Current sensor and electronic equipment

Abstract

The invention relates to the technical field of current measurement, and discloses a current sensor and electronic equipment. The current sensor comprises a parallel current collector and at least one magnetic resistance element, the parallel current collector comprises a first current collector and a second current collector which are coupled in parallel, and the extension direction of a first extension section in the first current collector is parallel to that of a second extension section in the second current collector; the at least one magnetic resistance element is positioned above the first extension section and / or the second extension section and is used for acquiring current information of the first current collector and / or the second current collector; the magnetic resistance element has a Wheatstone bridge structure and comprises two magnetic resistance blocks with opposite magnetic sensitive directions; the arrangement direction of the two magnetic resistance blocks is perpendicular to the first extension section, and a wire to be measured is coupled in series with the first current collector, the second current collector or the parallel current collector. The magnetic field distribution around the magnetic resistance element is improved through the parallel current collector structure, so that the magnetic resistance element can sense broadband current of more than 1MHz, and the beneficial effects of simple structure and easy implementation are achieved.

Description

Technical Field

[0001] This invention relates to the field of current measurement technology, and particularly to a current sensor and electronic device. Background Technology

[0002] A current sensor is a device for detecting current. It is generally used in actual current measurement and protection systems, such as photovoltaic, wind power, electric power, smart grid, railway electromechanical, aerospace, and new energy vehicles. As a key detection element, the current sensor plays a crucial role in ensuring the safety and stability of the system.

[0003] In highly integrated power electronic modules such as IGBT high-speed switching devices and GaN-based rectifier-inverter circuits, current monitoring elements are typically deployed on the PCB of the system module to monitor the module's operating status in real time, and their current frequency can reach over 1MHz.

[0004] Current sensors that utilize the tunneling magnetoresistive effect generally struggle to achieve wide-frequency current monitoring above 1MHz. Furthermore, for on-chip current traces at the MHz level, the resulting magnetic field distribution is severely affected by the skin effect, further limiting the bandwidth of TMR sensors. Summary of the Invention

[0005] The purpose of this invention is to propose a current sensor to improve the problem that existing current sensors have low bandwidth and are difficult to adapt to current detection above 1MHz.

[0006] A first aspect of the present invention provides a current sensor for detecting the current in a conductor under test, the current sensor comprising:

[0007] The parallel current collector consists of a first current collector and a second current collector coupled in parallel; the first extension section of the first current collector is parallel to the extension direction of the second extension section of the second current collector.

[0008] At least one magnetoresistive element is located above the first extension and / or the second extension for collecting current information of the first current collector and / or the second current collector;

[0009] The magnetoresistive element has a Wheatstone bridge structure, comprising two magnetoresistive blocks with opposite magnetic sensitivity directions; the arrangement direction of the two magnetoresistive blocks is perpendicular to the first extension segment;

[0010] The conductor under test is coupled in series with the first current collector, the second current collector, or the parallel current collector.

[0011] According to some embodiments of the present invention, the magnetoresistive element includes a first magnetoresistive arm, a second magnetoresistive arm, a third magnetoresistive arm and a fourth magnetoresistive arm coupled in sequence, wherein the first magnetoresistive arm and the third magnetoresistive arm have a first magnetic sensitivity direction, and the second magnetoresistive arm and the fourth magnetoresistive arm have a second magnetic sensitivity direction opposite to the first magnetic sensitivity direction.

[0012] The magnetoresistive element also includes a negative differential pin, a power supply pin, a positive differential pin, and a ground pin;

[0013] The negative differential pin is electrically coupled to the first magnetoresistive arm and the second magnetoresistive arm respectively; the ground pin is electrically coupled to the second magnetoresistive arm and the third magnetoresistive arm respectively; the positive differential pin is electrically coupled to the third magnetoresistive arm and the fourth magnetoresistive arm respectively; and the power supply pin is electrically coupled to the fourth magnetoresistive arm and the first magnetoresistive arm respectively.

