magnetoresistive bridge arms 421d1 and 421d2. Therefore, the resistance of the magnetoresistive bridge arms 411d1 and 411d2 is smaller than the resistance of the magnetoresistive bridge arms 421d1 and 421d2. As a result, in FIG. 7, the Vd2 voltage is greater than the Vd1 voltage, and a differential voltage signal is formed.

[0061] As described above, the closed-loop signal conditioning circuit 441, the magnetic field feedback coil 451, the first magnetic induction unit 411, and the second magnetic induction unit 421 constitute a closed-loop magnetic field feedback. The closed-loop signal conditioning circuit 441 performs conditioning, amplification, temperature compensation, and linearity correction on the differential voltage signals of the first magnetic induction unit 411 and the second magnetic induction unit 421. The amplified differential voltage signal passes through the magnetic field feedback coil 451 to generate a feedback magnetic field that offsets the differential mode magnetic field in the opposite direction. When dynamic balance of the magnetic fields is achieved, the first magnetic induction unit 411 and the second magnetic induction unit 421 operate at an equal common mode magnetic field operating point. The feedback current of the magnetic field feedback coil 451 is then sampled via a sampling resistor to form the output signal of the magnetic induction module 41.

[0062] Optionally, the magnetic field feedback coil 451 is integrated and disposed inside the magnetic induction module 41 , or the magnetic field feedback coil 451 is integrated and disposed inside the substrate 51 .

[0063] 6, the magnetic field feedback coil 451, the first magnetic induction unit 411, and the second magnetic induction unit 421 are all disposed inside the magnetic induction module 41. The magnetic field feedback coil 451 is not integrated with the magnetic induction unit, and the two are disposed so as to be separated from each other.

[0064] 8, which is a schematic diagram of yet another current sensor according to an embodiment of the present invention. As shown in FIG. 8, a magnetic field feedback coil 451 is integrated and disposed inside the magnetic induction module 41, specifically, the magnetic field feedback coil 451 is integrated and disposed inside the first magnetic induction unit 411, and the magnetic field feedback coil 451 is also integrated and disposed inside the second magnetic induction unit 421.

[0065] 9, which is a schematic diagram of yet another current sensor according to an embodiment of the present invention. As shown in FIG. 9, a magnetic field feedback coil 451 is integrated and disposed inside a substrate 51.

[0066] Note that the plane on which the magnetic field feedback coil 451 is located is parallel to the plane on which the substrate 51 is located, i.e., the plane on which the magnetic field feedback coil 451 is located is parallel to the plane on which the first magnetic induction unit 411 and the second magnetic induction unit 421 are located. The magnetic field feedback coil 451 is cross-sectioned along the XZ plane, with the cross-section centerline parallel to the Z direction. The two sides of the cross-section centerline are symmetrically distributed, with the current direction on one side of the cross-section centerline perpendicular to the XZ plane and opposite to the direction of the measured current in the copper bar, and the current direction on the other side of the cross-section centerline perpendicular to the XZ plane and the same direction as the measured current in the copper bar. Taking FIG. 6 as an example, optionally, the current direction on the left side of the cross-section centerline is outward, perpendicular to the paper plane, and the current direction on the right side of the cross-section centerline is inward, perpendicular to the paper plane, with the measured current direction in the copper bar being inward, perpendicular to the paper plane.

[0067] Consider the above-described situation where the rightward magnetic field at the position of the first magnetic induction unit 411 is greater than the rightward magnetic field at the position of the second magnetic induction unit 421, with respect to the direction of the feedback magnetic field generated by the magnetic field feedback coil 451. To offset the differential mode magnetic field in the opposite direction, in the cross-sectional view of the current sensor shown in FIG. 6, the cross-sectional current direction of the conductor of the magnetic field feedback coil 451 arranged horizontally below the first magnetic induction unit 411 is outward, perpendicular to the plane of the paper, while the cross-sectional current direction of the conductor of the magnetic field feedback coil 451 arranged horizontally below the second magnetic induction unit 421 is inward, perpendicular to the plane of the paper. Therefore, the magnetic field feedback coil 451 generates a leftward feedback magnetic field at the position of the first magnetic induction unit 411, and the magnetic field feedback coil 451 generates a rightward feedback magnetic field at the position of the second magnetic induction unit 421, thereby offsetting the differential mode magnetic field in the opposite direction and achieving dynamic equilibrium of the magnetic field.

