A magnetic isolator

Abstract

The present invention discloses a magnetic isolator, comprising a substrate, a magnetic field generating unit, a magnetic field sensing unit, a shielding layer, and an isolation medium. The magnetic field generating unit comprises a current conductor, the current conductor is extended along a first direction on one side of the substrate, the magnetic field sensing unit and the current conductor are arranged on the same side of the substrate, the magnetic field sensing unit is located on the side of the current conductor, and along the second direction, the distance between the current conductor and the magnetic field sensing unit is greater than 0, wherein the first direction is perpendicular to the second direction; an isolation medium is arranged between the current conductor and the magnetic field sensing unit; the isolation medium is arranged within the distance between the current conductor and the magnetic field sensing unit in the second direction, which can play a role of electrical isolation, is conducive to improving the isolation strength, and has a simple process. The shielding layer can absorb external interference magnetic fields and further improve the signal-to-noise ratio.

Description

Technical Field

[0001] The invention relates to the field of magnetic sensors, and in particular to a magnetic isolator. Background Art

[0002] In electronic circuits, various signals are prone to mutual interference. To ensure signal stability, signal isolators are often used. Currently, commercial signal isolators include optocouplers, capacitive coupling isolators, and magnetic isolators. Magnetic isolators have the characteristics of fast response frequency and easy integration, and are currently widely used.

[0003] The iCoupler series products successfully commercialized by ADI use chip-level transformer technology to integrate the primary and secondary coils on the semiconductor substrate. Between the primary and secondary, polyimide with high breakdown strength has an isolation voltage of up to 5000VRMS / min and a transmission rate of 150Mbps. Since the transformer only responds to high-frequency signals, if the input signal is a low-frequency signal, the original signal needs to be processed by chopping or other methods to achieve signal transmission between the primary and secondary.

[0004] NVE has developed the IsoLoop series of products using giant magnetoresistance (GMR) elements, with an isolation voltage of up to 6000V and a transmission rate of 150Mbps. This series of products has a primary coil inside, and a GMR element below the primary coil. The primary coil generates a horizontal magnetic field at the position of the GMR element, and the GMR element detects the horizontal magnetic field and outputs it, achieving isolated signal transmission. Between the primary coil and the GMR element, there is a 10μm thick benzocyclobutene (BCB) to achieve an isolation voltage of several thousand volts. Since the frequency response of the GMR element is from 0Hz to several MHz, it solves the problem that the transformer can only transmit high-frequency signals.

[0005] The high isolation voltage of the above two methods is achieved through the isolation layer between the signal transmitting element and the receiving element. In order to achieve high isolation voltage, high isolation voltage materials and thicker isolation layers are required. If silicon oxide or aluminum oxide is used as the isolation layer, it takes a long time to coat the film and requires a higher cost; if polymer materials such as polyimide or BCB are used as the isolation layer, there is a risk of device failure in certain extreme environments, such as moisture or high temperature environments. Summary of the invention

[0006] In view of the above technical problems, the present invention proposes a magnetic isolator, which includes a substrate, a magnetic field generating unit, a magnetic field sensing unit, a shielding layer, and an isolation medium. The magnetic field generating unit includes a current conductor, and the current conductor is extended along a first direction on one side of the substrate. The magnetic field sensing unit is located on the side of the current conductor; along the second direction, the distance between the current conductor and the magnetic field sensing unit is greater than 0, wherein the first direction is perpendicular to the second direction. There is an isolation medium between the current conductor and the magnetic field sensing unit, and the isolation medium can be an isolation material with high insulation strength. The isolation distance is only related to the horizontal distance between the current conductor and the magnetic field sensing unit. There are magnetic concentrators on the upper and lower sides of the magnetic field sensing unit, which can improve the output signal of the magnetic field sensing unit. There is a shielding layer on the upper and / or lower sides of the magnetic field sensing unit and the current conductor to absorb external interference magnetic fields and prevent the leakage of the magnetic field generated by the current conductor. The magnetic isolator has a simple structure, and the preparation process is relatively simplified, which saves costs.

