A TMR full-bridge magnetic sensor and magnetic sensing device

Abstract

The application discloses a TMR full-bridge magnetic sensor and a magnetic sensing device, and is applied to the technical field of magnetic sensing. A single arm of an electric bridge comprises an initialization circuit and a plurality of series-connected array units, and the array unit comprises a plurality of MTJ component structures. The MTJ component structure comprises, from top to bottom, a top electrode, a tunnel junction, a spin-orbit moment providing line and two bottom electrodes located in the same layer. The reference layer in the tunnel junction is arranged close to the spin-orbit moment providing line. In the same array unit, a plurality of top electrodes are connected to each other, and a plurality of spin-orbit moment providing lines are connected through the bottom electrodes. The initialization circuit is connected to the bottom electrode. A separate spin-orbit moment providing line is arranged for each MTJ component structure, so that the MTJ component structure can form a single arm of an electric bridge in a series-parallel manner, and the full-bridge output resistance and power consumption size are convenient to adjust. The magnetic moment writing mode is simple, and a complex structure is not needed to form a Wheatstone full-bridge structure.

Description

Technical Field

[0001] This invention relates to the field of magnetic sensing technology, and in particular to a TMR full-bridge magnetic sensor and a magnetic sensing device. Background Technology

[0002] Magnetic tunneling junctions (MTJs) are a new type of magnetoresistive sensor that has begun to be used in industry in recent years. This type of sensor utilizes the tunneling magnetoresistance (TMR) effect of a magnetic multilayer film to detect external magnetic fields. This is mainly manifested in the fact that the resistance of the magnetic multilayer film in the TMR sensor changes with the angle and magnitude of the external magnetic field. Compared to the widely used Hall and AMR (Anisotropic Magnetoresistance) sensors, TMR sensors have advantages such as high sensitivity, high resistivity, low power consumption, and high resolution.

[0003] Compared to single-resistor and half-bridge sensors, Wheatstone's full-bridge magnetoresistive sensors offer higher sensitivity and better temperature compensation, suppressing temperature-induced output signal drift.

[0004] However, in existing technologies, monolithically integrated Wheatstone full-bridge magnetoresistive sensors have relatively complex structures and are difficult to manufacture, mainly due to the complexity of magnetizing the pinned layers. Therefore, providing a TMR full-bridge magnetic sensor with a simple structure and initialization method is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] The purpose of this invention is to provide a TMR full-bridge magnetic sensor that can be monolithically integrated and has a simple, low-cost, and high-efficiency method for initializing the magnetization direction of the pinned layer. Another purpose of this invention is to provide a magnetic sensing device with a simple, low-cost, and high-efficiency method for initializing the magnetization direction of the pinned layer.

[0006] To address the aforementioned technical problems, this invention provides a TMR full-bridge magnetic sensor, comprising four bridge arms forming a Wheatstone full-bridge; each bridge arm includes an initialization circuit and multiple array units connected in series, the array units comprising multiple MTJ component structures;

[0007] The MTJ component structure includes, from top to bottom, a top electrode, a tunnel junction, a spin orbital moment providing line, and two bottom electrodes located on the same layer; the reference layer in the tunnel junction is located close to the spin orbital moment providing line, one end of the spin orbital moment providing line is connected to one of the bottom electrodes, and the other end is connected to the other bottom electrode; multiple top electrodes are interconnected in the same array unit, and multiple spin orbital moment providing lines are connected through the bottom electrodes, so that multiple tunnel junctions in the same array unit are connected in parallel;

[0008] The initialization circuit is connected to the bottom electrode to control the writing of the magnetic moment of the reference layer. The magnetic moment directions of each reference layer in the same single arm of the bridge are the same, while the magnetic moment directions of the reference layers in adjacent single arms of the bridge are opposite.

[0009] Optionally, adjacent array units in the same single arm of the bridge can be connected in series via adjacent top or bottom electrodes.