[0068] According to the current sensor provided by the embodiment of the present invention, the first and second current shunt copper bars implement current shunting with respect to the differential copper bar, and the magnetic fields generated by the first and second current shunt copper bars at the position of the magnetic induction module have opposite directions, allowing the magnetic fields to be partially or completely offset so that the current measurement range is adjustable, effectively increasing the range of the current to be measured, thereby solving the problem of the magnetoresistive sensing element being easily saturated and addressing the high precision limitations on the measurement current range of existing current sensors, and leading to the advantages of strong resistance to external magnetic field interference, low noise, good linearity, high accuracy, and good stability.

[0069] An embodiment of the present invention further provides a current sensor that differs from the current sensor described in any of the above-described embodiments. Specifically, the current sensor provided by this and subsequent embodiments does not include a differential copper bar.

[0070] 10, which is a schematic diagram of yet another current sensor according to an embodiment of the present invention. As shown in FIG. 10, the current sensor provided by this embodiment includes a current input component to be measured, which is composed of a first current shunt copper bar 12 and a second current shunt copper bar 22 connected in parallel, and a signal output component that is electrically insulated from the current input component to be measured and includes a magnetic induction module 42 and a substrate 52, and the magnetic induction module 42 is fixed on the substrate 52. The current to be measured flows through a cross section perpendicular to the first current shunt copper bar 12 and the second current shunt copper bar 22, generating a magnetic field at the position of the magnetic induction module 42. The magnetic induction module 42 includes at least a first magnetic induction unit 412 and a second magnetic induction unit 422. The magnetic induction unit 412 is located between the first current shunt copper bar 12 and the second current shunt copper bar 22, and the first magnetic induction unit 412 and the second magnetic induction unit 422 are located on the same horizontal plane, which is parallel to the plane on which the substrate 52 is located. In a direction Z perpendicular to the plane on which the substrate 52 is located, the overlapping areas of the vertical projections of the first current shunt copper bar 12 and the second current shunt copper bar 22 on the plane on which the substrate 52 is located do not overlap with the second magnetic induction unit 422. The first magnetic induction unit 412 and the second magnetic induction unit 422 differentially sense the magnetic field generated by the current input component to be measured and generate a differential voltage signal to form the output signal of the current sensor.

[0071] In this embodiment, the cross section of the first current shunt copper bar 12 and the second current shunt copper bar 22 is the XZ plane, and the current to be measured flows through the copper bars in a direction perpendicular to the XZ plane, generating a magnetic field. That is, the current direction of the current to be measured is perpendicular to the XZ plane, and the specific current direction is all perpendicular to the paper and inward.

[0072] The magnetic induction module 42 includes at least a first magnetic induction unit 412 and a second magnetic induction unit 422. The first magnetic induction unit 412 and the second magnetic induction unit 422 are located on the same horizontal plane, which is parallel to the surface on which the substrate 52 is located. Specifically, the first magnetic induction unit 412 and the second magnetic induction unit 422 are located above the substrate 52.

[0073] The first magnetic induction unit 412 is disposed between the first current shunt copper bar 12 and the second current shunt copper bar 22, i.e., in the Z direction, the overlapping range of the vertical projections of the first current shunt copper bar 12 and the second current shunt copper bar 22 covers the first magnetic induction unit 412, and in the Z direction, the overlapping range of the vertical projections of the first current shunt copper bar 12 and the second current shunt copper bar 22 does not overlap with the second magnetic induction unit 422, i.e., the second magnetic induction unit 422 is located outside the overlapping range of the vertical projections of the first current shunt copper bar 12 and the second current shunt copper bar 22.

