MAGNETIC FIELD SENSOR SYSTEM WITH MAGNETIC VORTEX FOR USE IN REFERENCE OF THE B-FIELD FOR A MAGNETIC FIELD OUTSIDE THE PLANE

Abstract

A magnetic sensor system comprises a magnetoresistive sensor, which includes a magnetic-free layer with a sensing plane and a magnetic-free magnetization arranged within the sensing plane, wherein the magnetic-free magnetization is variable in the presence of a magnetic field in the plane aligned with the sensing plane; and a ferromagnetic disk with a magnetic vortex in a ground state, wherein the magnetic vortex is configured to respond to an out-of-plane magnetic field and, in response to the out-of-plane magnetic field being applied to the ferromagnetic disk, to generate a stray field. The stray field has an in-plane magnetic field component proportional to the out-of-plane magnetic field. The magnetic-free layer is configured to receive the in-plane magnetic field component of the stray field.The magnetic-free magnetization is designed to change based on the in-plane magnetic field component of the stray field.

Description

BACKGROUND

[0001] Magnetic field sensors based on the magnetoresistive effect are called magnetoresistive sensors and are frequently used in magnetic field sensing applications, such as current, position, and angle sensing. Magnetoresistive is a property of a material that changes its electrical resistance when an external magnetic field is applied. Due to the high signal level and accuracy of magnetoresistive sensors, as well as the ability to integrate them into complementary metal-oxide-semiconductor (CMOS) and bipolar CMOS (BiCMOS) technologies, magnetoresistive sensors may be preferred over Hall-effect sensors.Some types of magnetoresistive sensors include anisotropic magnetoresistance (AMR) sensors, giant magnetoresistance (GMR) sensors, and tunnel magnetoresistance (TMR) sensors, each utilizing a corresponding magnetoresistive effect.

[0002] There are many applications where measuring electric current is desirable. For example, it might be desirable to measure one or more electric currents in the battery system of an electric vehicle. In another example, it might be desirable to measure one or more electric currents supplied to a load, such as an electric motor. Other examples include measuring one or more electric currents in a power distribution system or one or more electric currents in a circuit.

[0003] Since an electric current flowing through a current-carrying conductor generates a magnetic field with a magnetic flux density proportional to the magnitude of the electric current, magnetic field sensors can be used as current sensors. By placing a magnetic field sensor near the current-carrying conductor, the sensor can generate a measured quantity, such as a voltage, that is proportional to the magnetic field detected by the sensor. However, the magnetic flux density in the space around the current-carrying conductor decreases with increasing distance from the conductor. Therefore, a sensing element of the magnetic field sensor can be placed in close proximity to the current-carrying conductor.

[0004] Additionally, a magnetic field sensor can be used to detect the position of an object. For example, a magnet can be coupled to an object of interest (e.g., a target object). If the magnetic field sensor is placed in a fixed position, the magnetic field generated by the magnet and detected by the sensor changes when the object's position changes. For example, the magnetic flux density of the magnetic field incident on the sensor can increase as the object and magnet approach the sensor, and decrease as the object and magnet move further away. By placing the magnetic field sensor near the magnet's trajectory, it can thus generate a measurement, such as a voltage, that is proportional to the object's position relative to the magnetic field generated by the magnet. SUMMARY

[0005] There may be a need to provide an improved concept for a magnetic sensor system.

[0006] Such a need can be met by the subject matter of one of the claims.

[0007] In some implementations, a magnetic sensor system comprises a magnetoresistive sensor with a magnetic-free layer having a sensing plane and a magnetic-free magnetization arranged within the sensing plane, wherein the magnetic-free magnetization is variable when a magnetic field is present in the plane aligned with the sensing plane;and a ferromagnetic disk with a magnetic vortex in a ground state, wherein the magnetic vortex is configured to respond to an out-of-plane magnetic field and, responding to the out-of-plane magnetic field being applied to the ferromagnetic disk, to generate a stray field, wherein the stray field has an in-plane magnetic field component proportional to the out-of-plane magnetic field, wherein the magnetic-free layer is configured to receive the in-plane magnetic field component of the stray field, and wherein the magnetic-free magnetization is configured to change based on the in-plane magnetic field component of the stray field.

[0008] In some implementations, a magnetic sensor system comprises a first magnetoresistive sensor with a first sensitivity axis and a first magnetic-free layer with a first magnetic-free magnetization that is variable in the presence of an in-plane magnetic field aligned with the first sensitivity axis; a second magnetoresistive sensor with a second sensitivity axis and a second magnetic-free layer with a second magnetic-free magnetization that is variable in the presence of the in-plane magnetic field aligned with the second sensitivity axis; and a ferromagnetic disk with a magnetic vortex in a ground state, wherein the magnetic vortex is configured to respond to an out-of-plane magnetic field and, in response to the out-of-plane magnetic field being applied to the ferromagnetic disk, to generate a stray field.wherein the stray field decays with increasing distance from the ferromagnetic disk, wherein the first magnetoresistive sensor is arranged within the stray field and the second magnetoresistive sensor is arranged outside the stray field, wherein the stray field has an in-plane magnetic field component proportional to the out-of-plane magnetic field, wherein the first magnetic-free layer is configured to receive the in-plane magnetic field component of the stray field, and wherein the first magnetic-free magnetization is configured to change based on the in-plane magnetic field component of the stray field.