[0010] Optionally, adjacent array units in the same single arm of the bridge are alternately connected in series via the connected top electrode and the bottom electrode;

[0011] Two array units connected in series with their bottom electrodes form a write circuit unit. The bottom electrodes at both ends of the write circuit unit are connected to the control switch of the initialization circuit. The control switch includes a write transistor and a write word line connected to the gate of the transistor. One of the two write transistors is connected to the write signal input terminal, and the other write transistor is grounded.

[0012] Optionally, the Wheatstone full bridge is connected to a ground terminal, a differential output terminal, a working signal input terminal, a write line control terminal, and the write signal input terminal; the write line control terminal is connected to the write line.

[0013] Optionally, it also includes a first transistor and a second transistor, the gates of the first transistor and the second transistor are both connected to the write line control terminal, the working signal input terminal is connected to the input pad through the first transistor, and the write signal input terminal is connected to the input pad through the second transistor.

[0014] Optionally, the first transistor is a PMOS transistor and the second transistor is an NMOS transistor.

[0015] Optionally, the grounding terminal, the differential output terminal, and the working signal input terminal are all connected to the top electrode.

[0016] Optionally, the array units are arranged in parallel.

[0017] Optionally, the number of MTJ component structures in the array unit is equal.

[0018] The present invention also provides a magnetic sensing device, including a TMR full-bridge magnetic sensor as described in any of the preceding claims.

[0019] The present invention provides a TMR full-bridge magnetic sensor comprising four bridge arms forming a Wheatstone full-bridge; each bridge arm includes an initialization circuit and multiple array units connected in series, each array unit including multiple MTJ component structures; each MTJ component structure includes, from top to bottom, a top electrode, a tunnel junction, a spin-orbit moment providing line, and two bottom electrodes located on the same layer; a reference layer in the tunnel junction is positioned close to the spin-orbit moment providing line, one end of the spin-orbit moment providing line is connected to one bottom electrode, and the other end is connected to the other bottom electrode; multiple top electrodes are interconnected in the same array unit, and multiple spin-orbit moment providing lines are connected through bottom electrodes, so that multiple tunnel junctions in the same array unit are connected in parallel; the initialization circuit is connected to the bottom electrodes to control the writing of the magnetic moment of the reference layer, the magnetic moment directions of each reference layer in the same bridge arm are the same, and the magnetic moment directions of the reference layers in adjacent bridge arms are opposite.

[0020] Each MTJ component structure is equipped with a separate spin orbital moment supply line, allowing the MTJ component structures to form a single arm of a bridge through series and parallel connections. This facilitates adjustment of the full-bridge output resistance and power consumption by changing the number of MTJ component structures connected in series and parallel. When writing the magnetic moment direction of the array unit, under the same applied bias magnetic field, controlling the direction of the current through the spin orbital moment supply line allows for writing magnetic moments in different directions to different reference layers, forming a Wheatstone full-bridge structure. This magnetic moment writing method is simple and does not require the deposition of multilayer films or the use of multi-chip packaging technology to form a Wheatstone full-bridge structure, ensuring the simplicity of the TMR full-bridge magnetic sensor structure.

[0021] This application also provides a magnetic sensing device, which has the same beneficial effects as described above, and will not be described in detail here. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of 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 these drawings without creative effort.

[0023] Figure 1 This is a cross-sectional schematic diagram of an MTJ component structure provided in an embodiment of the present invention;

[0024] Figure 2 A cross-sectional schematic diagram of an array unit provided in an embodiment of the present invention;

[0025] Figure 3 for Figure 2 The corresponding schematic diagram of the reference layer magnetic moment writing principle;

[0026] Figure 4 This is a cross-sectional schematic diagram of a single arm of a bridge provided in an embodiment of the present invention;

[0027] Figure 5 for Figure 4 The corresponding equivalent circuit diagram of a single arm of the bridge;

[0028] Figure 6 This is a schematic diagram of a single-arm bridge initialization circuit provided in an embodiment of the present invention;

[0029] Figure 7 for Figure 6 The corresponding single-arm initialization control schematic diagram of the bridge;

[0030] Figure 8 This is a schematic diagram of the structure of a TMR full-bridge magnetic sensor provided in an embodiment of the present invention;

[0031] Figure 9 for Figure 8 The corresponding TMR full-bridge magnetic sensor circuit diagram;

[0032] Figure 10 This is a schematic diagram of a write control circuit provided in an embodiment of the present invention.