[0014] According to some embodiments of the present invention, the two magnetoresistive blocks include a first magnetoresistive block and a second magnetoresistive block;

[0015] The first magnetoresistive block includes a first magnetoresistive arm, a third magnetoresistive arm, a first pad, a second pad, a third pad, and a fourth pad; the first magnetoresistive arm is electrically coupled to the power supply pin via the first pad and to the negative differential pin via the second pad; the third magnetoresistive arm is electrically coupled to the positive differential pin via the third pad and to the ground pin via the fourth pad;

[0016] The second magnetoresistive block includes a second magnetoresistive arm, a fourth magnetoresistive arm, a fifth pad, a sixth pad, a seventh pad, and an eighth pad; the fourth magnetoresistive arm is electrically coupled to the power supply pin via the seventh pad and to the positive differential pin via the eighth pad; the second magnetoresistive arm is electrically coupled to the negative differential pin via the fifth pad and to the ground pin via the sixth pad.

[0017] According to some embodiments of the present invention, the current sensor has a -3dB bandwidth greater than 1MHz.

[0018] According to some embodiments of the present invention, the distance between the first extension segment and the second extension segment is 24 to 48 mil; the distance between the second magnetoresistive block and the third magnetoresistive block is 24 to 48 mil.

[0019] According to some embodiments of the present invention, the at least one magnetoresistive element is a tunneling magnetoresistive element or a giant magnetoresistive element.

[0020] According to some embodiments of the present invention, the at least one magnetoresistive element includes a first magnetoresistive element and a second magnetoresistive element; each magnetoresistive arm in the first magnetoresistive element and each magnetoresistive arm in the second magnetoresistive element have the same resistance;

[0021] The first magnetoresistive element includes magnetoresistive block one and magnetoresistive block two with opposite magnetic sensing directions. The second magnetoresistive element includes magnetoresistive block three and magnetoresistive block four with opposite magnetic sensing directions. The magnetic sensing directions of magnetoresistive block two and magnetoresistive block three are the same. The magnetoresistive blocks one, two, three and four are arranged in a linear shape, and their arrangement direction is perpendicular to the first extension segment.

[0022] According to some embodiments of the present invention, the test lead is coupled in series with the parallel current collector;

[0023] The current sensor also includes a control module, which is electrically coupled to the first magnetoresistive element and the second magnetoresistive element, respectively, and is used to determine the current status of the conductor under test based on the sum of the output signals of the first magnetoresistive element and the second magnetoresistive element.

[0024] According to some embodiments of the present invention, the first current collector and the second current collector are flat conductive materials.

[0025] To achieve the above objectives, a second aspect of the present invention provides an electronic device comprising the aforementioned current sensor.

[0026] According to some embodiments of the present invention, the electronic device monitors the current in a high-frequency conductor via the current sensor.

[0027] Therefore, compared with the prior art, the present invention has the following beneficial effects:

[0028] The current sensor provided by this invention includes a parallel current collector and at least one magnetoresistive element. The parallel current collector includes a first current collector and a second current collector coupled in parallel. The first extension of the first current collector is parallel to the extension direction of the second extension of the second current collector. The at least one magnetoresistive element is located above the first extension and / or the second extension and is used to collect the current information of the first current collector and / or the second current collector. The magnetoresistive element has a Wheatstone bridge structure and includes two magnetoresistive blocks with opposite magnetic sensing directions. The arrangement direction of the two magnetoresistive blocks is perpendicular to the first extension. The conductor under test is coupled in series with the first current collector, the second current collector, or the parallel current collector. This invention improves the magnetic field distribution around the magnetoresistive element through the parallel current collector structure, enabling the magnetoresistive element to sense broadband currents above 1MHz, and achieves the beneficial effects of simple structure and ease of implementation. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the current sensor according to Embodiment 1 of the present invention;

[0031] Figure 2 This is a schematic diagram of the Wheatstone bridge of the first magnetoresistive element in Embodiment 1 of the present invention;

[0032] Figure 3 This is a schematic diagram of the Wheatstone bridge for the second magnetoresistive element in Embodiment 1 of the present invention;

[0033] Figure 4 This is a schematic diagram of the comparative current sensor of the present invention;

[0034] Figure 5 The amplitude of the current sensor in Embodiment 1 of the present invention and the comparative current sensor are shown as a function of frequency.