[0009] In some implementations, a magnetic sensor system comprises a ferromagnetic disk with a magnetic vortex in a ground state, wherein the magnetic vortex is configured to respond to an out-of-plane magnetic field and, responding to the out-of-plane magnetic field being applied to the ferromagnetic disk, to generate a stray field, wherein the stray field has a first in-plane magnetic field component and a second in-plane magnetic field component proportional to the out-of-plane magnetic field, and wherein the first in-plane magnetic field component has a first vector in a first direction and the second in-plane magnetic field component has a second vector in a second direction antiparallel to the first direction;a first magnetoresistive sensor with a first sensitivity axis and a first magnetic free layer with a first magnetic-free magnetization that is variable in the presence of an external magnetic field in the plane aligned with the first sensitivity axis;and a second magnetoresistive sensor with a second sensitivity axis and a second magnetic free layer with a second magnetic-free magnetization which is variable in the presence of the external magnetic field in the plane which is aligned with the second sensitivity axis, wherein the first sensitivity axis is parallel to the second sensitivity axis, wherein the first magnetoresistive sensor is arranged within the first in-plane magnetic field component of the stray field in order to detect the first vector, and wherein the second magnetoresistive sensor is arranged within the second in-plane magnetic field component of the stray field in order to detect the second vector. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Implementations are described herein with reference to the accompanying drawings. Fig. Figure 1 is a diagram of an exemplary magnetic field sensor according to one or more implementations. Fig. Figure 2 shows an example of a layer stack of a magnetoresistive detection element according to one or more implementations. Fig. Figure 3 shows an example of a magnetic sensor system according to one or more implementations. Fig. Figure 4A shows an example of a diagram of the magnetization of a ferromagnetic disk according to one or more implementations. Fig. Figure 4B shows an example of a diagram of a decay response of a plane-lying magnetic field component of a stray field according to one or more implementations. Fig. Figure 5 shows an example of a magnetic sensor system according to one or more implementations. Fig. Figure 6 shows an example of a magnetic sensor system according to one or more implementations. DETAILED DESCRIPTION

[0011] Details are provided below to offer a more comprehensive explanation of the exemplary implementations. However, it is obvious to experts in the field that these implementations can be carried out in practice without these specific details. In other cases, known structures and devices are shown in block diagram form or in a schematic view, rather than in detail, to avoid obscuring the implementations. Furthermore, features of the various implementations described herein may be combined unless specifically stated otherwise.

[0012] Furthermore, equivalent or identical elements, or elements with equivalent or identical functionality, are designated by equivalent or identical reference symbols in the following description. Since the same or functionally equivalent elements are given the same reference symbols in the figures, repeated descriptions for elements provided with the same reference symbols can be omitted. Thus, descriptions provided for elements with the same or similar reference symbols are mutually interchangeable.

[0013] Each of the depicted x-axis, y-axis, and z-axis is essentially perpendicular to the other two axes. In other words, the x-axis is essentially perpendicular to the y-axis and the z-axis, the y-axis is essentially perpendicular to the x-axis and the z-axis, and the z-axis is essentially perpendicular to the x-axis and the y-axis. In some cases, a single reference symbol refers to a surface, or fewer than all instances of a part may be labeled with all surfaces of that part. All instances of the part may include associated surfaces of that part, even if not every surface is labeled.

[0014] The orientations of the various elements in the figures are shown as examples, and the illustrated examples can be rotated relative to the orientations shown. The descriptions provided herein and the following claims apply to any structures exhibiting the described relationships between different features, regardless of whether the structures are in the particular orientation shown in the drawings or rotated relative to that orientation. Similarly, for the sake of simplicity, spatially relative terms such as "above," "below," "under," "below," "lower," "above," "upper," "middle," "left," and "right" may be used here to describe the relationship of one element to one or more other elements, as shown in the figures.The spatially relative terms are intended to encompass various orientations of the element, structure, and / or arrangement in use or operation, in addition to the orientations shown in the figures. A structure and / or arrangement may be oriented differently (rotated by 90 degrees or in other orientations), and the spatially relative descriptors used here may also be interpreted accordingly. Furthermore, the cross-sectional views in the figures show only features within the planes of the cross-sections and do not show materials behind the planes of the cross-sections, unless otherwise indicated, to simplify the drawings.

[0015] It should be noted that when an element is described as "connected" or "coupled" to another element, the element may be directly connected or coupled to the other element, or intermediate elements may exist. Conversely, when an element is described as "directly" "connected" or "coupled" to another element, no intermediate elements exist. Other expressions used to describe the relationship between elements should be interpreted similarly (e.g., "between" versus "directly between," "adjacent" versus "directly adjacent," etc.).

[0016] In implementations described herein or shown in the drawings, any direct electrical connection or coupling (e.g., any connection or coupling without any additional intervening elements) may also be implemented by an indirect connection or coupling (e.g., a connection or coupling with one or more additional intervening elements, or vice versa), as long as the general purpose of the connection or coupling (e.g., to transmit a certain type of signal or to transmit a certain type of information) is substantially maintained. Features of different implementations may be combined to form other implementations. For example, modifications or alterations described with respect to one of the implementations may also be applicable to other implementations unless otherwise specified.

[0017] In our usage, the terms "essentially" and "approximately" mean "within reasonable manufacturing and measurement tolerances." The terms "essentially" and "approximately" can be used here, for example, to account for small manufacturing tolerances or other factors (e.g., within 5%) that are considered acceptable in the industry without deviating from the aspects of the implementations described herein. For example, a resistor with an approximate resistance value may practically have a resistance value within 5% of that approximate value. As another example, a signal with an approximate signal value may practically have a signal value within 5% of that approximate value.

[0018] In the present disclosure, expressions including ordinal numbers, such as "first,r,s", "second,r,s", and / or the like, may modify various elements. However, such elements are not limited by the preceding expressions. For example, the preceding expressions do not restrict the sequence and / or importance of the elements. The preceding expressions are used merely for the purpose of distinguishing one element from the others. For example, a first box and a second box denote different boxes, although both are boxes. As another example, a first element could be designated as a second element, and similarly, a second element could be designated as a first element, without departing from the scope of protection of the present disclosure.