[0074] The first magnetic induction unit 412 and the second magnetic induction unit 422 differentially sense the magnetic field generated when the current to be measured flows through the current to be measured input component and generate a differential voltage signal, and at this time, the differential voltage signal output by the magnetic induction module 42 forms the output signal of the current sensor.

[0075] Optionally, the current sensor further comprises a housing 62, and both the measured current input component and the signal output component are fixedly disposed within the housing 62, which is a mechanical support housing. It is noted that the housing 62 further supports a second magnetic induction unit 422, and the magnetic induction module 42 employs an open-loop signal conditioning circuit 432.

[0076] Optionally, the sensitivity direction of the first magnetic induction unit 412 and the sensitivity direction of the second magnetic induction unit 422 are the same. As shown in FIG. 10 , the sensitivity direction of the magnetic induction units is the right-facing X direction. The first current shunt copper bar 12 generates a left-facing magnetic field at the position of the first magnetic induction unit 412, and the second current shunt copper bar 22 generates a right-facing magnetic field at the position of the first magnetic induction unit 412, and the two can offset and reduce each other. The magnetic field generated by the current input component to be measured at the position of the second magnetic induction unit 422 is determined by the relative position between the second magnetic induction unit 422 and the current input component to be measured. Due to the structure of the current sensor shown in FIG. 10 , the magnetic field generated by the current input component to be measured at the position of the second magnetic induction unit 422 may be approximated as zero magnetic field.

[0077] In this embodiment, the first and second current shunt copper bars 12 and 22 shunt the current to be measured, generating opposing magnetic fields in the first magnetic induction unit 412. The two can offset and reduce each other. By adjusting the position and structure of the current-to-be-measured input components, the first and second current shunt copper bars 12 and 22 can generate a zero magnetic field in the second magnetic induction unit 422. This effectively solves the problem of magnetoresistive sensing elements becoming saturated during large current measurements, achieving the effect of adjusting the current measurement range. This current sensor also boasts simple structure, small volume, electrical isolation between input and output, the ability to measure large DC and AC currents, an adjustable measurement range, and low cost.

[0078] The present embodiment further provides a current sensor different from the current sensor described in any of the above-described embodiments, specifically, the current sensor provided by this embodiment employs only one copper bar for the current shunt.

[0079] 11, this figure is a schematic diagram of yet another current sensor according to an embodiment of the present invention. As shown in FIG. 11, the current sensor provided by this embodiment includes a current input component to be measured, which is composed of a current shunt copper bar 13 and a differential copper bar 33 arranged in the same direction, and a signal output component that is electrically insulated from the current input component to be measured and includes a magnetic induction module 43 and a substrate 53, and the magnetic induction module 43 is fixed on the substrate 53. The current to be measured flows through a cross section perpendicular to the current shunt copper bar 13 and the differential copper bar 33, generating a magnetic field at the position of the magnetic induction module 43. The magnetic induction module 43 includes at least a first magnetic induction unit 413 and a second magnetic induction unit 423, and the first magnetic induction unit 413 and the second magnetic induction unit 423 are positioned on the same horizontal plane. The horizontal plane is parallel to the plane on which the substrate 53 is located, and the current shunt copper bar 13 is disposed below the differential copper bar 33 or above the magnetic induction module 43. In a direction perpendicular to the plane on which the substrate 53 is located, the vertical projection of the differential copper bar 33 on the plane on which the substrate 53 is located covers the first magnetic induction unit 413 and does not overlap with the second magnetic induction unit 423. The vertical projection of the current shunt copper bar 13 on the plane on which the substrate 53 is located covers the first magnetic induction unit 413 and the second magnetic induction unit 423. The first magnetic induction unit 413 and the second magnetic induction unit 423 differentially sense the magnetic field generated by the current input component to be measured and generate a differential voltage signal to form the output signal of the current sensor.

[0080] In this embodiment, the cross section of the current shunt copper bar 13 and the differential copper bar 33 is the XZ plane, and the current to be measured flows through the copper bars in a direction perpendicular to the XZ plane, generating a magnetic field. That is, the current direction of the current to be measured is perpendicular to the XZ plane, and the specific current direction is all perpendicular to the paper surface and inward.