[0035] Figure 6 This is a simulation diagram of the magnetic field distribution around the current collector in the comparative current sensor of this invention;

[0036] Figure 7 This is a simulation diagram of the magnetic field distribution around the current collector in the current sensor of Embodiment 1 of the present invention;

[0037] Figure 8 This is a graph showing the change in magnetic induction intensity of magnetoresistive arm 1 and magnetoresistive arm 2 as a function of frequency in the current sensor of Embodiment 1 of the present invention.

[0038] Figure 9 The output voltage of the current sensor and the comparative current sensor in Embodiments 1 to 4 of the present invention are shown as curves of frequency variation.

[0039] Figure 10 The graphs show the sensitivity of the current sensors in Embodiments 1-4 of the present invention and the comparative current sensor as a function of frequency.

[0040] Figure 11 This is a schematic diagram of the current sensor in Embodiment 5 of the present invention;

[0041] Figure 12 This is a schematic diagram of the current sensor in Embodiment Six of the present invention.

[0042] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0043] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0044] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0045] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0046] A current sensor is a device for detecting current. It is generally used in actual current measurement and protection systems, such as photovoltaic, wind power, electric power, smart grid, railway electromechanical, aerospace, and new energy vehicles. As a key detection element, the current sensor plays a crucial role in ensuring the safety and stability of the system.

[0047] In highly integrated power electronic modules such as IGBT high-speed switching devices and GaN-based rectifier-inverter circuits, current monitoring elements are typically deployed on the PCB of the system module to monitor the module's operating status in real time, and their current frequency can reach over 1MHz.

[0048] Current sensors that utilize the tunneling magnetoresistive effect generally struggle to achieve wide-frequency current monitoring above 1MHz. Furthermore, for on-chip current traces at the MHz level, the resulting magnetic field distribution is severely affected by the skin effect, further limiting the bandwidth of TMR sensors.

[0049] The purpose of this invention is to provide a current sensor capable of achieving a bandwidth of 1MHz or higher.

[0050] like Figure 1 As shown, the current sensor of the first embodiment of the present invention includes a parallel current collector, a third current collector 5, a first magnetoresistive element 1 and a second magnetoresistive element 2, and the wire to be tested is coupled in series with the third current collector.

[0051] The parallel current collector of this invention includes a first current collector 3 and a second current collector 4 coupled in parallel; the first extension segment of the first current collector 3 and the second extension segment of the second current collector 4 are arranged in parallel. Both the first and second extension segments are flat. The distance d between the first and second current collectors is 32 mil.

[0052] In this embodiment of the invention, the third current collector 5 is connected in series with the parallel current collector. The load current of the third current collector is the sum of the currents of the first current collector 3 and the second current collector 4. That is, the current in the conductor under test is the sum of the currents of the first current collector 3 and the second current collector 4.

[0053] It should be understood that when the resistances of the first current collector 3 and the second current collector 4 are the same, the current in the first current collector and the second current collector should be half of the current in the third current collector.

[0054] It should be noted that the structure of the first current collector 3 is not limited to the first extension section, and may also include other extension sections that are connected in series with the first extension section; the structure of the second current collector 4 is not limited to the second extension section, and may also include other extension sections that are connected in series with the second extension section, which is not specifically limited here.

[0055] In this embodiment of the invention, the first magnetoresistive element 1 is located above the first extension section of the first current collector 3, and is used to sense the current information of the first current collector 3. The first magnetoresistive element 1 includes a magnetoresistive block 11, a magnetoresistive block 12, a negative differential pin 15, a ground pin 14, a positive differential pin 16, and a power supply pin 13. The magnetoresistive block 11 has a first magnetic sensing direction, and the magnetoresistive block 12 has a second magnetic sensing direction, which are parallel and opposite to each other. The arrangement direction of the magnetoresistive blocks 11 and 12 is perpendicular to the extension direction of the first extension section. The magnetoresistive block 12 is located in the middle of the first extension section, and the magnetoresistive block 1 is located on the side of the magnetoresistive block 12 away from the second extension section. To avoid affecting the magnetic field around the first extension section, the negative differential pin 15, the ground pin 14, the positive differential pin 16, and the power supply pin 13 are located on both sides of the first extension section, not directly above it.