[0019] "Sensor" can refer to a component that converts a property to be measured into an electrical signal (e.g., a current or voltage signal). The property to be measured can be, but is not limited to, a magnetic field, an electric field, an electromagnetic wave (e.g., a radio wave), pressure, force, current, or voltage. For example, there are various sensor technologies for measuring a current flowing through a conductor or the position of an object in conjunction with a magnetic field. A system might include, for instance, a current-carrying conductor carrying a current to be measured. A magnetic field sensor can detect a magnetic field generated by the current and produce a sensor signal proportional to that magnetic field. Thus, the sensor signal can be a measure of the current.

[0020] As another example, a system can include a magnet coupled to a moving target object. The magnet can move relative to a magnetic field sensor as the moving target object travels along a predetermined path. As the magnet moves closer to the magnetic field sensor, the magnetic field generated by the magnet can become denser (e.g., more concentrated or stronger) in a region of the sensor. Conversely, as the magnet moves farther away from the sensor, the magnetic field in the sensor region can become less dense (e.g., less concentrated or weaker). The magnetic field sensor can detect the magnetic field generated by the magnet and produce a sensor signal proportional to the magnetic field. Thus, the sensor signal can be a measure of the magnet's position relative to the magnetic field sensor.

[0021] As another example, a magnet can be coupled to a magnetic field sensor as a back-bias magnet. A moving target object can be configured to influence the magnetic field of the back-bias magnet as it moves along a predetermined path. The moving target object can, for example, be made of a ferromagnetic material. As a result, the magnetic field in a region of the magnetic field sensor can become denser (e.g., more concentrated or stronger) as the moving target object moves closer to the back-bias magnet, and it can become less dense (e.g., less concentrated or weaker) in the region of the magnetic field sensor as the moving target object moves farther away from the back-bias magnet. The magnetic field sensor can detect the magnetic field generated by the back-bias magnet and produce a sensor signal proportional to the magnetic field.Thus, the sensor signal can be a measure of the position of the moving target object relative to the magnetic field sensor.

[0022] Due to their shape anisotropy, magnetization in magnetoresistive-based sensors is typically in-plane. Therefore, magnetoresistive-based sensors can only detect in-plane magnetic fields (i.e., in-plane B-fields) and cannot detect out-of-plane magnetic fields (i.e., out-of-plane B-fields). An in-plane magnetic field is a magnetic field aligned parallel to a chip plane (e.g., a chip surface) of the magnetoresistive-based sensor, while an out-of-plane magnetic field is a magnetic field that extends beyond the chip plane (e.g., the chip surface) of the magnetoresistive-based sensor. However, in some applications, it may be desirable to use magnetoresistive-based sensors to detect and / or measure an out-of-plane magnetic field.

[0023] Accordingly, some implementations disclosed here are directed towards a magnetic field sensor system comprising a ferromagnetic disk configured to redirect an out-of-plane magnetic field, via the stray field, into a detection plane of a magnetoresistive-based sensor such that the magnetoresistive-based sensor is able to measure the out-of-plane magnetic field. The ferromagnetic disk may, for example, exhibit a magnetic vortex in a ground state. In other words, the ferromagnetic disk may have a closed-flux magnetization that is in a vortex state. The magnetic vortex of the ferromagnetic disk may be configured to respond linearly to the out-of-plane magnetic field and, responding to the application of the out-of-plane magnetic field to the ferromagnetic disk, generate the stray field.The stray field can have an in-plane magnetic field component proportional to the out-of-plane magnetic field, and a magnetic free layer of the magnetoresistive-based sensor can be configured to receive the in-plane magnetic field component of the stray field such that the magnetic free layer's magnetization changes based on the in-plane magnetic field component of the stray field. Consequently, the ferromagnetic disk enables the magnetoresistive-based sensor to measure the out-of-plane magnetic field by converting it into the stray field with the in-plane magnetic field component that can be detected by the magnetoresistive-based sensor.

[0024] The magnetic vortex is generated within the ferromagnetic disk based on the disk's volume. The disk thickness can be less than 600 nm while still being capable of generating and maintaining the magnetic vortex. Additionally, the magnetic vortex exhibits a linear stray field response defined by the disk's aspect ratio. This aspect ratio is the ratio between the disk's thickness and its diameter. Thus, the magnetic vortex provides a linear response to the out-of-plane magnetic field such that the in-plane component of the stray field has a linear relationship to the out-of-plane magnetic field.The ability of the magnetic vortex of the ferromagnetic disk to linearly redirect the out-of-plane magnetic field as an in-plane magnetic field component allows the ferromagnetic disk to be thin (e.g., less than 600 nm thick), which offers an advantage over more expensive redirection methods in terms of material and manufacturing costs. The ferromagnetic disk can be made of a soft ferromagnetic material (e.g., iron or an iron alloy such as nickel-iron (NiFe)), and its thickness can be less than 600 nm, 500 nm, 400 nm, 300 nm, 200 nm, or 100 nm.Furthermore, it is only necessary that the ferromagnetic disk be positioned within the out-of-plane magnetic field and close enough to the magnetoresistive-based sensor such that the sensor receives a portion of the stray field that responds linearly to the out-of-plane magnetic field. Thus, the ferromagnetic disk may be easier to integrate into a magnetic field sensor system than other, more complex redirection methods. This simplified integration can lead to reduced manufacturing costs.

[0025] Additionally, homogeneous magnetic fields present at a magnetic field sensor can interfere with the magnetic field being measured. A homogeneous magnetic field can be generated, for example, by a nearby busbar, as is common in electric vehicles, or by another magnetic field source. A homogeneous magnetic field incident on the magnetic field sensor can cause the sensor to output a signal that is not an accurate measurement of the magnetic field being measured. Thus, sensitivity to homogeneous magnetic fields can cause the magnetic field sensor to output unreliable sensor information, which can lead to a system that relies on this sensor information malfunctioning.Additionally, sensitivity to homogeneous magnetic fields can create an unsafe environment for a user or an object used in conjunction with the magnetic field sensor when the sensor is used in safety-critical applications. Therefore, in some implementations, a magnetic sensor system may be configured to cancel homogeneous magnetic fields.