[0081] The magnetic induction module 43 includes at least a first magnetic induction unit 413 and a second magnetic induction unit 423. The first magnetic induction unit 413 and the second magnetic induction unit 423 are located on the same horizontal plane, which is parallel to the plane on which the substrate 53 is located. Specifically, the first magnetic induction unit 413 and the second magnetic induction unit 423 are located above the substrate 53.

[0082] In this embodiment, the current shunt copper bar 13 is arranged below the differential copper bar 33, and the vertical projection of the current shunt copper bar 13 on the surface on which the substrate 53 is located covers the first magnetic induction unit 413 and the second magnetic induction unit 423 in the Z direction, and the differential copper bar 33 is arranged on one side closer to the first magnetic induction unit 413 inside the substrate 53, and its vertical projection covers the first magnetic induction unit 413 and does not overlap with the second magnetic induction unit 423.

[0083] The first magnetic induction unit 413 and the second magnetic induction unit 423 differentially sense the magnetic field generated when the current to be measured flows through the current to be measured input component, and generate a differential voltage signal, at which time the differential voltage signal output by the magnetic induction module 43 forms the output signal of the current sensor.

[0084] Optionally, the current sensor further includes a housing 63, in which both the current input component to be measured and the signal output component are fixedly disposed, and the housing 63 is a mechanical support housing. The magnetic induction module 43 employs an open-loop signal conditioning circuit 433. Optionally, the sensitivity direction of the first magnetic induction unit 413 is the same as that of the second magnetic induction unit 423, which is the rightward X direction as shown in FIG. 11 . By controlling the resistance and series / parallel connection relationship of the current shunt copper bar 13 and the differential copper bar 33, most of the current can be made to flow through the current shunt copper bar 13, thereby adjusting and extending the measurement range of the current sensor. In addition, a connection scheme in which the current shunt copper bar 13 and the differential copper bar 33 have opposite current directions can also be adopted to generate opposite magnetic fields of the magnetic induction module 43. In addition, the differential copper bar 33 may also be selected to be disposed above the magnetic induction module 43, in which case the current shunt copper bar 13 and the differential copper bar 33 can similarly generate opposite magnetic fields in the magnetic induction module 43.

[0085] This embodiment is a simplification of the above-mentioned embodiment, with a simpler structure, smaller volume, and further reduced cost. By adjusting the position and structure of the current input component to be measured, the measurement range of the current sensor can be adjusted and extended. It has the characteristics of electrical isolation of input and output, the ability to measure large DC and AC currents, an adjustable measurement range, and low cost.

[0086] It should be noted that the above description is merely a preferred embodiment of the present invention and the technical principles adopted. Those skilled in the art should understand that the present invention is not limited to the specific embodiments described herein, and that those skilled in the art can make various obvious modifications, rearrangements, mutual combinations, and substitutions without departing from the protective scope of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited merely to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is defined by the appended claims.

Claims

1. A current sensor, a current input component to be measured, comprising a first current shunt copper bar, a second current shunt copper bar, and a differential copper bar arranged between the first current shunt copper bar and the second current shunt copper bar, wherein the first current shunt copper bar, the second current shunt copper bar, and the differential copper bar are arranged in the same direction; a signal output component electrically isolated from the current input component to be measured, the signal output component comprising a magnetic induction module and a substrate, the magnetic induction module being fixed on the substrate; A current to be measured flows through a cross section perpendicular to the first current shunt copper bar, the second current shunt copper bar, and the differential copper bar, generating a magnetic field at the position of the magnetic induction module; the magnetic induction module comprises at least a first magnetic induction unit and a second magnetic induction unit, the first magnetic induction unit and the second magnetic induction unit are located between the differential copper bar and the first current shunt copper bar, the first magnetic induction unit and the second magnetic induction unit differentially sense a differential mode magnetic field generated by the current input component to be measured and generate a differential voltage signal to form an output signal of the current sensor; The current sensor further comprising an open-loop signal conditioning circuit, the open-loop signal conditioning circuit providing conditioning and amplification, temperature compensation, and linearity correction to the differential voltage signal; or further comprising a closed-loop signal conditioning circuit and a magnetic field feedback coil, wherein the closed-loop signal conditioning circuit, the magnetic field feedback coil, the first magnetic induction unit, and the second magnetic induction unit form a closed-loop magnetic field feedback structure; a current sensor, wherein after being amplified by the closed-loop signal conditioning circuit, the differential voltage signal passes through the magnetic field feedback coil to generate a feedback magnetic field to offset the differential mode magnetic field in opposite directions, and when dynamic balance of the magnetic fields is achieved, the first magnetic induction unit and the second magnetic induction unit operate at equal common mode magnetic field operating points, and then the feedback current of the magnetic field feedback coil is sampled to form an output signal of the magnetic induction module.