[0056] In this embodiment of the invention, the second magnetoresistive element 2 is located above the second extension section of the second current collector 4, and is used to sense the current information of the second current collector 4. The second magnetoresistive element 2 includes a magnetoresistive block 3 21, a magnetoresistive block 4 22, a negative differential pin 25, a ground pin 24, a positive differential pin 26, and a power supply pin 23. The magnetoresistive block 3 21 has a second magnetic sensing direction, and the magnetoresistive block 4 22 has a first magnetic sensing direction. The arrangement direction of the magnetoresistive blocks 3 22 and 4 21 is perpendicular to the extension direction of the second extension section. The magnetoresistive block 3 22 is located in the middle of the second extension section, and the magnetoresistive block 4 21 is located on the side of the magnetoresistive block 3 22 away from the first extension section. To avoid affecting the magnetic field around the second extension section, the negative differential pin 25, the ground pin 24, the positive differential pin 26, and the power supply pin 23 are located on both sides of the second extension section, not directly above it.

[0057] It should be understood that the embodiments of the present invention include two magnetoresistive elements, respectively located above the first extension section of the first current collector and the second extension section of the second current collector, respectively sensing the current information of the first current collector and the second current collector. Since the test wire is connected in series with the third current collector, the current of the test wire and the sum of the currents of the first current collector and the second current collector are considered. The first extension section is parallel to the second extension section; the two magnetoresistive elements have the same structure, each including a first magnetoresistive block, a second magnetoresistive block, a power supply pin, a ground pin, a negative differential pin, and a positive differential pin, and the power supply pin, ground pin, negative differential pin, and positive differential pin are all located on both sides of the first extension section and the second extension section, and the arrangement direction of the first magnetoresistive block and the second magnetoresistive block is perpendicular to the extension direction of the first extension section. Furthermore, the first magnetoresistive block includes a first magnetoresistive arm and a third magnetoresistive arm with a first magnetic sensitivity direction, and the third magnetoresistive block includes a second magnetoresistive arm and a fourth magnetoresistive arm with a second magnetic sensitivity direction. The first magnetic sensitivity direction and the second magnetic sensitivity direction are opposite and parallel. The resistance of each magnetoresistive arm in the magnetoresistive element is the same when the magnetic field is zero. The first magnetoresistive arm, the second magnetoresistive arm, the third magnetoresistive arm and the fourth magnetoresistive arm are sequentially coupled to form a Wheatstone bridge.

[0058] like Figure 1-3 As shown, in the first magnetoresistive element 1, magnetoresistive block 11 includes magnetoresistive arm R1 and magnetoresistive arm R3 with a first magnetic sensitivity direction, and magnetoresistive block 12 includes magnetoresistive arm R2 and magnetoresistive arm R4 with a second magnetic sensitivity direction; magnetoresistive arm R1, magnetoresistive arm R2, magnetoresistive arm R3 and magnetoresistive arm R4 are sequentially coupled to form a Wheatstone bridge structure.

[0059] The first negative differential pin 15 is electrically coupled to magnetoresistive arm 1 R1 and magnetoresistive arm 2 R2 respectively; the ground pin 14 is electrically coupled to magnetoresistive arm 2 R2 and magnetoresistive arm 3 R3 respectively; the positive differential pin 16 is electrically coupled to magnetoresistive arm 3 R3 and magnetoresistive arm 4 R4 respectively; and the power supply pin 13 is electrically coupled to magnetoresistive arm 4 R4 and magnetoresistive arm 1 R1 respectively.

[0060] The magnetoresistive block 11 of this embodiment further includes pads A, B, C, and D; the magnetoresistive block 12 further includes pads E, F, G, and H; pads A and B are electrically coupled to both ends of magnetoresistive arm R1, pads C and D are electrically coupled to both ends of magnetoresistive arm R3, pads E and F are electrically coupled to both ends of magnetoresistive arm R2, and pads G and H are electrically coupled to both ends of magnetoresistive arm R4.

