Current sensor and electronic equipment

Abstract

The present invention relates to the field of current measurement technology, and discloses a current sensor and electronic equipment. The current sensor includes parallel current collectors and at least one magnetoresistive element. The parallel current collectors include a first current collector and a second current collector coupled in parallel, and 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 is located above the first extension section and / or the second extension section, and is 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, and the conductor to be measured is coupled in series with the first current collector, the second current collector or the parallel current collector. The present invention improves the magnetic field distribution around the magnetoresistive element through the parallel current collector structure, so that the magnetoresistive element can sense broadband currents above 1 MHz, and achieves the beneficial effects of simple structure and easy implementation.

Description

Technical Field

[0001] The present invention relates to the technical field of current measurement, and in particular to a current sensor and electronic equipment. Background Art

[0002] A current sensor is a device that detects current and is generally used in actual current measurement and protection systems, such as photovoltaics, wind power, electricity, smart grids, railway electromechanical, aerospace, new energy vehicles and other fields. As the main detection element, the current sensor plays a vital 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 usually deployed on the system module's PCB to monitor the module's operating status in real time. The current frequency can reach above 1MHz.

[0004] Current sensors using the tunnel magnetoresistance effect generally have difficulty achieving wide-band current monitoring above 1 MHz. Moreover, for MHz-level on-chip current traces, the magnetic field distribution generated will be severely affected by the skin effect, further limiting the bandwidth of the TMR sensor. Summary of the Invention

[0005] The purpose of the present invention is to provide a current sensor to improve the problem that the existing current sensor has a low bandwidth and is difficult to adapt to current detection above 1 MHz.

[0006] A first aspect of the present invention provides a current sensor for detecting the current of a conductor to be measured, the current sensor comprising:

[0007] A parallel current collector, comprising a first current collector and a second current collector coupled in parallel; the first extension section of the first current collector and the second extension section of the second current collector extending in parallel;

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

[0009] 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;

[0010] The wire to be tested 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 magnetically sensitive direction, and the second magnetoresistive arm and the fourth magnetoresistive arm have a second magnetically sensitive direction opposite to the first magnetically sensitive direction;

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

[0013] 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; and the power pin is electrically coupled to the fourth magnetic resistance arm and the first magnetic resistance 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 the first magnetoresistive arm, the 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 pin via the first pad, and is electrically coupled 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 is electrically coupled to the ground pin via the fourth pad;

[0016] 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.

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

[0018] According to some embodiments of the present invention, the distance between the first extension section and the second extension section is 24 to 48 mils.

[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 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.

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

[0023] The current sensor further includes a control module electrically coupled to the first magnetoresistive element and the second magnetoresistive element, respectively, for determining the current condition of the conductor to be measured 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 object, a second aspect of the present invention provides an electronic device, which includes the above current sensor.

[0026] According to some embodiments of the present invention, the electronic device monitors the current condition of the high-frequency wire through the current sensor.

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

[0028] The current sensor provided by the present invention includes parallel current collectors and at least one magnetoresistive element. The parallel current collectors include a first current collector and a second current collector coupled in parallel, wherein the first extension section of the first current collector extends in parallel with the second extension section of the second current collector. At least one magnetoresistive element is located above the first extension section and / or the second extension section and is used to collect current information from 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 two magnetoresistive blocks are arranged perpendicular to the first extension section, and the conductor to be measured is coupled in series with the first current collector, the second current collector, or the parallel current collector. The present invention improves the magnetic field distribution around the magnetoresistive element through the parallel current collector structure, enabling the magnetoresistive element to sense broadband currents exceeding 1 MHz, while achieving the beneficial effects of a simple structure and ease of implementation. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

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

[0031] Figure 2 Schematic diagram of a Wheatstone bridge of a first magnetoresistive element according to a first embodiment of the present invention;

[0032] Figure 3 Schematic diagram of a Wheatstone bridge of a second magnetoresistive element according to a first embodiment of the present invention;

[0033] Figure 4 Schematic diagram of the structure of the comparative current sensor of the present invention;