[0033] In the diagram: 1. Top electrode, 2. Tunnel junction, 21. Free layer, 22. Barrier layer, 23. Reference layer, 3. Spin-orbit moment supply line, 4. Bottom electrode, 5. Array cell, 6. Write circuit cell, 7. First transistor, 8. Second transistor, 9. Input pad;

[0034] EWL. Write line, VEWL. Write line control terminal, V1, V2. Differential output terminals, Vbias. Working signal input terminal, Vwrite. Write signal input terminal, GND. Ground terminal. Detailed Implementation

[0035] The core of this invention is to provide a TMR full-bridge magnetic sensor. In existing technologies, since MTJs deposited on the same substrate typically have identical pinned layer magnetic moments, fabricating a full-bridge magnetic sensing structure on a single wafer presents a significant challenge. Current methods for fabricating full-bridge TMR magnetic sensors mainly include: First, using a double thin-film deposition process to reverse the magnetization directions of the pinned layers of adjacent bridge arm magnetoresistive units; this process is complex and suffers from poor consistency. Second, taking multiple magnetoresistive arrays from the same or different wafers, flipping them 180° by separating the cores, and using multi-chip packaging technology to form a bridge connection structure. This method has limited packaging size, and the detection accuracy and sensitivity are affected by the angle between the chips. Third, using laser local heating and applying a reverse magnetic field to locally flip the magnetic domains and reverse the magnetization directions of the pinned layers of adjacent bridge arm magnetoresistive units; this method requires specialized annealing equipment, which is expensive and time-consuming. Fourth, using a flux concentrator to change the direction of the external magnetic field, thereby causing the output trends of adjacent bridge arm magnetoresistive units to be opposite. This method requires a large distance between bridge arms, which increases the size of the device. Different flux concentrator shapes need to be designed for different applications, and the process is complicated.

[0036] The present invention provides a TMR full-bridge magnetic sensor comprising four bridge arms forming a Wheatstone full-bridge; each bridge arm includes an initialization circuit and multiple array units connected in series, each array unit including multiple MTJ component structures; each MTJ component structure includes, from top to bottom, a top electrode, a tunnel junction, a spin orbital moment providing line, and two bottom electrodes located on the same layer; a reference layer in the tunnel junction is positioned close to the spin orbital moment providing line, one end of the spin orbital moment providing line is connected to one bottom electrode, and the other end is connected to the other bottom electrode; multiple top electrodes are interconnected in the same array unit, and multiple spin orbital moment providing lines are connected through bottom electrodes, so that multiple tunnel junctions in the same array unit are connected in parallel; the initialization circuit is connected to the bottom electrodes to control the writing of the magnetic moment of the reference layer, the magnetic moment directions of each reference layer in the same bridge arm are the same, and the magnetic moment directions of the reference layers in adjacent bridge arms are opposite.

[0037] Each MTJ component structure is equipped with a separate spin orbital moment supply line, allowing the MTJ component structures to form a single arm of a bridge through series and parallel connections. This facilitates adjustment of the full-bridge output resistance and power consumption by changing the number of MTJ component structures connected in series and parallel. When writing the magnetic moment direction of the array unit, under the same applied bias magnetic field, controlling the direction of the current through the spin orbital moment supply line allows for writing magnetic moments in different directions to different reference layers, forming a Wheatstone full-bridge structure. This magnetic moment writing method is simple and does not require the deposition of multilayer films or the use of multi-chip packaging technology to form a Wheatstone full-bridge structure, ensuring the simplicity of the TMR full-bridge magnetic sensor structure.

[0038] To enable those skilled in the art to better understand the present invention, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] Example 1

[0040] Please refer to Figures 1 to 5 , Figure 1 This is a cross-sectional schematic diagram of an MTJ component structure provided in an embodiment of the present invention; Figure 2 A cross-sectional schematic diagram of an array unit provided in an embodiment of the present invention; Figure 3 for Figure 2 The corresponding schematic diagram of the reference layer magnetic moment writing principle; Figure 4 This is a cross-sectional schematic diagram of a single arm of a bridge provided in an embodiment of the present invention; Figure 5 for Figure 4 The corresponding equivalent circuit diagram of a single arm of a bridge.