[0061] Furthermore, the first negative differential pin 15 is electrically coupled to pad B and pad E respectively; the ground pin 14 is electrically coupled to pad F and pad D respectively; the positive differential pin 16 is electrically coupled to pad C and pad H respectively; and the power supply pin 13 is electrically coupled to pad A and pad G respectively.

[0062] In the second magnetoresistive element 2, magnetoresistive block 4 22 includes magnetoresistive arm 6 R6 and magnetoresistive arm 8 R8 with a first magnetic sensitivity direction, and magnetoresistive block 3 21 includes magnetoresistive arm 5 R5 and magnetoresistive arm 7 R7 with a second magnetic sensitivity direction. Magnetoresistive arm 5 R5, magnetoresistive arm 6 R6, magnetoresistive arm 7 R7 and magnetoresistive arm 8 R8 are coupled in sequence to form a Wheatstone bridge structure as shown in Figure 3.

[0063] The second negative differential pin 25 is electrically coupled to magnetoresistive arm 5 R5 and magnetoresistive arm 6 R6 respectively; the second ground pin 24 is electrically coupled to magnetoresistive arm 6 R6 and magnetoresistive arm 7 R7 respectively; the second positive differential pin 26 is electrically coupled to magnetoresistive arm 7 R7 and magnetoresistive arm 8 R8 respectively; and the second power supply pin 23 is electrically coupled to magnetoresistive arm 5 R5 and magnetoresistive arm 8 R8 respectively.

[0064] The second magnetoresistive element 2 also includes magnetoresistive block 3 22, which includes pads I, J, K, and L; and magnetoresistive block 4 includes pads M, N, O, and P. Pads I and J are electrically coupled to both ends of magnetoresistive arm 5 R5, respectively; pads K and L are electrically coupled to both ends of magnetoresistive arm 7 R7, respectively; pads M and N are electrically coupled to both ends of magnetoresistive arm 6 R6, respectively; and pads O and P are electrically coupled to both ends of magnetoresistive arm 8 R8, respectively.

[0065] Furthermore, the second negative differential pin 25 is electrically coupled to pad N and pad I respectively; the second ground pin 24 is electrically coupled to pad J and pad P respectively; the second positive differential pin 26 is electrically coupled to pad O and pad P respectively; and the second power supply pin 23 is electrically coupled to pad M and pad K respectively.

[0066] It should be understood that the first magnetoresistive element 1 and the second magnetoresistive element 2 are two magnetoresistive elements placed at 180 degrees. Given that the magnetic induction intensity is lower at the position near the second extension block in the first extension block, the second magnetoresistive element is preferably located in the middle position of the first extension block; given that the magnetic induction intensity is lower at the position near the first extension block in the second extension block, the third magnetoresistive element is preferably located in the middle position of the first extension block.

[0067] The current sensor in this embodiment of the invention also includes a control module (not shown), which is electrically coupled to the first magnetoresistive element 1 and the second magnetoresistive element 2 respectively, and is used to determine the current of the conductor to be measured based on the sum of the output signals of the first magnetoresistive element and the second magnetoresistive element 2.

[0068] In this embodiment of the invention, magnetoresistive block 11, magnetoresistive block 22, magnetoresistive block 32, and magnetoresistive block 41 are arranged sequentially, with their arrangement direction perpendicular to the extension direction of the first extension segment. When the arrangement direction of magnetoresistive block 1 and magnetoresistive block 2 is parallel to the extension direction of the first extension segment, the bandwidth of the current sensor at high frequencies does not increase significantly.

[0069] Figure 4 This is a schematic diagram of a comparative current sensor with only one current collector. The comparative current sensor includes only a flat current collector and a magnetoresistive element located above the current collector. The magnetoresistive element has the same structure as the first magnetoresistive element in the embodiment of the present invention, and will not be described in detail here.

[0070] Compared to the comparative current sensor, the current sensor of this embodiment has a -3dB bandwidth higher than 1MHz, and can be used for measuring high-frequency currents above 1MHz. Specifically, different frequencies of current are provided to the conductor under test, and the amplitude of the current sensor of this embodiment and the comparative current sensor is observed to change with frequency. Figure 5 As shown, the -3dB frequency of the current sensor in this embodiment is significantly higher than that of the comparative current sensor. The current sensor in this embodiment corresponds to a frequency of approximately 1.5MHz at an amplitude of -3dB; the comparative current sensor corresponds to a frequency of 1MHz at the -3dB amplitude point. This demonstrates that the current sensor in this embodiment improves the sensor's bandwidth and achieves a bandwidth exceeding 1MHz.