[0007] The present invention is achieved according to the following technical solutions:

[0008] A magnetic isolator includes a substrate, a magnetic field generating unit, a magnetic field sensing unit, a shielding layer, and an isolation medium.

[0009] The magnetic field generating unit comprises a current conductor, the current conductor is extended along a first direction on one side of the substrate, the magnetic field sensing unit and the current conductor are arranged on the same side of the substrate, the magnetic field sensing unit is located on the side of the current conductor, and along a second direction, the distance between the current conductor and the magnetic field sensing unit is greater than 0, wherein the first direction is perpendicular to the second direction;

[0010] An isolation medium is provided between the current conductor and the magnetic field sensing unit; the current signal includes an input end, the current signal inputted at the input end flows through the current conductor to generate a magnetic field around the current conductor, and the magnetic field has a component in the sensitive direction of the magnetic field sensing unit, and the output signal sensed by the magnetic field sensing unit is proportional to the magnetic field generated around the current conductor;

[0011] The shielding layer and the magnetic field generating unit are located on the same side of the substrate, and on the side of the magnetic field generating unit close to the substrate and / or on the side away from the substrate, and are used to absorb external interference magnetic fields and prevent the magnetic field generated around the current conductor of the magnetic field generating unit from leaking.

[0012] Preferably, the magnetic field generating unit further comprises a voltage conversion unit, which is electrically connected to the input end of the current conductor and is used for converting an input voltage signal into a current signal.

[0013] Preferably, it further comprises a signal processing unit, which is electrically connected to the magnetic field sensing unit and is used to receive and process the output signal of the magnetic field sensing unit and output the processed signal.

[0014] Preferably, the signal processing unit comprises a filtering module, an amplifying module, a comparing module and a level converting module which are sequentially connected in series, wherein the filtering module is electrically connected to the magnetic field sensing unit.

[0015] Preferably, the magnetic field sensing unit is composed of a giant magnetoresistive element, wherein the magnetization direction of the pinned layer of the giant magnetoresistive element is perpendicular to the surface of the giant magnetoresistive element, and the sensitive direction of the giant magnetoresistive element is perpendicular to the surface of the giant magnetoresistive element; or

[0016] The pinning layer of the giant magnetoresistive element is parallel to the surface of the giant magnetoresistive element, and the sensitive direction of the giant magnetoresistive element is parallel to the surface of the giant magnetoresistive element.

[0017] Preferably, the magnetic field sensing unit is composed of a tunnel magnetoresistive element, wherein the magnetization direction of the pinned layer of the tunnel magnetoresistive element is perpendicular to the surface of the tunnel magnetoresistive element, and the sensitive direction of the tunnel magnetoresistive element is perpendicular to the surface of the tunnel magnetoresistive element; or

[0018] The pinning layer of the tunnel magnetoresistive element is parallel to the surface of the tunnel magnetoresistive element, and the sensitive direction of the tunnel magnetoresistive element is parallel to the surface of the tunnel magnetoresistive element.

[0019] Preferably, the magnetic field sensing unit is composed of a Hall element or an anisotropic magnetoresistive element.

[0020] Preferably, it also includes a magnetic concentrating sheet, which is arranged on the first side and the second side of the magnetic field sensing unit, wherein the first side and the second side are opposite sides of the magnetic field sensing unit, and the connection direction from the first side to the second side is the same as or opposite to the sensitive direction of the magnetic field sensing unit, and the magnetic concentrating sheet is used to enhance the magnetic field signal generated by the current conductor and the signal-to-noise ratio of the magnetic isolator.

[0021] Preferably, the material of the magnetic concentrating sheet and the shielding layer includes at least one of Permalloy, industrial pure iron and ferrite.

[0022] Preferably, the substrate is a silicon substrate, a quartz substrate or a glass substrate.