[0041] In this embodiment of the invention, the TMR full-bridge magnetic sensor includes four bridge arms forming a Wheatstone full-bridge; each bridge arm includes an initialization circuit and multiple array units 5 connected in series, each array unit 5 including multiple MTJ component structures; each MTJ component structure includes a top electrode 1, a tunnel junction 2, a spin orbital moment providing line 3, and two bottom electrodes 4 located on the same layer, arranged sequentially from top to bottom; a reference layer 23 in the tunnel junction 2 is disposed close to the spin orbital moment providing line 3, one end of the spin orbital moment providing line 3 is connected to one of the bottom electrodes 4, and the other end is connected to the other bottom electrode 4; multiple top electrodes 1 are interconnected in the same array unit 5, and multiple spin orbital moment providing lines 3 are connected through the bottom electrodes 4, so that multiple tunnel junctions 2 in the same array unit 5 are connected in parallel; the initialization circuit is connected to the bottom electrodes 4 to control the magnetic moment writing of the reference layer 23, the magnetic moment directions of each reference layer 23 in the same bridge arm are the same, and the magnetic moment directions of the reference layers 23 in adjacent bridge arms are opposite.

[0042] See Figure 1The TMR full-bridge magnetic sensor provided in this embodiment is constructed using an MTJ component structure as the smallest structural unit. This MTJ component structure includes, from top to bottom, a top electrode 1, a tunnel junction 2, a spin-orbit moment providing line 3, and two bottom electrodes 4 located on the same layer. Clearly, the bottom electrodes 4 in the entire TMR full-bridge magnetic sensor are all located on the same layer. Other structures, such as the spin-orbit moment providing lines 3 of different MTJ component structures, are also located on the same layer; the various film layers in the tunnel junction 2 are located on their corresponding layers; film layers of the same type are located on the same layer; and the bottom electrodes 4 are also located on the same layer. This structure avoids multi-layered deposition of reference layers 23, resulting in a relatively simple overall structure for the full-bridge TMR magnetic sensor.

[0043] The aforementioned tunnel junction 2 includes a reference layer 23, a barrier layer 22, and a free layer 21 arranged sequentially from bottom to top along the thickness direction. The reference layer 23 needs to be positioned close to the spin orbital moment supply line 3 to facilitate the subsequent writing of magnetic moments into the reference layer 23. The specific structure of the tunnel junction 2 and the specific functions of each film layer can be found in existing technologies and will not be elaborated upon here. The aforementioned top electrode 1 is specifically located on the side of the free layer 21 facing away from the reference layer 23. The specific structure and material of the top electrode 1 can be determined according to actual conditions and are not specifically limited here.

[0044] The aforementioned spin-orbit torque providing line 3 is specifically located on the side of the reference layer 23 facing away from the top electrode 1. This spin-orbit torque providing line 3 mainly achieves the control of the magnetization direction based on the localized SOT (Spin-Orbit Torque) effect, that is, the direction of the magnetic moment of the reference layer 23 after magnetization is controlled by controlling the direction of the write current. For details on the SOT effect, please refer to the prior art. It should be noted that in this embodiment, each MTJ component structure corresponds to a segment of spin-orbit torque providing line 3, and the spin-orbit torque providing lines 3 of adjacent MTJ component structures are not directly connected but are connected through the bottom electrode 4. That is, in this embodiment, a segment of spin-orbit torque providing line 3 corresponds to only one tunnel junction 2.

[0045] In this embodiment, a bottom electrode 4 is disposed on the side of the spin orbital moment providing line 3 facing away from the top electrode 1. All bottom electrodes 4 are located on the same layer. One spin orbital moment providing line 3 is connected to two bottom electrodes 4. One bottom electrode 4 is electrically connected at one end of the spin orbital moment providing line 3, and the other bottom electrode 4 is electrically connected at the other end of the spin orbital moment providing line 3. In this embodiment, the connection of the spin orbital moment providing lines 3 relies on the interconnection of the bottom electrodes 4.