[0034] Figure 5 Graph showing the amplitude variation with frequency of the current sensor of the first embodiment of the present invention and the current sensor of the comparative example;

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

[0036] Figure 7 This is a simulation diagram of the magnetic field distribution around the current collector in the current sensor according to the first embodiment of the present invention;

[0037] Figure 8 This is a graph showing how the magnetic induction intensity of the first and second magnetoresistive arms of the current sensor in accordance with the first embodiment of the present invention changes with frequency;

[0038] Figure 9 Graphs showing output voltage variation versus frequency for the current sensors of Examples 1 to 4 of the present invention and a comparative current sensor;

[0039] Figure 10 Graphs showing sensitivity variations with frequency for the current sensors of Examples 1 to 4 of the present invention and a comparative current sensor;

[0040] Figure 11 This is a schematic structural diagram of a current sensor according to a fifth embodiment of the present invention;

[0041] Figure 12 Schematic diagram of the structure of the current sensor according to the sixth embodiment of the present invention.

[0042] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0043] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall 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 position relationship, movement status, etc. between the components under a certain specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0045] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of such features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or solutions that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0046] A current sensor is a device that detects current and is generally used in actual current measurement and protection systems, such as photovoltaics, wind power, electricity, smart grids, railway electromechanical, aerospace, new energy vehicles and other fields. As the main detection element, the current sensor plays a vital 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 usually deployed on the system module's PCB to monitor the module's operating status in real time. The current frequency can reach above 1MHz.

[0048] Current sensors using the tunnel magnetoresistance effect generally have difficulty achieving wide-band current monitoring above 1 MHz. Moreover, for MHz-level on-chip current traces, the magnetic field distribution generated will be severely affected by the skin effect, further limiting the bandwidth of the TMR sensor.

[0049] An object of the embodiments of the present invention is to provide a current sensor that can achieve a bandwidth of more than 1 MHz.

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

[0051] The parallel current collectors of this embodiment include a first current collector 3 and a second current collector 4 coupled in parallel. The first extension section of the first current collector 3 and the second extension section of the second current collector 4 are arranged in parallel. Both the first extension section and the second extension section are flat. The distance d between the first and second current collectors is 32 mils.

[0052] The third current collector 5 of the embodiment of the present invention is coupled 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. In other words, the current of the conductor to be tested 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 currents of the first current collector and the second current collector should be half of the current of 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 segment, but may also include other extension segments coupled in series with the first extension segment; the structure of the second current collector 4 is not limited to the second extension segment, but may also include other extension segments coupled in series with the second extension segment, which is not specifically limited here.

[0055] The first magnetoresistive element 1 of the embodiment of the present invention 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 2 12, a negative differential pin 15, a ground pin 14, a positive differential pin 16, and a power pin 13. The magnetoresistive block 11 has a first magnetic sensitivity direction, and the magnetoresistive block 2 12 has a second magnetic sensitivity direction, and the first magnetic sensitivity direction is antiparallel to the second magnetic sensitivity direction. The arrangement direction of the magnetoresistive block 11 and the magnetoresistive block 2 12 is perpendicular to the extension direction of the first extension section. The magnetoresistive block 2 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 2 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 pin 13 are located on both sides of the first extension section, and not directly above the first extension section.

[0056] The second magnetoresistive element 2 of the embodiment of the present invention is located above the second extension section in 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 three 21, a magnetoresistive block four 22, a negative differential pin two 25, a ground pin two 24, a positive differential pin two 26 and a power pin two 23. The magnetoresistive block three 21 has a second magnetic sensitive direction, and the magnetoresistive block four 22 has a first magnetic sensitive direction. The arrangement direction of the magnetoresistive block three 22 and the magnetoresistive block four 21 is perpendicular to the extension direction of the second extension section. The magnetoresistive block three 22 is located in the middle of the second extension section, and the magnetoresistive block four 21 is located on the side of the magnetoresistive block three 22 away from the first extension section. In order to avoid affecting the magnetic field around the second extension section, the negative differential pin two 25, the ground pin two 24, the positive differential pin two 26 and the power pin two 23 are located on both sides of the second extension section, and are not located directly above the second extension section.