[0023] The isolation medium includes at least one of aluminum oxide, silicon oxide, silicon nitride, polyimide, and benzocyclobutene.

[0024] Compared with the prior art, the present invention has the following beneficial technical effects:

[0025] The magnetic isolator provided by the present invention can play the role of electrical isolation by arranging an isolation medium in the second direction (for a horizontally placed magnetic isolator, the horizontal direction) between the current conductor and the magnetic field sensing unit, which is beneficial to improving the isolation strength and has a simple process. The shielding layer can absorb the external interference magnetic field and further improve the signal-to-noise ratio. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0027] Figure 1 It is a cross-sectional schematic diagram of a conventional magnetic isolator in the prior art;

[0028] Figure 2 is a schematic diagram of the three-dimensional structure of a magnetic isolator provided by an embodiment of the present invention;

[0029] Figure 3 is a cross-sectional view of a magnetic isolator proposed by the present invention;

[0030] Figure 4 A schematic cross-sectional view of another magnetic isolator proposed by the present invention;

[0031] Figure 5 is a schematic diagram of the three-dimensional structure of another magnetic isolator provided in an embodiment of the present invention;

[0032] Figure 6 is a schematic diagram of the three-dimensional structure of another magnetic isolator provided in an embodiment of the present invention;

[0033] Figure 7 is a schematic diagram of an output curve of a magnetic field sensing unit provided by an embodiment of the present invention;

[0034] Figure 8 is a circuit diagram of a magnetic field sensing unit of a bridge structure provided by an embodiment of the present invention;

[0035] Fig. 9 is a circuit diagram of another bridge-structured magnetic field sensing unit provided by an embodiment of the present invention;

[0036] Fig.10 This is a schematic diagram of the position relationship between the current conductor and the magnetic field sensing unit provided in an embodiment of the present invention;

[0037] Fig.11 is another schematic diagram of the positional relationship between the current conductor and the magnetic field sensing unit provided in an embodiment of the present invention;

[0038] Fig.12 is another schematic diagram of the positional relationship between the current conductor and the magnetic field sensing unit provided in an embodiment of the present invention;

[0039] Fig.13 1 is a schematic diagram of the electrical structure of a magnetic isolator with resistance value output provided by an embodiment of the present invention;

[0040] Fig.14 1 is a schematic diagram of the electrical structure of a magnetic isolator with bridge voltage output provided by an embodiment of the present invention;

[0041] Fig.15 It is a schematic diagram of the electrical structure of a magnetic isolator with signal processing provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0042] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several changes and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0043] Figure 1 It is a cross-sectional schematic diagram of a conventional magnetic isolator in the prior art. All components are deposited on a substrate 101 through a semiconductor process or a MEMS process. A current signal is passed through the current conductor 102. The following description is based on the direction of the current signal being perpendicular to the paper surface and inward. The magnitude of the current signal is related to the magnitude of the measured current. There is a magnetic field sensing unit 104 directly below the current conductor 102. At the position of the magnetic field sensing unit 104, the direction of the magnetic field generated by the current conductor 102 is shown by the arrow 103 in the figure. The magnetic field sensing unit 104 senses the magnetic field and outputs it in the form of voltage. There is an isolation medium 105 between the current conductor 102 and the magnetic field sensing unit 104. The material and thickness of the isolation medium determine the isolation voltage. In order to enhance the suppression of the external field and reduce the leakage of the magnetic field, a shielding layer 106 is provided on the upper and lower sides of the current conductor 102 and the magnetic field sensing unit 104. In order to achieve a higher isolation voltage, a thicker isolation medium is usually required. If silicon oxide or aluminum oxide is used as the isolation layer, a longer coating time is required and a higher cost is required; if polymer materials such as polyimide or BCB are used as the isolation layer, there is a risk of device failure in certain extreme environments, such as moisture or high temperature environments.