[0046] See Figure 2Multiple tunnel junctions 2 located in the same array unit 5 need to be connected in parallel. Therefore, the top electrodes 1 of each MTJ component structure in the same array unit 5 need to be connected to each other, while the spin orbital moment supply lines 3 of each MTJ component structure in the same array unit 5 need to be connected in series through the bottom electrodes 4, thereby realizing the parallel connection of multiple tunnel junctions 2 connected to them. Within the same single arm of the bridge, multiple array units 5 need to be connected in series.

[0047] In this embodiment, each bridge arm is also equipped with an initialization circuit. This initialization circuit needs to be electrically connected to each bottom electrode 4 to provide a current in a preset direction to the spin orbital moment supply line 3 through the bottom electrode 4, thereby writing a magnetic moment of a certain direction to the reference layer 23. In this embodiment, it is necessary to ensure that after writing the magnetic field, the magnetic moments of the reference layers 23 in the same bridge arm are in the same direction, while the magnetic moments of the reference layers 23 in adjacent bridge arms are in opposite directions, in order to form a Wheatstone full-bridge structure.

[0048] See Figure 3 Specifically, an external bias magnetic field Bex is required when writing the magnetic field. When the current through the spin orbital moment supply line 3 in a certain direction exceeds a threshold, the tunnel junctions 2 connected to it will be simultaneously written to the same state. Under certain material combinations, when the current through the spin orbital moment supply line 3 flows from left to right, the reference layers 23 of all tunnel junctions 2 can be written in the vertically upward direction in the first current direction. If a reverse current is applied, the reference layers 23 of all tunnel junctions 2 can be written in the vertically downward direction, achieving reverse magnetization of the reference layers 23.

[0049] See Figure 4 as well as Figure 5 Specifically, in this embodiment, adjacent array units 5 in the same bridge arm can be connected in series via adjacent top electrodes 1 or bottom electrodes 4. In this case, each array unit 5 in the bridge arm can initialize the reference layer 23 of all tunnel junctions 2 in the bridge arm to the same orientation by applying current or voltage to the spin orbital moment line 3. Since the array units 5 are connected in series by connecting the top electrodes 1 or bottom electrodes 4 between adjacent array units 5, no additional structure is needed in the bridge arm for series connection. For the final TMR full-bridge magnetic sensor, to facilitate circuit setup, the array units 5 are usually arranged in parallel, and the number of MTJ components in each array unit 5 is usually equal to ensure that the performance of each arm does not deviate significantly and to simplify the overall circuit.

[0050] This embodiment provides a TMR full-bridge magnetic sensor with a separate spin-orbit moment supply line 3 for each MTJ component structure. This allows the MTJ component structures to form a single arm of the bridge through series and parallel connections, facilitating the adjustment of the full-bridge output resistance and power consumption by changing the number of MTJ component structures connected in series and parallel. When writing the magnetic moment direction of the array unit 5, under the same applied bias magnetic field, controlling the direction of the current through the spin-orbit moment supply line 3 allows for writing magnetic moments in different directions to different reference layers 23, forming a Wheatstone full-bridge structure. This magnetic moment writing method is simple and does not require the deposition of multiple layers or the use of multi-chip packaging technology to form a Wheatstone full-bridge structure, ensuring the simplicity of the TMR full-bridge magnetic sensor structure.

[0051] The specific details of the TMR full-bridge magnetic sensor provided by this invention will be described in detail in the following embodiments.

[0052] Example 2

[0053] Please refer to Figures 6 to 10 , Figure 6 This is a schematic diagram of a single-arm bridge initialization circuit provided in an embodiment of the present invention; Figure 7 for Figure 6 The corresponding single-arm initialization control schematic diagram of the bridge;

[0054] Figure 8 This is a schematic diagram of the structure of a TMR full-bridge magnetic sensor provided in an embodiment of the present invention;

[0055] Figure 9 for Figure 8 The corresponding TMR full-bridge magnetic sensor circuit diagram; Figure 10 This is a schematic diagram of a write control circuit provided in an embodiment of the present invention.