[0057] It should be understood that the embodiment of the present invention includes two magnetoresistive elements, which are respectively located above the first extension section in the first current collector and the second extension section in the second current collector, and respectively sense the current information of the first current collector and the second current collector. Since the conductor to be measured is coupled in series with the third current collector, the current of the conductor to be measured and the sum of the currents of the first current collector and the second current collector. The first extension section is parallel to the second extension section; the two magnetoresistive elements have the same structure, both including a first magnetoresistive block, a second magnetoresistive block, a power pin, a ground pin, a negative differential pin, and a positive differential pin, and the power pin, the ground pin, the negative differential pin, and the 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 having a first magnetically sensitive direction, and the second magnetoresistive block includes a second magnetoresistive arm and a fourth magnetoresistive arm having a second magnetically sensitive direction. The first magnetically sensitive direction is antiparallel to the second magnetically sensitive direction, and each magnetoresistive arm in the magnetoresistive element has the same resistance when the magnetic field is zero. The first, second, third, and fourth magnetoresistive arms are sequentially coupled to form a Wheatstone bridge.

[0058] like Figure 1-3 As shown, the magnetoresistive block 11 in the first magnetoresistive element 1 includes a magnetoresistive arm 1 R1 and a magnetoresistive arm 3 R3 having a first magnetic sensitive direction, and the magnetoresistive block 2 12 includes a magnetoresistive arm 2 R2 and a magnetoresistive arm 4 R4 having a second magnetic sensitive direction; the magnetoresistive arm 1 R1, the magnetoresistive arm 2 R2, the magnetoresistive arm 3 R3 and the magnetoresistive arm 4 R4 are coupled in sequence to form a Wheatstone bridge structure.

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

[0060] The magnetoresistive block 11 of the embodiment of the present invention further includes pad A, pad B, pad C, and pad D; the magnetoresistive block 2 12 further includes pad E, pad F, pad G, and pad H; pad A and pad B are respectively electrically coupled to the two ends of the magnetoresistive arm 1 R1, pad C and pad D are respectively electrically coupled to the two ends of the magnetoresistive arm 3 R3, pad E and pad F are respectively electrically coupled to the two ends of the magnetoresistive arm 2 R2, and pad G and pad H are respectively electrically coupled to the two ends of the magnetoresistive arm 4 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 pin 13 is electrically coupled to pad A and pad G respectively.

[0062] In the second magnetoresistive element 2, the magnetoresistive block four 22 includes a magnetoresistive arm six R6 and a magnetoresistive arm eight R8 having a first magnetic sensitive direction, and the magnetoresistive block three 21 includes a magnetoresistive arm five R5 and a magnetoresistive arm seven R7 having a second magnetic sensitive direction. The magnetoresistive arm five R5, the magnetoresistive arm six R6, the magnetoresistive arm seven R7 and the magnetoresistive arm eight R8 are coupled in sequence to form a Wheatstone bridge structure as shown in 3.

[0063] The second negative differential pin 25 is electrically coupled to the magnetic resistance arm five R5 and the magnetic resistance arm six R6 respectively; the second ground pin 24 is electrically coupled to the magnetic resistance arm six R6 and the magnetic resistance arm seven R7 respectively; the second positive differential pin 26 is electrically coupled to the magnetic resistance arm seven R7 and the magnetic resistance arm eight R8 respectively, and the power supply pin two 23 is electrically coupled to the magnetic resistance arm five R5 and the magnetic resistance arm eight R8 respectively.

[0064] The magnetoresistive block three 22 in the second magnetoresistive element 2 also includes pad I, pad J, pad K, and pad L, and the magnetoresistive block four also includes pad M, pad N, pad O, and pad P; pad I and pad J are electrically coupled to the two ends of the magnetoresistive arm five R5, respectively, pad K and pad L are electrically coupled to the two ends of the magnetoresistive arm seven R7, respectively, pad M and pad N are electrically coupled to the two ends of the magnetoresistive arm six R6, respectively, pad O and pad P are electrically coupled to the two ends of the magnetoresistive arm eight R8.