[0044] Based on the above problems, an embodiment of the present invention proposes a magnetic isolator. Figure 2 is a schematic diagram of a three-dimensional structure of a magnetic isolator provided by an embodiment of the present invention, Figure 3 is a cross-sectional view of a magnetic isolator proposed by the present invention, and the section line corresponding to the cross section is A-A'. Figure 2 and Figure 3The magnetic isolator comprises a substrate 201, a magnetic field generating unit, a magnetic field sensing unit 203, a shielding layer 209, and an isolation medium. The magnetic field generating unit comprises a current conductor 202, the current conductor 202 is extended along a first direction x on one side of the substrate 201, the magnetic field sensing unit 203 and the current conductor 202 are arranged on the same side of the substrate 201, the magnetic field sensing unit 203 is located on the side of the current conductor 202, and along the second direction y, the distance between the current conductor 202 and the magnetic field sensing unit 203 is greater than 0, wherein the first direction x is perpendicular to the second direction y; an isolation medium is arranged between the current conductor 202 and the magnetic field sensing unit 203; the current conductor comprises an input end, the current signal input at the input end flows through the current conductor 202 to generate a magnetic field around the current conductor 202, and the magnetic field has a component in the sensitive direction of the magnetic field sensing unit 203, and the output signal sensed by the magnetic field sensing unit 203 is proportional to the magnetic field generated around the current conductor 202;

[0045] The shielding layer 209 and the magnetic field generating unit 203 are located on the same side of the substrate 201 , on the side of the magnetic field generating unit close to the substrate 201 and / or on the side away from the substrate 201 , and are used to absorb external interference magnetic fields and prevent the magnetic field generated around the current conductor 202 from leaking.

[0046] The isolation voltage between the current conductor 202 and the magnetic field sensing unit 203 is proportional to the spacing distance between the current conductor 202 and the magnetic field sensing unit 203 , and the spacing distance refers to the length of the connection between the current conductor 202 and the magnetic field sensing unit 203 .

[0047] refer to Figure 2 and Figure 3 Specifically, a current conductor 202 is provided on one side of the substrate 201, and an isolation medium may be provided between the current conductor 202 and the shielding layer 209. Magnetic field sensing units 203 and 205 are provided on the side of the current conductor 202. At the positions of the two magnetic field sensing units, the directions of the magnetic field generated by the current signal are arrows 204 and 206 in the figure, respectively, and the directions of the two arrows are also the sensitive directions of the magnetic field sensing units 203 and 205. For a certain current value, the output signals of the magnetic field sensing units 203 and 205 are different, and the isolated output of the signal can be achieved.

[0048] The spacing distance between the current conductor 202 and the magnetic field sensing unit 203 along the second direction is a1, and the spacing distance between the current conductor 202 and the magnetic field sensing unit 205 is a2, wherein a1 and a2 are greater than 0, and the isolation voltage is related to the length of the spacing distance. By increasing the length of the spacing, the isolation voltage can be increased, which is very easy to achieve in the process. In addition, in order to enhance the suppression of the external field and reduce the leakage of the magnetic field, the side of the current conductor 202, the magnetic field sensing unit 203 and 205 close to the substrate 201 and / or the side away from the substrate 201, that is, Figure 3 There are shielding layers 209 on the upper and lower sides.

[0049] Continue to refer Figure 2 and Figure 3 On the basis of the above scheme, the magnetic isolator further includes a magnetic concentrator 207, which is arranged on the first side and the second side of the magnetic field sensing unit, wherein the first side and the second side are opposite sides of the magnetic field sensing unit, and the connection direction from the first side to the second side is the same as or opposite to the sensitive direction of the magnetic field sensing unit, and the magnetic concentrator 207 is used to enhance the magnetic field signal of the magnetic field sensing unit and the signal-to-noise ratio of the magnetic isolator.