[0056] Unlike the embodiments described above, the embodiments of the present invention further define the specific content of the initialization circuit based on the embodiments described above. The remaining details have been described in detail in the embodiments described above and will not be repeated here.

[0057] See Figure 6 In this embodiment of the invention, adjacent array units 5 in the same single arm of the bridge are alternately connected in series through the connected top electrode 1 and the bottom electrode 4; two array units 5 connected in series by the bottom electrode 4 form a write circuit unit 6, and the bottom electrodes 4 at both ends of the write circuit unit 6 are connected to the control switch of the initialization circuit. The control switch includes a write transistor and a write word line EWL connected to the gate of the transistor; one of the two write transistors is connected to the write signal input terminal Vwrite, and the other write transistor is grounded.

[0058] In this embodiment, a write circuit unit 6 needs to be set up, which is the smallest unit for writing magnetic moments to the TMR full-bridge magnetic sensor. In this embodiment, the two array units 5 connected in series by the bottom electrode 4 are considered as the write circuit unit 6. Therefore, the above-mentioned write circuit unit 6 needs to be formed in the same single arm of the bridge by alternately using the connected top electrode 1 and the connected bottom electrode 4 in series array units 5.

[0059] See Figure 7 In this embodiment, the bottom electrode 4 at both ends of the write circuit unit 6 needs to be connected to the control switch of the initialization circuit. The control switch includes a write transistor and a write word line EWL connected to the gate of the transistor. One of the two write transistors is connected to the write signal input terminal Vwrite, and the other write transistor is grounded. The write word line EWL can control the on / off state of the corresponding write transistor, thereby controlling the initialization signal to flow through the write transistor and the bottom electrode 4 to the spin orbit moment providing line 3 to write the magnetic moment of the reference layer 23. In this embodiment, each set of write circuit units 6 needs to be connected to the control switch of the above structure, and the ungrounded write transistor in each set of control switches needs to be connected to the write signal input terminal Vwrite. The external initialization signal will input an electrical signal to the spin orbit moment providing line 3 through the write signal input terminal Vwrite, and the write word line EWL needs to be connected to the write word line EWL control terminal VEWL. The external enable signal for controlling the write word line EWL needs to be input based on the write word line EWL control terminal VEWL, that is, the write word line EWL is controlled by the same enable signal.

[0060] See Figure 8 as well as Figure 9 In this embodiment, the Wheatstone full bridge is connected to a ground terminal GND, differential output terminals V1 and V2, a working signal input terminal Vbias, a write word line EWL control terminal VEWL, and a write signal input terminal Vwrite; the write word line EWL control terminal VEWL is connected to the write word line EWL. The aforementioned four ports—GND, V1 and V2, and Vbias (the differential output terminals include two ports)—are the standard four ports of a Wheatstone full bridge. However, in this embodiment, to facilitate the initialization of the magnetic moments of each reference layer 23, two additional ports—the write word line EWL control terminal VEWL and the write signal input terminal Vwrite—are provided on the Wheatstone full bridge. The write signal input terminal Vwrite is used to input an initialization signal to provide power to the spin orbital moment line 3, and the write word line EWL control terminal VEWL is used to input an enable signal to control the on / off state of the write transistor, thereby completing the initialization of each reference layer 23.

[0061] Specifically, the working signal input terminal Vbias controls the input voltage of the full bridge, the differential output terminals V1 and V2 are the differential outputs of the full bridge, the write signal input terminal Vwrite controls the write voltage, and the spin orbit moment provides current to line 3 in the direction of the arrow shown by the dashed line, resetting or initializing the reference layer 23 of the tunnel junction 2. The current direction of adjacent bridge arms is opposite, thus making the magnetization direction of reference layer 23 opposite. The write line control terminal VEWL controls the switching of the write transistor; the actual wiring connection is not shown here.