[0065] Furthermore, the second negative differential pin 25 is electrically coupled to pad N and pad I respectively; the ground pin 24 is electrically coupled to pad J and pad P respectively; the positive differential pin 26 is electrically coupled to pad O and pad P respectively; and the power 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 positioned 180 degrees apart. Given that the magnetic induction intensity in the first extension block near the second extension block is lower, magnetoresistive block 2 is preferably located in the middle of the first extension block. Given that the magnetic induction intensity in the second extension block near the first extension block is lower, magnetoresistive block 3 is preferably located in the middle of the second extension block.

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

[0068] In the embodiment of the present invention, magnetoresistive blocks 11, 12, 22, and 21 are arranged in sequence, with the arrangement direction perpendicular to the extension direction of the first extension section. When magnetoresistive blocks 1 and 2 are arranged parallel to the extension direction of the first extension section, the bandwidth of the current sensor at high frequencies is not significantly increased.

[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. This magnetoresistive element has the same structure as the first magnetoresistive element in the embodiment of the present invention and is not described in detail here.

[0070] Compared with the comparative current sensor, the -3dB bandwidth of the current sensor of the embodiment of the present invention is higher than 1MHz, and it can be used to measure high-frequency currents above 1MHz. Specifically, currents of different frequencies are provided to the conductor to be measured, and the amplitude changes of the current sensor of the embodiment of the present invention and the comparative current sensor with frequency are observed. Figure 5 As shown, the -3dB frequency of the current sensor according to the present invention is much higher than that of the comparative current sensor. The frequency corresponding to the -3dB amplitude point for the current sensor according to the present invention is approximately 1.5MHz; the frequency corresponding to the -3dB amplitude point for the comparative current sensor is 1MHz. This demonstrates that the current sensor according to the present invention improves the sensor's bandwidth, achieving a bandwidth exceeding 1MHz.

[0071] Adjust the frequency of the load current in the wire to be tested, and simulate the magnetic field around the current collector of the embodiment of the present invention and the current collector of the comparative example. The results are as follows: Figure 6-8 shown.

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

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

[0074] like Figure 7 As shown, in the embodiment of the present invention, when the current of the conductor to be tested 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 on the side of the two current collectors far away from each other is higher, and the magnetic field strength on the side close to each other is lower.

[0075] like Figure 8 As shown, when the current of the measured conductor in this embodiment of the present invention is 0.1A, the magnetic induction intensity of reluctance arm 1 is lower than that of reluctance arm 2. Furthermore, the magnetic induction intensity of reluctance arm 1 increases slowly with increasing frequency, while the magnetic induction intensity of reluctance arm 2 decreases slowly with increasing frequency. This indicates that under the action of current, the magnetic induction intensity of each bridge arm in the first reluctance element is different, and the difference in magnetic induction intensity varies with changes in current frequency.

[0076] Assume that R is the resistance of each magnetoresistive bridge arm in the first magnetoresistive element and the second magnetoresistive element in the embodiment of the present invention at zero magnetic field, ΔR1 is the resistance increase or resistance decrease of each magnetoresistive bridge arm in the first magnetoresistive element; ΔR2 is the resistance increase or resistance decrease of each magnetoresistive bridge arm in the second magnetoresistive element, V cc is the supply voltage of the first magnetoresistive element and the second magnetoresistive element; under the action of the conductor to be measured, the output voltage and input voltage of the current sensor of the embodiment of the present invention meet the formula:

[0077]

[0078] Assume K B is the sensitivity of the first magnetoresistive element and the second magnetoresistive element to the magnetic field, B1 is the magnetic induction intensity of each magnetoresistive bridge arm in the first magnetoresistive element, and B2 is the magnetic induction intensity of each magnetoresistive bridge arm in the second magnetoresistive element; ΔR1 satisfies the formula: ΔR1=K B B1, ΔR2 satisfies the formula: ΔR2=K B B2. The output voltage and input voltage of the current sensor then conform to the formula:

[0079]

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

[0081] The values ​​of the magnetic induction intensity B1 of the first magnetic resistance arm and the magnetic induction intensity B2 of the second magnetic resistance arm at each current frequency in the current sensor of the comparative example and the current sensors of the first to fourth embodiments of the present invention, as well as the R value, K B Substitute the Vcc value into the formula: Get as Figure 9 The output voltage variation curves of the comparative current sensor and the current sensors of the first to fourth embodiments of the present invention are shown.