[0050] For example, Figure 3 For a horizontally placed magnetic isolator, the first side of the magnetic field sensing unit can be the upper side of the magnetic field sensing unit, and the second side can be the lower side of the magnetic field sensing unit; or the first side of the magnetic field sensing unit can be the lower side of the magnetic field sensing unit, and the second side can be the upper side of the magnetic field sensing unit. A magnetic concentrating sheet 207 is provided on the first side and the second side of the magnetic field sensing unit to increase the magnetic field strength at the magnetic field sensing unit and make the magnetic field direction along the sensitive direction of the magnetic field sensing unit.

[0051] The magnetic isolator provided by the embodiment of the present invention includes a substrate, a magnetic field generating unit, a magnetic field sensing unit, a shielding layer, and an isolation medium. The magnetic field generating unit includes a current conductor, and the current conductor is extended along a first direction on one side of the substrate. The magnetic field sensing unit and the current conductor are arranged on the same side of the substrate. The magnetic field sensing unit is located on the side of the current conductor, and along the second direction, the distance between the current conductor and the magnetic field sensing unit is greater than 0, wherein the first direction is perpendicular to the second direction; an isolation medium is arranged between the current conductor and the magnetic field sensing unit, and the isolation medium is arranged within the distance between the current conductor and the magnetic field sensing unit in the second direction, which can play a role of electrical isolation, is conducive to improving the isolation strength, and has a simple process. The shielding layer can absorb external interference magnetic fields and further improve the signal-to-noise ratio.

[0052] Based on the above scheme, the materials of the magnetic concentrator and the shielding layer include at least one of Permalloy, industrial pure iron, and ferrite. The substrate is a silicon substrate, a quartz substrate, or a glass substrate. The isolation medium includes at least one of aluminum oxide, silicon oxide, silicon nitride, polyimide, and benzocyclobutene.

[0053] Figure 4 This is another cross-sectional schematic diagram of a magnetic isolator proposed by the present invention. Under certain process conditions, the current conductor 302 will deviate from the center line of the magnetic field sensing units 303 and 305 in the height direction. The current direction in the current conductor 302 is perpendicular to the paper plane and inward. At this time, there are horizontal components on the magnetic field sensing units 303 and 305, as shown by arrows 304 and 306 in the figure. In this design, the sensitive direction of the magnetic field sensing units 303 and 305 is the horizontal direction (taking the magnetic isolator placed horizontally as an example). On the upper and lower sides of the magnetic field sensing units 303 and 305, magnetic concentrators 307 can be added to increase the magnetic field strength at the magnetic field sensing units and improve the signal output.

[0054] Figure 5 is a schematic diagram of the three-dimensional structure of another magnetic isolator provided in an embodiment of the present invention; Figure 6 It is a schematic diagram of the three-dimensional structure of another magnetic isolator provided in an embodiment of the present invention.

[0055] exist Figure 5 In the figure, 401 is a substrate, a magnetic field sensing unit is located on the side of a current conductor 402, and the magnetic field sensing unit is an M*N array composed of a plurality of magnetic sensing elements 403, wherein M and N are integers greater than or equal to 1, and an isolation medium is provided in the interval between the current conductor 402 and the magnetic sensing element 403, thus forming a magnetic isolator. In addition, in order to reduce the interference of the external magnetic field and reduce the leakage of the magnetic field, a shielding layer 405 with high magnetic permeability is provided above the magnetic field sensing unit and the current conductor 402.

[0056] Figure 6 Magnetic isolators and Figure 5 Compared with the above, the shielding layer 505 having two layers of high magnetic permeability can better play a shielding role.

[0057] Figure 7 : is a schematic diagram of the input and output curve of the magnetic field sensing unit provided by an embodiment of the present invention, in which the horizontal axis is the magnetic field signal, which is generated by the current around the current conductor, and the vertical axis is the output voltage of the full-bridge structure magnetic field sensing unit. The magnetic field sensing unit has a saturation magnetic field B1, and as long as the absolute value of the magnetic field is less than the saturation magnetic field B1, the output voltage of the magnetic field sensing unit is proportional to the magnetic field signal, and the magnetic field signal is proportional to the current signal. Therefore, the output voltage of the magnetic field sensing unit is proportional to the current signal.