[0062] In this embodiment, the magnetic field initialization process of the TMR full-bridge magnetic sensor is as follows: a voltage is applied to the write line control terminal VEWL to turn on the write transistor; the working signal input terminal Vbias and the differential output terminals V1 and V2 are suspended without voltage; the write voltage is written from the write signal input terminal Vwrite, and an auxiliary in-plane magnetic field is applied to generate a spin polarization current using the SOT effect, which flips the magnetic moment of the reference layer 23 in the tunnel junction 2 to a preset direction.

[0063] In the working state of the TMR full-bridge magnetic sensor: the write line control terminal VEWL and the write signal input terminal Vwrite are not energized, and the write transistor is turned off; the working voltage is connected from the working signal input terminal Vbias, and the differential voltage between the differential output terminals V1 and V2 is read.

[0064] See Figure 10 Furthermore, in this embodiment, to reduce the area of ​​the TMR full-bridge magnetic sensor, the number of pads in the TMR full-bridge magnetic sensor can be simplified. In this embodiment, a first transistor 7 and a second transistor 8 may also be included. The gates of the first transistor 7 and the second transistor 8 are both connected to the write word line EWL control terminal VEWL. The working signal input terminal Vbias is connected to the input pad 9 through the first transistor 7, and the write signal input terminal Vwrite is connected to the input pad 9 through the second transistor 8.

[0065] In this embodiment, only five pads are required: a ground pad corresponding to the ground terminal GND, two differential pads corresponding to the differential output terminals, a control pad corresponding to the write word line EWL control terminal VEWL, and input pads 9 corresponding to the working signal input terminal Vbias and the write signal input terminal Vwrite. Except for the input pads 9, each of these pads corresponds to its respective port. Specifically, for the working signal input terminal Vbias and the write signal input terminal Vwrite, a first transistor 7 and a second transistor 8 can be additionally provided in this embodiment. The gates of both the first transistor 7 and the second transistor 8 are connected to the write word line EWL control terminal VEWL and are controlled by it. The working signal input terminal Vbias is connected to the input pad 9 through the first transistor 7, and the write signal input terminal Vwrite is connected to the same input pad 9 through the second transistor 8. When initializing the TMR full-bridge magnetic sensor, the initialization signal input from the input pad 9 can be initialized by turning on the second transistor 8 and turning off the first transistor 7 through the spin orbital moment supply line 3 via the write signal input terminal Vwrite. When the TMR full-bridge magnetic sensor is working, the working signal input from the input pad 9 can be activated by turning on the first transistor 7 and turning off the second transistor 8 through the working signal input terminal Vbias to act on the Wheatstone full bridge. Thus, the working signal input terminal Vbias and the write signal input terminal Vwrite can share the same input pad 9 to complete the operation.

[0066] Specifically, in this embodiment, the first transistor 7 is a PMOS transistor, and the second transistor 8 is an NMOS transistor. The on / off state of the first transistor 7 and the second transistor 8 can be linked to the on / off state of the write transistor. Specifically, when an enable signal needs to be input to the write transistor to turn it on, this enable signal simultaneously causes the NMOS transistor to turn on and the PMOS transistor to turn off, thus turning on the second transistor 8 and turning off the first transistor 7. This allows the initialization signal input from the input pad 9 to flow through the spin orbital moment supply line 3 via the write signal input terminal Vwrite for initialization. When no enable signal is needed for the write transistor, the PMOS transistor turns on and the NMOS transistor turns off, thus turning on the first transistor 7 and turning off the second transistor 8. At this time, the working signal input from the input pad 9 acts on the Wheatstone full bridge through the working signal input terminal Vbias, allowing the differential voltages of the differential output terminals V1 and V2 to be read.

[0067] The TMR full-bridge magnetic sensor provided in this embodiment requires only 1-2 additional pads compared to the traditional Wheatstone full-bridge structure to write magnetic moments in different directions to different bridge arms, with controllable area. Furthermore, its method for setting the magnetization direction of the reference layer 23 is simple, low-cost, and highly efficient. By adjusting the MTJ series-parallel structure in array unit 5, the full-bridge output resistance and power consumption can be easily changed. This TMR full-bridge magnetic sensor is made from a single film stack, resulting in a small bridge arm resistance difference and stable full-bridge output. It can also correct for erroneous flipping caused by high temperature and strong magnetism by simply re-inputting the write signal through the EWL control terminal.