[0071] By adjusting the frequency of the load current in the conductor under test, simulations were performed on the magnetic field surrounding the current collector in this embodiment and the comparative current collector. The results are as follows: Figure 6-8 As shown.

[0072] like Figure 6 As shown, when the current in the conductor to be measured of the comparative current sensor is 0.1A and the frequency is 1MHz, due to the skin effect, the magnetic field strength at both ends of the current collector is higher and the magnetic field strength inside the current collector is lower.

[0073] It should be understood that when direct current passes through a conductor, the current distribution on any cross-section inside the current collector is uniform; when alternating current is passed through the current collector, the current inside the current collector will generate a changing magnetic field. This changing magnetic field will induce eddy currents inside the current collector. Due to the effect of the eddy currents, the current density distribution on the cross-section will be uneven, and the current will concentrate on the outer surface of the current collector, which is the skin effect.

[0074] like Figure 7 As shown, in this embodiment of the invention, when the current of the conductor under test is 0.1A and the frequency is 1MHz, the current in the first current collector and the second current collector are both 0.05A and the frequency is 1MHz. The magnetic field strength is higher on the side of the two current collectors that is farther away from each other, and lower on the side that is closer to each other.

[0075] like Figure 8 As shown, in this embodiment of the invention, when the current of the conductor under test is 0.1A, the magnetic induction intensity of the first reluctance arm is lower than that of the second reluctance arm. Furthermore, the magnetic induction intensity of the first reluctance arm increases slowly with increasing frequency, while the magnetic induction intensity of the second reluctance arm decreases slowly with increasing frequency. This indicates that under the influence of current, the magnetic induction intensities of each arm in the first reluctance element are different, and the difference in magnetic induction intensity changes with the current frequency.

[0076] Assuming R is the resistance of each magnetoresistive bridge arm in the first and second magnetoresistive elements of this embodiment of the invention when there is zero magnetic field, ΔR1 is the increase or decrease in resistance of each magnetoresistive bridge arm in the first magnetoresistive element; ΔR2 is the increase or decrease in resistance of each magnetoresistive bridge arm in the second magnetoresistive element, V cc The supply voltage for the first and second magnetoresistive elements; under the action of the conductor under test, the output voltage and input voltage of the current sensor in this embodiment of the invention conform to the formula:

[0077]

[0078] Assume K B Let B1 be the sensitivity of the first and second magnetoresistive elements to the magnetic field, B2 be the magnetic flux density of each arm of the first magnetoresistive element, and B2 be the magnetic flux density of each arm of the second magnetoresistive element; ΔR1 satisfies the formula: ΔR1=K B B1 and ΔR2 satisfy the formula: ΔR2=K B ·B2. Therefore, the output voltage of the current sensor conforms to the formula:

[0079]

[0080] By adjusting the current frequency of the conductor under test, simulation analysis was conducted to determine the changes in magnetic induction intensity of the first and second magnetoresistive arms in the comparative current sensor and the current sensors of the first to fourth embodiments of this invention at different current frequencies. The current sensors of the first, second, third, and fourth embodiments employ the same structure, differing only in the spacing between the current collectors. The distances between the first and second current collectors in the current sensors of the first, second, third, and fourth embodiments are 36 mil, 24 mil, 30 mil, and 48 mil, respectively.

[0081] The values ​​of magnetic flux density B1 of magnetoresistive arm one and magnetic flux density B2 of magnetoresistive arm two at various current frequencies, as well as the values ​​of R and K, are compared with those of the comparative current sensor and the current sensor of the first to fourth embodiments of the present invention. B Substitute the values ​​of Vcc and Vcc into the formula: Get as Figure 9 The curves showing the output voltage of the comparative current sensor and the current sensor of the first to fourth embodiments of the present invention as a function of frequency are shown.