[0058] Figure 8 801 to 804 represent four magnetic induction resistors, each of which is composed of a number of magnetic induction elements. The solid arrows are the sensitive directions of the four magnetic induction resistors, and the dotted arrows are the magnetic field directions of the four magnetic induction resistors. Since the sensitive directions of the four magnetic induction resistors are opposite to each other, when a magnetic field is applied to the four magnetic induction resistors, a differential output signal is formed, and the following can be obtained: Figure 7 The output curve is shown.

[0059] Fig. 9 1 is a schematic diagram of another magnetic field sensing unit of a bridge structure provided by an embodiment of the present invention. The four magnetic induction resistors 901 to 904 have the same sensitive direction. Through layout design, the magnetic fields at the positions of the four magnetic induction resistors can be made opposite to each other. Figure 7 The output curve is shown in Figure 2. Since the sensitive directions are the same, this bridge structure can reduce the interference of external common-mode magnetic fields.

[0060] It should be noted that the shape of the current conductor may be a long strip, a spiral coil, or other shapes, and the present invention does not make any specific limitation here. Figure 10 to Figure 12 This is a diagram showing the positional relationship between three typical current conductors and magnetic field sensing units.

[0061] Fig.10 is a schematic diagram of the position relationship between the current conductor and the magnetic field sensing unit provided in an embodiment of the present invention, with reference to Fig.10 , Fig.10 The dotted box 1004 in the figure represents the location of the magnetic field sensing unit. The current conductor 1001 has two ports 1002 and 1003. When current flows through the current conductor 1001, there is a magnetic field in the dotted box 1004 with the same direction, equal magnetic field magnitude, and the same magnetic field direction. If four magnetic induction resistors are placed in the dotted box, and each magnetic induction resistor has a sensitive direction opposite to that of the adjacent magnetic induction resistor, the following can be formed: Figure 8 It should be noted that when the current conductor is in the shape of a coil, the two ports 1002 and 1003 of the coil serve as the input end and the output end of the current conductor respectively, the magnetic induction unit is on the side of the current conductor, and in the second direction, the magnetic field induction unit satisfies that the distance from the input end or the output end of the current conductor is greater than 0.

[0062] Fig.11 is another schematic diagram of the position relationship between the current conductor and the magnetic field sensing unit provided in an embodiment of the present invention, with reference to Fig.11, the current conductor 1101 also has two ports 1102 and 1103. When current flows through the current conductor 1101, the magnetic fields in the dashed boxes 1103 and 1104 are equal in magnitude and opposite in direction. If magnetic induction resistors with the same sensitivity are placed in the dashed boxes 1103 and 1104, the number of magnetic induction resistors can be determined according to actual needs, and the following can be constructed: Fig. 9 The bridge structure shown.

[0063] Fig.12 is another schematic diagram of the position relationship between the current conductor and the magnetic field sensing unit provided in an embodiment of the present invention, with reference to Fig.12 , Fig.12 There are several dotted boxes in the figure. The current conductor 1201 also has two ports 1202 and 1203. When current flows through the current conductor 1201, the magnetic fields in the dotted boxes 1204 and 1205 are equal in magnitude and opposite in direction. If magnetic induction resistors with the same sensitivity are placed in the dotted boxes 1204 and 1205, the following can be formed: Fig. 9 The bridge structure shown.

[0064] Figure 13 to Figure 15 There are three types of magnetic isolators with output.