[0082] like Figure 9 As shown, the output voltage of the comparative current sensor decreases with increasing current frequency; the output voltage of the current sensors of Examples 1 to 4 of the present invention does not increase or decrease significantly with increasing current frequency, and the output voltage value is related to the collector spacing. When the current collector spacing is 24 to 36 mil, the output voltage decreases with increasing collector spacing; when the current collector spacing is 36 to 48 mil, the output voltage basically does not change with increasing collector spacing. Therefore, compared with the comparative current sensor, the output voltage of the current sensor of the embodiment of the present invention basically does not significantly change with increasing frequency, and it has higher stability. At the same time, the spacing between the two collectors is preferably 24 to 36 mil.

[0083] Apply currents of different frequencies to the conductor to be tested, and observe how the sensitivity of the comparative current sensor and the current sensor of the first embodiment of the present invention changes with the current frequency. Figure 10 shown.

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

[0085] like Figure 11As shown, the current sensor provided by the fifth embodiment of the present invention includes parallel current collectors, a third current collector 5, and a first magnetoresistive element 1. The parallel current collectors include 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. 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 this embodiment of the present invention only lacks the first magnetoresistive element.

[0086] In this embodiment of the present invention, only the first magnetoresistive element is provided to sense the current information of the first current collector. Therefore, the current sensor according to this embodiment of the present invention can be used to measure the current information of a conductor to be measured that is coupled in series with the first current collector. The 3dB frequency of the current sensor according to this embodiment of the present invention is higher than 1.0MHz.

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

[0088] In the embodiment of the present invention, only the second magnetoresistive element is provided to sense the current information of the second current collector. Therefore, the current sensor in the embodiment of the present invention can be used to measure the current information of the conductor to be measured that is coupled in series with the second current collector.

[0089] In summary, the current sensor provided by the embodiment of the present invention includes parallel current collectors and at least one magnetoresistive element. The parallel current collectors include a first current collector and a second current collector coupled in parallel, wherein the first extension section of the first current collector extends in parallel with the second extension section of the second current collector. At least one magnetoresistive element is located above the first extension section and / or the second extension section and is used to collect 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 section, and the conductor to be measured is coupled in series with the first current collector, the second current collector, or the parallel current collector. The embodiment of the present invention improves the magnetic field distribution around the magnetoresistive element through the parallel current collector structure, so that the magnetoresistive element can sense broadband currents above 1 MHz, and achieves the beneficial effects of simple structure and easy 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 transformation made by utilizing the contents of the present invention's description and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields, is included in the patent protection scope of the present invention.

Claims

1. A current sensor, characterized in that: Used to detect the current 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 first extension section of the first current collector and the second extension section of the second current collector extending in parallel; at least one magnetoresistive element, located above the first extension section and / or the second extension section, for collecting 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; The first current collector and the second current collector are flat conductive materials.

2. The current sensor according to claim 1, wherein 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 magnetically sensitive direction, and the second magnetoresistive arm and the fourth magnetoresistive arm have a second magnetically sensitive direction opposite to the first magnetically 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; and 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 magnetoresistive block includes the first magnetoresistive arm, the 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 pin via the first pad, and is electrically coupled 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 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, wherein The -3dB bandwidth of the current sensor is higher than 1 MHz.

5. The current sensor according to claim 1, wherein The distance between the first extension section and the second extension section is 24 to 48 mils.

6. The current sensor according to claim 1, wherein: 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 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; 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 further includes a control module electrically coupled to the first magnetoresistive element and the second magnetoresistive element, respectively, for determining the current condition of the conductor to be measured based on the sum of the output signals of the first magnetoresistive element and the second magnetoresistive element.

9. An electronic device, characterized in that: The electronic device comprises the current sensor according to any one of claims 1 to 8.

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