[0068] Example 3

[0069] This invention also provides a magnetic sensing device, which includes a TMR full-bridge magnetic sensor as provided in any of the above embodiments. Other structures in the magnetic sensing device can be found in the prior art and will not be described in detail here.

[0070] Since the magnetic sensing device in this embodiment uses the TMR full-bridge magnetic sensor provided in the above-described embodiments, it has a low cost and controllable area due to its simple structure and magnetization method. By adjusting the MTJ series-parallel structure in array unit 5, the full-bridge output resistance and power consumption can be easily changed, facilitating device development. It also has the advantages of small bridge arm resistance difference, stable full-bridge output, and the ability to correct for erroneous switching caused by high temperature and strong magnetism.

[0071] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0072] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0073] The present invention provides a detailed description of a TMR full-bridge magnetic sensor and magnetic sensing device. Specific examples have been used to illustrate the principles and implementation methods of the invention. The descriptions of these embodiments are merely illustrative of the method and core ideas of the invention. It should be noted that those skilled in the art can make various improvements and modifications to the invention without departing from its principles, and these improvements and modifications also fall within the scope of protection of the claims.

Claims

1. A TMR full-bridge magnetic sensor, characterized in that, It includes four bridge arms that form a Wheatstone full bridge; each bridge arm includes an initialization circuit and multiple array units connected in series, each array unit including multiple MTJ component structures; The MTJ component structure includes, from top to bottom, a top electrode, a tunnel junction, a spin orbital moment providing line, and two bottom electrodes located on the same layer; the reference layer in the tunnel junction is located close to the spin orbital moment providing line, one end of the spin orbital moment providing line is connected to one of the bottom electrodes, and the other end is connected to the other bottom electrode; multiple top electrodes are interconnected in the same array unit, and multiple spin orbital moment providing lines are connected through the bottom electrodes, so that multiple tunnel junctions in the same array unit are connected in parallel; The initialization circuit is connected to the bottom electrode to control the writing of the magnetic moment of the reference layer. The magnetic moment directions of each reference layer in the same single arm of the bridge are the same, and the magnetic moment directions of the reference layers in adjacent single arms of the bridge are opposite. Adjacent array units in the same single arm of the bridge are connected in series via adjacent top or bottom electrodes.

2. The TMR full-bridge magnetic sensor according to claim 1, characterized in that, Adjacent array units in the same single arm of the bridge are alternately connected in series via the connected top electrode and the bottom electrode; Two array units connected in series with their bottom electrodes form a write circuit unit. The bottom electrodes at both ends of the write circuit unit are connected to the control switch of the initialization circuit. The control switch includes a write transistor and a write word line connected to the gate of the transistor. One of the two write transistors is connected to the write signal input terminal, and the other write transistor is grounded.

3. The TMR full-bridge magnetic sensor according to claim 2, characterized in that, The Wheatstone full bridge is connected to a ground terminal, a differential output terminal, a working signal input terminal, a write line control terminal, and the write signal input terminal; the write line control terminal is connected to the write line.

4. The TMR full-bridge magnetic sensor according to claim 3, characterized in that, It also includes a first transistor and a second transistor, the gates of the first transistor and the second transistor are both connected to the write line control terminal, the working signal input terminal is connected to the input pad through the first transistor, and the write signal input terminal is connected to the input pad through the second transistor.

5. The TMR full-bridge magnetic sensor according to claim 4, characterized in that, The first transistor is a PMOS transistor, and the second transistor is an NMOS transistor.

6. The TMR full-bridge magnetic sensor according to claim 3, characterized in that, The grounding terminal, the differential output terminal, and the working signal input terminal are all connected to the top electrode.

7. The TMR full-bridge magnetic sensor according to claim 1, characterized in that, The array units are arranged in parallel.

8. The TMR full-bridge magnetic sensor according to claim 1, characterized in that, The number of MTJ component structures in the array unit is equal.

9. A magnetic sensing device, characterized in that, Including the TMR full-bridge magnetic sensor as described in any one of claims 1 to 8.

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