[0026] Fig. Figure 1 is a diagram of an exemplary magnetic field sensor 100 according to one or more implementations. As in Fig. As shown in Figure 1, the magnetic sensor 100 can comprise one or more sensing elements 110 (e.g., one or more magnetic field sensing elements), an analog-to-digital converter (ADC) 120, a digital signal processor (DSP) 130, a memory component 140, and an interface 150.

[0027] The magnetic field sensor 100 can be a semiconductor chip (e.g., a sensor chip) comprising one or more sensing elements 110 that measure or otherwise detect one or more characteristics of a magnetic field (e.g., the magnitude of the magnetic field flux density, the field strength, the field angle, the field direction, the field orientation, etc.) and provide a sensor signal corresponding to the detected characteristics of the magnetic field. For example, a sensing element 110 can be configured to generate a sensor signal (e.g., a voltage or a measurable resistance) in response to one or more magnetic fields acting upon the sensing element 110. Thus, the sensor signal indicates a magnitude and / or field orientation of at least one magnetic field acting upon the sensing element 110.The semiconductor chip may further include a sensor circuit arrangement for processing and outputting one or more sensor signals generated by the one or more sensing elements 110. In some implementations, the sensing elements 110 may be distributed across two or more semiconductor chips.

[0028] The magnetic field can be generated by a magnet, a current-carrying conductor (e.g., a wire, a conduit frame, or a busbar), the ground, or another magnetic field source. A sensing element 110 has a "sensitivity axis" or "sensing axis." The sensing element is sensitive to a magnetic field component of a magnetic field that is projected onto or aligned with the sensitivity axis. Furthermore, a sensing element 110 is essentially insensitive to magnetic field components of a magnetic field that are not projected onto or aligned with the sensitivity axis. A magnetic field component can be, for example, an x-magnetic field component Bx, a y-magnetic field component By, or a z-magnetic field component Bz.In the examples described here, the x-magnetic field component Bx and the y-magnetic field component By are aligned in the plane of the semiconductor chip, while the z-magnetic field component Bz is aligned out of the plane. Accordingly, the x-magnetic field component Bx and the y-magnetic field component By can be described as "in-plane" magnetic field components, aligned parallel to a chip plane (e.g., a chip surface) of the semiconductor chip. In contrast, the z-magnetic field component Bz can be described as an "out-of-plane" magnetic field component, extending outside the chip plane (e.g., a chip surface) of the semiconductor chip. The z-magnetic field component Bz extends, for example, perpendicular to the chip plane.

[0029] In some implementations, the magnetic field sensor 100 comprises several sensing elements 110 that are sensitive in two or more different directions. For example, the magnetic field sensor 100 may include a first sensing element configured to detect a first magnetic field component (e.g., the x-magnetic field component Bx), a second sensing element configured to detect a second magnetic field component (e.g., the y-magnetic field component By), and a third Hall-based sensing element configured to detect a third magnetic field component (e.g., the z-magnetic field component Bz). That is, in some implementations, the magnetic field sensor 100 may be a 2D magnetic field sensor or a 3D magnetic field sensor configured to detect the magnetic field in multiple dimensions.

[0030] The detection elements 110 can comprise one or more magnetoresistive-based detection elements (i.e., magnetoresistive detection elements). Magnetoresistive is a property of a magnetoresistive material (e.g., NiFe) to change the value of its electrical resistance or electrical conductivity when a magnetic field is applied to the magnetoresistive material. Thus, the electrical resistance of the magnetoresistive material can depend on the strength and / or direction of the magnetic field present at the magnetoresistive material.Some examples of different magnetoresistive effects are: giant magnetoresistance (GMR), which is a quantum mechanical magnetoresistive effect observed in thin-film structures composed of alternating ferromagnetic and non-magnetic conductive layers; tunnel magnetoresistance (TMR), which is a magnetoresistive effect occurring at a magnetic tunnel junction (MTJ), a component comprising two ferromagnets separated by a thin insulator; or anisotropic magnetoresistance (AMR), which is a property of a material in which a dependence of the electrical resistance on an angle between a direction of electric current and a direction of magnetization is observed.For example, in the case of AMR sensors, the resistance of an AMR sensing element changes according to the square of the sine of the angle of the magnetic field component projected onto the sensitivity axis of the AMR sensing element.

[0031] The majority of magnetoresistive effects are commonly abbreviated as xMR, where the "x" serves as a placeholder for the various magnetoresistive effects. xMR sensors can detect the field orientation of an applied magnetic field by measuring sine and cosine angular components using monolithically integrated magnetoresistive sensing elements.

[0032] Magnetoresistive sensing elements of such xMR sensors typically comprise multiple layers, at least one of which is a reference layer with a reference magnetization (i.e., a reference direction). The reference magnetization provides a sensing direction that defines the sensitivity axis of a magnetoresistive sensing element. This generally means that the sensitivity axis of the magnetoresistive sensing element is parallel to the chip plane defined by a major surface of the semiconductor chip into which the magnetoresistive sensing element is integrated. Consequently, a magnetoresistive sensing element is sensitive to the magnetic field component that extends parallel to or in the same plane as the major surface of the semiconductor chip.Accordingly, if a magnetic field component points in exactly the same direction as the reference direction, the resistance of the magnetoresistive sensing element is at a maximum, and if the magnetic field component points in exactly the opposite direction with respect to the reference direction, the resistance of the magnetoresistive sensing element is at a minimum.

[0033] Consequently, the resistance or voltage drop across the magnetoresistive sensing element, resulting from the resistance, is proportional to the magnetic field and can be used as the sensor signal of the magnetoresistive sensing element. Furthermore, in some implementations, an xMR sensor comprises multiple magnetoresistive sensing elements that may have the same or different reference magnetizations.