[0065] Fig.13 1 is a schematic diagram of the electrical structure of a magnetic isolator with resistance value output provided by an embodiment of the present invention; Fig.13 It is a magnetic isolator in the form of resistance output. In the figure, 1301 and 1302 are the signal input terminals of the isolator. The magnetic field generating unit 1303 has a current conductor. When there is an input signal, the current conductor generates a magnetic field. The magnetic field sensing unit 1304 (a resistor array composed of Hall, AMR, GMR or TMR resistors) senses the magnetic field and changes the resistance value. The resistance value is output through output ports 1305 and 1306.

[0066] According to a specific embodiment of the present invention, when the magnetic field sensing unit is composed of a giant magnetoresistance (GMR) element, wherein the magnetization direction of the pinned layer of the GMR element is perpendicular to the surface of the GMR element, and the sensitive direction of the GMR element is perpendicular to the surface of the GMR element; or

[0067] The pinning layer of the GMR element is parallel to the surface of the GMR element, and the sensitive direction of the GMR element is parallel to the surface of the TMR or GMR element.

[0068] According to another specific embodiment of the present invention, when the magnetic field sensing unit is composed of a tunnel magnetoresistance (TMR) element, wherein the magnetization direction of the pinned layer of the TMR element is perpendicular to the surface of the TMR element, and the sensitive direction of the TMR element is perpendicular to the surface of the TMR element; or

[0069] The pinning layer of the TMR element is parallel to the surface of the TMR element, and the sensitive direction of the TMR element is parallel to the surface of the TMR element.

[0070] According to another embodiment of the present invention, the magnetic field sensing unit is composed of a Hall element or an anisotropic magnetoresistive element.

[0071] Fig.14 1401 and 1402 are signal input terminals of the isolator, and a magnetic field generating unit 1403 has a current conductor, and when there is an input signal, the current conductor generates a magnetic field. The magnetic field sensing unit 1404 has a half-bridge circuit structure or a full-bridge circuit structure, and outputs a voltage signal, wherein ports 1405 and 1406 are power supply terminals of the magnetic field sensing unit, and ports 1407 and 1408 are voltage output terminals of the magnetic field sensing unit.

[0072] Optionally, the magnetic isolator further includes a signal processing unit, which is electrically connected to the magnetic field sensing unit and is used to receive and process the output signal of the magnetic field sensing unit and output the processed signal. The signal processing unit includes a filter module, an amplification module, a comparison module and a level conversion module connected in series in sequence, wherein the filter module is electrically connected to the magnetic field sensing unit. Fig.15 1 is a schematic diagram of the electrical structure of a magnetic isolator with signal processing provided in an embodiment of the present invention. In the figure, 1501 and 1502 are signal input terminals of the isolator, and voltage or current signals are input to the signal input terminals. A current conductor is provided in the magnetic field generating unit 1503. When there is an input signal, the current conductor generates a magnetic field. The magnetic field sensing unit 1504 has a half-bridge circuit structure or a full-bridge circuit structure, and outputs a voltage signal. The signal processing unit 1507 receives the output signal of the magnetic field sensing unit 1504, processes the output signal of the magnetic field sensing unit 1504, and outputs it from ports 1508 and 1509. Ports 1505 and 1506 are power supply terminals for the magnetic field generating unit and the signal processing unit.

[0073] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Although the present invention is illustrated and described with respect to the preferred embodiments, it should be understood by those skilled in the art that various changes and modifications can be made to the present invention as long as they do not exceed the scope defined by the claims of the present invention.