[0082] like Figure 9 As shown, the output voltage of the comparative current sensor decreases with increasing current frequency; however, the output voltage of the current sensors in embodiments one through four of this invention does not significantly increase or decrease with increasing current frequency, and the output voltage value is related to the distance between the current collectors. When the current distance is 24–36 mil, the output voltage decreases with increasing current collector distance; when it is 36–48 mil, the output voltage remains essentially unchanged with increasing current collector distance. Therefore, compared to the comparative current sensor, the output voltage of the current sensor in these embodiments of the invention does not significantly change with increasing frequency, exhibiting higher stability. Furthermore, the preferred distance between the two current collectors is 24–36 mil.

[0083] Apply currents of different frequencies to the conductor under test and observe how the sensitivity of the comparative current sensor and the current sensor of Embodiment 1 of this invention changes with the current frequency. Figure 10 As shown.

[0084] like Figure 10 As shown, the sensitivity of the current sensor in Embodiment 1 of the present invention is significantly higher than that of the comparative current sensor, and the difference in sensitivity between the current sensor in Embodiment 1 and the comparative current sensor increases at high-frequency currents. Therefore, the current sensor in this embodiment of the present invention achieves higher sensitivity.

[0085] like Figure 11As shown, the current sensor provided in the fifth embodiment of the present invention includes a parallel current collector, a third current collector 5, and a first magnetoresistive element 1. The parallel current collector includes a first current collector 3 and a second current collector 4 coupled in parallel. The first extension of the first current collector 3 is parallel to the second extension of the second current collector 4, and the first magnetoresistive element 1 is located above the first current collector 3. Compared with the current sensor of the first embodiment, the current sensor of the present invention only lacks the first magnetoresistive element.

[0086] In this embodiment of the invention, only the first magnetoresistive element is configured to sense the current information of the first current collector. Therefore, the current sensor of this embodiment can be used to measure the current information of the test wire that is connected in series with the first current collector. The 3dB frequency of the current sensor of this embodiment is higher than 1.0MHz.

[0087] like Figure 12 As shown, the current sensor provided in the sixth embodiment of the present invention includes a parallel current collector, a third current collector 5, and a second magnetoresistive element 2. The parallel current collector includes a first current collector 3 and a second current collector 4 coupled in parallel. The first extension of the first current collector 3 is parallel to the second extension of the second current collector 4, and the fourth magnetoresistive element 7 is located above the second current collector 4. Compared with the current sensor of the first embodiment, the current sensor of this embodiment lacks only the first magnetoresistive element.

[0088] In this embodiment of the invention, only the second magnetoresistive element is configured to sense the current information of the second current collector. Therefore, the current sensor in this embodiment of the invention can be used to measure the current information of the test wire that is connected in series with the second current collector.

[0089] In summary, the current sensor provided by this invention includes a parallel current collector and at least one magnetoresistive element. The parallel current collector includes a first current collector and a second current collector coupled in parallel. The first extension of the first current collector is parallel to the extension direction of the second extension of the second current collector. The at least one magnetoresistive element is located above the first extension and / or the second extension and is used to collect the current information of the first current collector and / or the second current collector. The magnetoresistive element has a Wheatstone bridge structure and includes two magnetoresistive blocks with opposite magnetic sensitivity directions. The arrangement direction of the two magnetoresistive blocks is perpendicular to the first extension. The conductor under test is connected in series with the first current collector, the second current collector, or the parallel current collector. This invention improves the magnetic field distribution around the magnetoresistive element through the parallel current collector structure, enabling the magnetoresistive element to sense broadband currents above 1MHz, and achieves the beneficial effects of simple structure and ease of implementation.

[0090] The above description is merely an exemplary embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention specification and drawings under the technical concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A current sensor, characterized in that: Used to detect the current condition of the conductor to be tested; The current sensor comprises: A parallel current collector, comprising a first current collector and a second current collector coupled in parallel; the extension direction of the first extension section in the first current collector is parallel to the extension direction of the second extension section in the second current collector; at least one magnetoresistive element, located above the first extension section and / or the second extension section, and used to collect current information of the first current collector and / or the second current collector; The magnetoresistive element has a Wheatstone bridge structure, including two magnetoresistive blocks with opposite magnetic sensitivity directions; the arrangement direction of the two magnetoresistive blocks is perpendicular to the first extension section; The wire to be tested is coupled in series with the first current collector, the second current collector or the parallel current collector.