[0034] Accordingly, magnetoresistive sensing elements can be used to measure magnetic fields parallel to the chip plane of the magnetic field sensor 100. Two or more sensing elements and a corresponding sensor circuit arrangement can be housed (e.g., integrated) on a single semiconductor chip. The sensor circuit arrangement can be referred to as a signal processing circuit arrangement and / or signal conditioning circuit arrangement, which receives one or more signals (i.e., sensor signals) from one or more sensing elements in the form of raw measurement data and derives a measurement signal representing the magnetic field from the one or more signals. For example, the sensor circuit arrangement can be configured to condition and amplify the sensor signal of one or more sensing elements 110 via signal processing and / or conditioning.

[0035] In some implementations, the sensor circuit arrangement may be configured to combine two or more sensor signals (e.g., by addition, subtraction, or superposition) to generate a combined sensor signal. A differential sensor signal, for example, is a type of combined sensor signal that represents a difference between two sensor signals. In some cases, the sensor circuit arrangement may generate the differential sensor signal from the sensor signals produced by two or more sensing elements 110 with the same sensitivity axis (e.g., two sensing elements 110 that are sensitive to the same magnetic field component), using a differential circuit arrangement configured to combine the signals differentially. Sensing elements that are electrically connected in a full-bridge configuration or in a full-bridge configuration (e.g.,A Wheatstone bridge is one example of a differential circuit arrangement that can be used to generate differential sensor signals. Additionally or alternatively, the differential circuit arrangement can include a differential amplifier, an adder, a subtractor, a combiner, a logic circuit arrangement, and / or a processor (e.g., a processor that applies differential calculus) to differentially combine the signals to generate a differential sensor signal. Thus, the differential sensor signal can be a measurement signal that provides robustness against homogeneous external stray magnetic fields.

[0036] The above-described examples of sensing elements 110 are provided for illustrative purposes and in practice the sensing elements 110 may include any type of magnetoresistive sensing element capable of detecting a characteristic of a magnetic field and enabling the provision of a sensor signal to the sensor circuit arrangement.

[0037] The ADC 120 can include an analog-to-digital converter that converts an analog signal from one or more sensing elements 110 into a digital signal. For example, the ADC 120 can convert analog signals received from the set of sensing elements 110 into digital signals (e.g., digital samples) to be processed by the DSP 130. The ADC 120 can then provide the digital signals to the DSP 130. In some implementations, the magnetic field sensor 100 can include one or more ADCs 120. For example, different ADCs 120 can be configured to receive analog signals from different sets of sensing elements 110.

[0038] The DSP 130 can comprise a digital signal processing device or a collection of digital signal processing devices. In some implementations, the DSP 130 can receive digital signals from the ADC 120 and process these digital signals to form output signals (e.g., intended for control), such as an output signal transmitting sensor data, as described elsewhere herein. In some implementations, the output signals may be referred to as measurement signals.

[0039] The memory element 140 can comprise read-only memory (ROM) (e.g., an EEPROM), random-access memory (RAM), and / or another type of dynamic or static storage device (e.g., flash memory, magnetic storage, optical storage, etc.) that stores information and / or instructions for use by the magnetic field sensor 100. In some implementations, the memory element 140 can store information associated with the processing performed by the DSP 130. Additionally or alternatively, the memory element 140 can store configuration values ​​or parameters for one or more sensing elements 110 and / or information for one or more other components of the magnetic field sensor 100, such as the ADC 120 or the interface 150.

[0040] Interface 150 can include an interface through which the magnetic field sensor 100 can receive information from and / or provide information to another device in a system, such as a controller. For example, interface 150 can provide the output signal determined by the DSP 130 or otherwise generated to the controller and can also receive information from the controller 112. In some implementations, interface 150 can be a communication interface that receives the output signals from the DSP 130 and provides the output signals as communication signals according to a communication protocol, which may include transmitting the output signals as communication signals or generating communication signals based on the output signals.

[0041] As shown above, Fig. 1 is provided as an example. Other examples may differ from what is provided in relation to Fig. As described in section 1, the number and arrangement of in Fig. The components shown in Figure 1 are provided as an example. In practice, the magnetic field sensor may include 100 additional components, fewer components, different components, or components arranged differently than those shown in Figure 1. Fig. 1 are shown. Two or more components that are in Fig. The elements shown in 1 can be implemented within a single component, or a single component that is in Fig. Figure 1 shows that the magnetic field sensor 100 can be implemented as multiple, distributed components. Additionally or alternatively, a set of components (e.g., one or more components) of the magnetic field sensor 100 can perform one or more functions that are described as being performed by another set of components of the magnetic field sensor 100.

[0042] Fig. Figure 2 shows an example of a layer stack of a magnetoresistive sensing element 200 according to one or more implementations. The magnetoresistive sensing element 200 can, for example, be a TMR sensing element with a bottom-pinned spin-valve (BSV) configuration. Additionally, the magnetoresistive sensing element 200 can be arranged on a semiconductor substrate (not shown) of a magnetoresistive sensor. When described in a Cartesian coordinate system with pairwise perpendicular coordinate axes x, y, and z, the layers of the layer stack extend laterally in a plane spanned by the x and y axes. Thus, lateral dimensions (e.g., lateral distances, lateral cross-sectional areas, lateral regions, lateral extents, lateral displacements, etc.) can be represented.) refer to dimensions in the xy-plane and vertical dimensions refer to dimensions in a z-direction perpendicular to the xy-plane. For example, the vertical extent of a layer in the z-direction can be described as layer thickness.