2. the first magnetic induction unit and the second magnetic induction unit are disposed on the same horizontal plane, and the horizontal plane is parallel to a plane on which the substrate is located; a vertical projection of the differential copper bar on the surface on which the substrate is located in a direction perpendicular to the surface on which the substrate is located covers the first magnetic induction unit and does not overlap the second magnetic induction unit; 2. The current sensor of claim 1, wherein a vertical projection of the copper bar for the first current shunt on the surface on which the substrate is located covers the first magnetic induction unit and the second magnetic induction unit, in a direction perpendicular to the surface on which the substrate is located, and a vertical projection of the copper bar for the second current shunt on the surface on which the substrate is located covers the first magnetic induction unit and the second magnetic induction unit.

3. 3. The current sensor according to claim 2, wherein the sensitivity direction of the first magnetic induction unit and the sensitivity direction of the second magnetic induction unit are the same as or opposite to the direction of the magnetic field generated by the current to be measured through the differential copper bar at the position of the first magnetic induction unit.

4. The current sensor of claim 1 , further comprising a housing, the measured current input component and the signal output component both fixedly disposed within the housing.

5. 2. The current sensor of claim 1, wherein the differential copper bar is disposed within the substrate.

6. the first magnetic induction unit comprises at least one magnetic resistance bridge arm, and the second magnetic induction unit comprises at least one magnetic resistance bridge arm; the magnetoresistive bridge arms of the first magnetic induction unit and the magnetoresistive bridge arms of the second magnetic induction unit are electrically connected to form a differential half-bridge structure or a differential full-bridge structure; 2. The current sensor of claim 1, wherein all magnetoresistive bridge arms have the same sensitivity direction, and the magnetoresistive bridge arms are formed by connecting at least one magnetoresistive sensing element in series and parallel.

7. The magnetic field feedback coil is integrated and disposed within the magnetic induction module, or 2. The current sensor of claim 1, wherein the magnetic field feedback coil is integrated and disposed within the substrate.

8. The first magnetic induction unit comprises a first half bridge or a first full bridge, and the second magnetic induction unit comprises a second half bridge or a second full bridge; 2. The current sensor of claim 1, wherein an output voltage difference between the bridge of the first magnetic induction unit and the bridge of the second magnetic induction unit generates the differential voltage signal.

9. the first half-bridge comprises two magnetoresistive bridge arms with opposite sensitivity directions, and the second half-bridge comprises two magnetoresistive bridge arms with opposite sensitivity directions, or the first full bridge comprises four magnetoresistive bridge arms, with two adjacent electrically connected magnetoresistive bridge arms having opposite sensitivity directions; the second full bridge comprises four magnetoresistive bridge arms, with two adjacent electrically connected magnetoresistive bridge arms having opposite sensitivity directions; 9. The current sensor of claim 8, wherein the magnetoresistive bridge arms are formed by one magnetoresistive sensing element or by two or more magnetoresistive sensing elements connected in series and parallel.