2. The current sensor according to claim 1, characterized in that: The magnetoresistive element comprises a first magnetoresistive arm, a second magnetoresistive arm, a third magnetoresistive arm and a fourth magnetoresistive arm coupled in sequence, the first magnetoresistive arm and the third magnetoresistive arm having a first magnetic sensitive direction, the second magnetoresistive arm and the fourth magnetoresistive arm having a second magnetic sensitive direction opposite to the first magnetic sensitive direction; The magnetoresistive element further includes a negative differential pin, a power pin, a positive differential pin and a ground pin; The negative differential pin is electrically coupled to the first magnetic resistance arm and the second magnetic resistance arm respectively; the ground pin is electrically coupled to the second magnetic resistance arm and the third magnetic resistance arm respectively; the positive differential pin is electrically coupled to the third magnetic resistance arm and the fourth magnetic resistance arm respectively; the power pin is electrically coupled to the fourth magnetic resistance arm and the first magnetic resistance arm respectively.

3. The current sensor according to claim 2, characterized in that: The two magnetoresistive blocks include a first magnetoresistive block and a second magnetoresistive block; The first magnetic resistance block includes the first magnetic resistance arm, the third magnetic resistance arm, a first pad, a second pad, a third pad and a fourth pad; the first magnetic resistance arm is electrically coupled to the power pin via the first pad, and is electrically coupled to the negative differential pin via the second pad; the third magnetic resistance arm is electrically coupled to the positive differential pin via the third pad, and is electrically coupled to the ground pin via the fourth pad; The second magnetoresistive block includes the second magnetoresistive arm, the fourth magnetoresistive arm, a fifth pad, a sixth pad, a seventh pad and an eighth pad; the fourth magnetoresistive arm is electrically coupled to the power pin via the seventh pad, and is electrically coupled to the positive differential pin via the eighth pad; the second magnetoresistive arm is electrically coupled to the negative differential pin via the fifth pad, and is electrically coupled to the ground pin via the sixth pad.

4. The current sensor according to claim 1, characterized in that: The -3dB bandwidth of the current sensor is higher than 1 MHz.

5. The current sensor according to claim 1, characterized in that: The distance between the first extension section and the second extension section is 24 to 48 mils; the distance between the second magnetoresistive block and the third magnetoresistive block is 24 to 48 mils.

6. The current sensor according to claim 1, characterized in that: The at least one magnetoresistive element is a tunneling magnetoresistive element or a giant magnetoresistive element.

7. The current sensor according to any one of claims 1 to 6, characterized in that: The at least one magnetoresistive element comprises a first magnetoresistive element and a second magnetoresistive element; each magnetoresistive arm in the first magnetoresistive element and each magnetoresistive arm in the second magnetoresistive element have the same resistance; The first magnetoresistance element includes a magnetoresistance block 1 and a magnetoresistance block 2 having opposite magnetic sensitivity directions to each other, and the second magnetoresistance element includes a magnetoresistance block 3 and a magnetoresistance block 4 having opposite magnetic sensitivity directions to each other, and the magnetoresistance block 2 has the same magnetic sensitivity direction as the magnetoresistance block 3; the magnetoresistance block 1, the magnetoresistance block 2, the magnetoresistance block 3 and the magnetoresistance block 4 are arranged linearly, and their arrangement direction is perpendicular to the first extension section.

8. The current sensor according to claim 7, characterized in that: The conductor to be tested is coupled in series with the parallel current collector; The current sensor also includes a control module, which is electrically coupled to the first magnetoresistive element and the second magnetoresistive element respectively, and is used to determine the current condition of the conductor to be measured according to the sum of the output signals of the first magnetoresistive element and the second magnetoresistive element.

9. The current sensor according to claim 1, characterized in that: The first current collector and the second current collector are flat conductive materials.

10. An electronic device, characterized in that: The electronic device comprises the current sensor according to any one of claims 1 to 9.

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