[0043] The layer stack of the magnetoresistive sensing element 200 comprises at least one reference layer with a reference magnetization (e.g., a reference direction in the case of GMR or TMR technology). The reference magnetization is a magnetization direction that provides a sensing direction corresponding to a sensing axis of the magnetoresistive sensing element 200. The reference layer, and consequently the reference magnetization, defines a sensor plane. The sensor plane can be defined, for example, by the xy-plane. Thus, the x-direction and the y-direction can be described as "in-plane" with respect to the sensor plane, while the z-direction can be described as "out-of-plane" with respect to the sensor plane.

[0044] Accordingly, in the case of a GMR or TMR detection element, when the magnetic-free magnetization of a magnetic free layer points in exactly the same direction as the reference magnetization (e.g., the reference direction), the resistance of the magnetoresistive detection element 200 is at a minimum, and when the magnetic-free magnetization of the magnetic free layer points in exactly the opposite direction to the reference magnetization, the resistance of the magnetoresistive detection element 200 is at a maximum. The orientation of the magnetic-free magnetization of the magnetic free layer is variable in the presence of an external magnetic field.In a magnetoresistive sensing element with a magnetic vortex-free layer, the magnetic-free magnetization of the magnetic-free layer is in the form of a magnetic vortex, which is a circular magnetization pattern with a core at its center. When an external magnetic field is applied to the magnetic-free layer, the external magnetic field can displace the core of the magnetic vortex and change the resistance or conductivity of the magnetoresistive sensing element. Thus, the resistance or conductivity of the magnetoresistive sensing element can vary based on the influence of the external magnetic field on the magnetic-free magnetization of the magnetic-free layer.

[0045] From bottom to top, the magnetoresistive sensing element 200 may include an optional seed layer 202, which is used to influence and / or optimize stack growth. In some implementations, the seed layer 202 may comprise copper, tantalum, ruthenium, or a combination thereof. A natural antiferromagnetic (NAF) layer 204 is formed or otherwise arranged on the seed layer 202. The NAF layer 204 may be made of platinum-manganese (PtMn), iridium-manganese (IrMn), nickel-manganese (NiMn), or similar materials. The NAF film thickness may range from 5 nm to 50 nm.

[0046] Additionally, a pinned layer (PL) 206 can be formed or otherwise arranged on the NAF layer 204. The pinned layer 206 can be made of a ferromagnetic material, e.g., cobalt-iron (CoFe) or cobalt-iron-boron (CoFeB). Contact between the NAF layer 204 and the pinned layer 206 can induce an effect known as the exchange bias effect, which causes the magnetization of the pinned layer 206 to align in a preferred direction (e.g., in the x-direction, as shown). The magnetization of the pinned layer 206 can be referred to as pinned magnetization. The pinned layer 206 can exhibit a closed-flux magnetization pattern in the xy-plane. This closed-flux magnetization pattern of the pinned layer 206 can be generated during the fabrication of the magnetoresistive sensing element 200 and can be permanently fixed.Alternatively, the pinned layer 206 can have a linear magnetization pattern in the xy-plane (e.g. a homogeneous orientation in one direction) that is permanently fixed.

[0047] The magnetoresistive sensing element 200 further comprises a non-magnetic layer (NML) referred to as a coupling intermediate layer 208. The coupling intermediate layer 208 can be diamagnetic and may consist of, for example, ruthenium, iridium, copper, copper alloys, or similar materials. A magnetic (e.g., ferromagnetic) reference layer (RL) 210 can be formed on the coupling intermediate layer 208 or arranged otherwise. The thicknesses of the pinned layer 206 and the magnetic reference layer 210 can each be in the range of 1 nm to 10 nm.

[0048] Accordingly, the coupling intermediate layer 208 can be arranged between the pinned layer 206 and the magnetic reference layer 210 to spatially separate the pinned layer 206 and the magnetic reference layer 210 in the vertical direction. Additionally, the coupling intermediate layer 208 can provide an interlayer exchange coupling (e.g., an antiferromagnetic Rudennan-Kittel-Kasuya-Yosida-RKKY coupling) between the pinned layer 206 and the magnetic reference layer 210 to form an artificial antiferromagnet. Thus, the magnetization of the magnetic reference layer 210 can be oriented and held in a direction antiparallel or opposite to the magnetization of the pinned layer 206 (e.g., in the -x direction, as shown). The magnetization of the magnetic reference layer 210 can be referred to as the reference magnetization.

[0049] Since the NAF layer 204 is configured to cause the magnetization of the pinned layer 206 to be oriented and fixed in a specific direction, and the coupling intermediate layer 208 is configured to cause the magnetization of the magnetic reference layer 210 to be oriented and fixed in an opposite direction, it can be said that the NAF layer 204 is configured to hold the magnetization of the pinned layer 206 (e.g., a fixed pinned magnetization) in a first magnetic orientation and to hold the magnetization of the magnetic reference layer 210 (e.g., a fixed reference magnetization) in a second magnetic orientation. Furthermore, if the pinned layer 206 comprises a linear magnetization pattern in the xy-plane in a specific direction, the magnetic reference layer 210 can comprise a linear magnetization pattern in an antiparallel direction.Thus, the NAF layer 204, the pinned layer 206, the coupling intermediate layer 208 and the magnetic reference layer 210 form a magnetic reference layer system 212 of the magnetoresistive sensing element 200.

[0050] The magnetoresistive detection element 200 additionally comprises a barrier layer 214 (e.g., a tunnel barrier layer) arranged vertically between the reference layer system 212 and a magnetically free layer 216. For example, the barrier layer 214 can be formed on the magnetic reference layer 210 of the reference layer system 212 or arranged otherwise, and the magnetically free layer 216 can be formed on the barrier layer 214 or arranged otherwise.

[0051] Barrier layer 214 can be made of a non-magnetic material. In some implementations, barrier layer 214 can be an electrically insulating tunnel barrier layer. For example, barrier layer 214 can be a tunnel barrier layer used to generate a TMR effect. Barrier layer 214 can be made of magnesium oxide (MgO) or another material with similar properties.