Claims

1. A magnetic isolator, characterized in that: It includes a substrate, a magnetic field generating unit, a magnetic field sensing unit, a shielding layer, and an isolation medium. The magnetic field generating unit comprises a current conductor, the current conductor is extended along a first direction on one side of the substrate, the magnetic field sensing unit and the current conductor are arranged on the same side of the substrate, along a second direction, the magnetic field sensing unit is located on both sides of the current conductor, and along the second direction, the distance between the current conductor and the magnetic field sensing unit is greater than 0, and the isolation voltage between the current conductor and the magnetic field sensing unit is proportional to the distance between the current conductor and the magnetic field sensing unit, wherein the first direction is perpendicular to the second direction; An isolation medium is provided between the current conductor and the magnetic field sensing unit; the current conductor comprises an input end, a current signal inputted at the input end flows through the current conductor to generate a magnetic field around the current conductor, and the magnetic field has a component in a sensitive direction of the magnetic field sensing unit, and an output signal sensed by the magnetic field sensing unit is proportional to the magnetic field generated around the current conductor; The shielding layer and the magnetic field generating unit are located on the same side of the substrate, and on a side of the magnetic field generating unit close to the substrate and / or a side away from the substrate, and is used to absorb external interference magnetic fields and prevent leakage of the magnetic field generated around the current conductor of the magnetic field generating unit; The magnetic field sensing unit is a bridge structure, and includes four magnetic induction resistors. Each of the magnetic induction resistors is composed of a plurality of magnetic induction elements. In the same magnetic field sensing unit, the sensitive directions of the magnetic induction resistors are the same.

2. The magnetic isolator according to claim 1, characterized in that: The magnetic field generating unit further comprises a voltage conversion unit, which is electrically connected to the input end of the current conductor and is used for converting an input voltage signal into a current signal.

3. The magnetic isolator according to claim 1 or 2, characterized in that: It also includes a signal processing unit, which is electrically connected to the magnetic field sensing unit and is used to receive and process the output signal of the magnetic field sensing unit and output the processed signal.

4. The magnetic isolator according to claim 3, characterized in that: The signal processing unit comprises a filtering module, an amplifying module, a comparing module and a level converting module which are sequentially connected in series, wherein the filtering module is electrically connected to the magnetic field sensing unit.

5. The magnetic isolator according to claim 1, characterized in that: The magnetic field sensing unit is composed of a giant magnetoresistive element, wherein the magnetization direction of the pinned layer of the giant magnetoresistive element is perpendicular to the surface of the giant magnetoresistive element, and the sensitive direction of the giant magnetoresistive element is perpendicular to the surface of the giant magnetoresistive element; or The pinning layer of the giant magnetoresistive element is parallel to the surface of the giant magnetoresistive element, and the sensitive direction of the giant magnetoresistive element is parallel to the surface of the giant magnetoresistive element.

6. The magnetic isolator according to claim 1, characterized in that: The magnetic field sensing unit is composed of a tunnel magnetoresistive element, wherein the magnetization direction of the pinned layer of the tunnel magnetoresistive element is perpendicular to the surface of the tunnel magnetoresistive element, and the sensitive direction of the tunnel magnetoresistive element is perpendicular to the surface of the tunnel magnetoresistive element; or The pinning layer of the tunnel magnetoresistive element is parallel to the surface of the tunnel magnetoresistive element, and the sensitive direction of the tunnel magnetoresistive element is parallel to the surface of the tunnel magnetoresistive element.

7. The magnetic isolator according to claim 1, characterized in that: The magnetic field sensing unit is composed of a Hall element or an anisotropic magnetoresistive element.

8. The magnetic isolator according to claim 1, characterized in that: It also includes a magnetic concentrating sheet, which is arranged on the first side and the second side of the magnetic field sensing unit, wherein the first side and the second side are two opposite sides of the magnetic field sensing unit, and the connection direction from the first side to the second side is the same as or opposite to the sensitive direction of the magnetic field sensing unit, and the magnetic concentrating sheet is used to enhance the magnetic field signal generated by the current conductor and the signal-to-noise ratio of the magnetic isolator.

9. A magnetic isolator according to claim 8, characterized in that: The materials of the magnetic concentrating sheet and the shielding layer include at least one of Permalloy, industrial pure iron and ferrite.

10. The magnetic isolator according to claim 1, characterized in that: The substrate is a silicon substrate, a quartz substrate or a glass substrate. The isolation medium includes at least one of aluminum oxide, silicon oxide, silicon nitride, polyimide, and benzocyclobutene.

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