10. A current sensor, a current input component to be measured, comprising a first current shunt copper bar and a second current shunt copper bar connected in parallel; a signal output component electrically isolated from the current input component to be measured, the signal output component comprising a magnetic induction module and a substrate, the magnetic induction module being fixed on the substrate; a current to be measured flows through a cross section perpendicular to the first current shunt copper bar and the second current shunt copper bar, generating a magnetic field at the position of the magnetic induction module; the magnetic induction module comprises at least a first magnetic induction unit and a second magnetic induction unit, the first magnetic induction unit is located between the first current shunt copper bar and the second current shunt copper bar, the first magnetic induction unit and the second magnetic induction unit are located on the same horizontal plane, the horizontal plane is parallel to a surface on which the substrate is located, and in a direction perpendicular to the surface on which the substrate is located, an overlapping region of the vertical projections of the first current shunt copper bar and the second current shunt copper bar on the surface on which the substrate is located does not overlap with the second magnetic induction unit; the first magnetic induction unit and the second magnetic induction unit differentially sense a magnetic field generated by the measured current input component and generate a differential voltage signal to form an output signal of the current sensor; The current sensor further comprising an open-loop signal conditioning circuit, the open-loop signal conditioning circuit providing conditioning and amplification, temperature compensation, and linearity correction to the differential voltage signal; or further comprising a closed-loop signal conditioning circuit and a magnetic field feedback coil, wherein the closed-loop signal conditioning circuit, the magnetic field feedback coil, the first magnetic induction unit, and the second magnetic induction unit form a closed-loop magnetic field feedback structure; a current sensor, wherein after being amplified by the closed-loop signal conditioning circuit, the differential voltage signal passes through the magnetic field feedback coil to generate a feedback magnetic field to offset the differential mode magnetic field in opposite directions, and when dynamic balance of the magnetic fields is achieved, the first magnetic induction unit and the second magnetic induction unit operate at equal common mode magnetic field operating points, and then the feedback current of the magnetic field feedback coil is sampled to form an output signal of the magnetic induction module.

11. A current sensor, a current input component to be measured, which is composed of a current shunt copper bar and a differential copper bar, and the current shunt copper bar and the differential copper bar are arranged in the same direction; a signal output component electrically isolated from the current input component to be measured, the signal output component comprising a magnetic induction module and a substrate, the magnetic induction module being fixed on the substrate; A current to be measured flows through a cross section perpendicular to the current shunt copper bar and the differential copper bar, generating a magnetic field at the position of the magnetic induction module; the magnetic induction module includes at least a first magnetic induction unit and a second magnetic induction unit, the first magnetic induction unit and the second magnetic induction unit are located on the same horizontal plane, and the horizontal plane is parallel to a plane on which the substrate is located; the current shunt copper bar is disposed below the differential copper bar or above the magnetic induction module, and in a direction perpendicular to the plane on which the substrate is located, a vertical projection of the differential copper bar on the plane on which the substrate is located covers the first magnetic induction unit and does not overlap the second magnetic induction unit, and a vertical projection of the current shunt copper bar on the plane on which the substrate is located covers the first magnetic induction unit and the second magnetic induction unit; the first magnetic induction unit and the second magnetic induction unit differentially sense a magnetic field generated by the measured current input component and generate a differential voltage signal to form an output signal of the current sensor; The current sensor further comprising an open-loop signal conditioning circuit, the open-loop signal conditioning circuit providing conditioning and amplification, temperature compensation, and linearity correction to the differential voltage signal; or further comprising a closed-loop signal conditioning circuit and a magnetic field feedback coil, wherein the closed-loop signal conditioning circuit, the magnetic field feedback coil, the first magnetic induction unit, and the second magnetic induction unit form a closed-loop magnetic field feedback structure; a current sensor, wherein after being amplified by the closed-loop signal conditioning circuit, the differential voltage signal passes through the magnetic field feedback coil to generate a feedback magnetic field to offset the differential mode magnetic field in opposite directions, and when dynamic balance of the magnetic fields is achieved, the first magnetic induction unit and the second magnetic induction unit operate at equal common mode magnetic field operating points, and then the feedback current of the magnetic field feedback coil is sampled to form an output signal of the magnetic induction module.

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