[0052] The material of the magnetic-free layer 216 can be an alloy of a ferromagnetic material, such as CoFe, CoFeB, or NiFe. The magnetic-free layer 216 exhibits a magnetic-free magnetization that is variable in the presence of an external magnetic field in the plane. Therefore, the magnetic-free layer 216 can be referred to as a sensor layer, since changes in the magnetic-free magnetization are used to determine a measured quantity (e.g., the electrical resistance or electrical conductivity of the magnetoresistive sensing element). Additionally, the magnetic-free magnetization has a standard magnetic orientation in a ground state. The ground state is a state in which the influence of the external magnetic field in the plane on the magnetic-free layer 216 is either non-existent or negligibly small.In some implementations, the magnetoresistive sensing element 200 can comprise a magnetic-free system that includes a plurality of layers (e.g., two or more magnetic-free layers) which, in combination, function as the magnetic-free layer. In this case, the magnetic-free layers of the magnetic-free system are magnetically coupled to one another. Thus, the magnetic-free system can function as the magnetic-free layer but can comprise a plurality of layers. The magnetic-free layer exhibits a magnetic-free magnetization, which is variable in the presence of the external magnetic field in the plane.

[0053] The magnetic-free magnetization of the magnetic-free layer 216 can be a magnetic vortex-free layer with a closed-flux magnetization that is in a vortex state. In other words, a magnetization pattern of the magnetic-free magnetization can form a closed loop. As a result, the magnetoresistive sensing element 200 exhibits an electrical conductivity or electrical resistance, and the magnetoresistive sensing element 200 can be configured to exhibit a linear change in electrical conductivity or electrical resistance that is proportional to the external magnetic field in the plane, based on a linear change in the magnetic-free magnetization of the magnetic-free layer 216 that responds to the external magnetic field in the plane (e.g., proportionally to it).Thus, the magnetoresistive sensing element 200 can be a linear magnetoresistive sensor that exhibits a linear sensor response to the external magnetic field in the plane.

[0054] A cover layer 218, made of, for example, tantalum (Ta), tantalum nitride (TaN), ruthenium (Ru), titanium (Ti), titanium nitride (TiN), platinum (Pt) or the like, can be formed on the magnetic-free layer 216 or otherwise arranged to form an upper layer of the magnetoresistive sensing element 200.

[0055] The seed layer 202 can serve as a lower electrode or can provide electrical contact with a lower electrode (not shown) of the magnetoresistive sensing element 200. The cover layer 402 can provide electrical contact with an upper electrode (not shown) of the magnetoresistive sensing element 200. The barrier layer 214 can be designed to allow electrons to tunnel between the reference layer system 212 and the magnetically free layer 216 when a bias voltage is applied to electrodes of the magnetoresistive sensing element 200 (not shown) to provide a magnetoresistive effect (e.g., a TMR effect).

[0056] As shown above, Fig. 2 is provided merely as an example. Other examples may differ from what is provided in relation to Fig. As described in section 2, the number and arrangement of in Fig. The two components shown are provided as an example. In practice, the magnetoresistive detection element can comprise 200 additional elements, fewer elements, different elements, or elements arranged differently than those shown. Fig. 2 are shown.

[0057] Fig. Figure 3 shows an example of a magnetic sensor system 300 according to one or more implementations. The magnetic sensor system 300 can comprise a magnetoresistive sensor 302 and a ferromagnetic disk 304, which is spatially separated from the magnetoresistive sensor 302. The magnetoresistive sensor 302 can be a magnetoresistive sensing element similar to that associated with Fig. The magnetoresistive sensing element 200 described in Section 2 can be a linear magnetoresistive sensor comprising a magnetic vortex-free layer as the magnetic-free layer 306. The magnetic-free layer 306 is used as a sensing layer for detecting magnetic fields in the plane. The magnetic-free layer 306 can, for example, have a sensing plane (e.g., an xy-plane) and a magnetic-free magnetization located within the sensing plane. Additionally, the magnetic-free magnetization is variable when a magnetic field is present in the plane that is aligned with the sensing plane (e.g., aligned with a sensitivity axis of a magnetic reference layer (not explicitly shown)).

[0058] The ferromagnetic disk 304 can be made of a soft magnetic material and can exhibit a magnetic vortex in a ground state. Thus, the ferromagnetic disk 304 can have a closed-flux magnetization in a vortex state. The ferromagnetic disk 304 is configured to respond to an out-of-plane magnetic field, such as a magnetic field located outside the sensing plane, and to generate a stray field in response to the application of the out-of-plane magnetic field to the ferromagnetic disk 304. In some implementations, the out-of-plane magnetic field can be a Bz field oriented orthogonally to the sensing plane in the z-direction. The stray field generated by the magnetic vortex of the ferromagnetic disk 304 can include an in-plane magnetic field component proportional to the out-of-plane magnetic field.In other words, the ferromagnetic disk 304 can be configured to convert the out-of-plane magnetic field into the stray field with the in-plane magnetic field component. Consequently, the ferromagnetic disk 304 can be configured to redirect the out-of-plane magnetic field, as the stray field, into the detection plane of the magnetic free layer 306 such that the in-plane magnetic field component of the stray field is aligned with the detection plane of the magnetic free layer 306.

[0059] Additionally, the magnetic vortex provides a linear response (e.g., a linear stray field response) to the out-of-plane magnetic field such that the in-plane magnetic field component of the stray field has a linear relationship to the out-of-plane magnetic field. Thus, the ferromagnetic disk 304 generates the in-plane magnetic field component of the stray field from the out-of-plane magnetic field based on a linear response function, and the in-plane magnetic field component of the stray field has a linear relationship to the out-of-plane magnetic field based on the linear response function.

[0060] The magnetically free layer 306 is configured to receive the in-plane magnetic field component of the stray field, and the magnetically free magnetization of the magnetically free layer 306 is configured to change based on the in-plane magnetic field component of the stray field. That is, the magnetically free layer 306 is positioned at a location where the presence of the in-plane magnetic field component of the stray field is expected. Since the change in the magnetically free magnetization is proportional to the in-plane magnetic field component, and the in-plane magnetic field component is proportional to the out-of-plane magnetic field, the change in the magnetically free magnetization is also proportional to the out-of-plane magnetic field. Thus, the change in the magnetically free magnetization can represent a magnitude of the magnetic field flux density or a field strength of the out-of-plane magnetic field.

[0061] An aspect ratio between the thickness and diameter of the ferromagnetic disk 304 defines a linear region of the stray field. This linear region of the stray field responds linearly to the out-of-plane magnetic field based on a linear response function. The magnetically free magnetization of the magnetically free layer 306 responds linearly to this linear region of the stray field. Therefore, the magnetically free layer 306 should be positioned at a location where the in-plane magnetic field component of the stray field exhibits a linear response to the out-of-plane magnetic field.

[0062] The magnetic vortex of the ferromagnetic disk 304 is generated within the disk based on its volume and can be produced using a relatively thin soft ferromagnetic layer. The thickness of the ferromagnetic disk can be, for example, less than 600 nm, 500 nm, 400 nm, 300 nm, 200 nm, or 100 nm. Additionally, the linear stray field response of the magnetic vortex is defined by the aspect ratio of the ferromagnetic disk 304. The ability of the magnetic vortex of the ferromagnetic disk 304 to linearly and hysteresis-free redirect the out-of-plane magnetic field component of the in-plane magnetic field for local B-field redirection allows the ferromagnetic disk 304 to be kept thin.Furthermore, the ferromagnetic disk 304 does not generate a measurable stray field at the magnetically free layer 306 when no external magnetic field is applied to the ferromagnetic disk 304. The stray field can decay rapidly with increasing distance from the ferromagnetic disk 304, depending on the volume of the ferromagnetic disk 304.

[0063] The magnetoresistive sensor 302 exhibits an electrical conductivity or resistance that changes based on changes in the magnetoresistive magnetization of the magnetic free layer 306. Thus, the magnetoresistive sensor 302 is configured to exhibit a linear change in electrical conductivity or resistance proportional to the out-of-plane magnetic field, based on changes in the magnetoresistive magnetization of the magnetic free layer 306 responding to the in-plane magnetic field component of the stray field. A sensor circuit can be used to read or measure the electrical conductivity or resistance of the magnetoresistive sensor 302.

[0064] The number and arrangement of in Fig. The three components shown are provided as an example. In practice, the magnetic sensor system may include 300 additional components, fewer components, different components, or components arranged differently than those shown. Fig. 3 are shown.

[0065] Fig. Figure 4A shows an example of diagram 400A of the magnetization of a ferromagnetic disk according to one or more implementations. Diagram 400A shows a relative magnetization (m oop ) of the ferromagnetic disk 304 outside the plane (oop) as a function of an external magnetic field outside the plane (µ0 H) 00PIn this example, the ferromagnetic disk has a diameter of 500 nm, which is kept constant for different disk thicknesses. The aspect ratio (thickness / diameter) defines the shape anisotropy and thus the slope of the magnetization curve. The generated stray field is directly proportional to the magnetization.

[0066] A linear region of the stray field response of the ferromagnetic disk depends on the aspect ratio of the disk. Therefore, the linear stray field response of the ferromagnetic disk can be controlled by the aspect ratio. Since the diameter is kept constant in this example, the linear region of the stray field response depends on the thickness of the ferromagnetic disk. Diagram 400A shows that a smaller thickness of the ferromagnetic disk results in a larger linear region for the stray field response. Thus, the thickness of the ferromagnetic disk can be less than 500 nm and still provide a linear stray field response suitable for measuring the out-of-plane magnetic field. Additionally, the sensitivity of the ferromagnetic disk to the out-of-plane magnetic field can be increased at the expense of the linear region.

[0067] As shown above, Fig. 4A is provided only as an example. Other examples may differ from what is provided in relation to Fig. As described in 4A, they differ.

[0068] Fig. Figure 4B shows an example of diagram 400B of the decay response of an in-plane magnetic field component of a stray field according to one or more implementations. Diagram 400B shows the change in magnetic flux density (mT) of an in-plane magnetic field component of a stray field relative to a distance (µm) along a sensitivity axis direction of a magnetoresistive sensor. Diagram 400B shows three sketches for three different z-distances between the magnetoresistive sensor and a ferromagnetic disk (e.g., ferromagnetic disk 304).

[0069] The stray field generated by the ferromagnetic disk due to an out-of-plane magnetic field decays rapidly with increasing distance along the sensitivity axis from the disk in some cases. Therefore, a magnetoresistive sensor should be positioned where the stray field of the ferromagnetic disk 304 can be detected. For example, a 500 nm (diameter) by 300 nm (thickness) ferromagnetic disk can saturate at an out-of-plane field of 500 mT. At a distance of approximately 500 nm, the in-plane component of the stray field can be about 50 mT. Thus, in this example, about 10% of the external magnetic field can be deflected out of the plane.

[0070] As shown above, Fig. 4B is provided as an example. Other examples may differ from what is provided in relation to Fig. As described in 4B, they differ.

[0071] Fig. Figure 5 shows an example of a magnetic sensor system 500 according to one or more implementations. The magnetic sensor system 500 can be used to measure an out-of-plane magnetic field (e.g., an out-of-plane magnetic field component of an external magnetic field) if an external magnetic field has an out-of-plane magnetic field component and at least one in-plane magnetic field component. The magnetic sensor system 500 can include the magnetoresistive sensor 302 and the ferromagnetic disk 304, as described in the context of the magnetic sensor system 300 of Figure 5. Fig. 3 described. Additionally, the magnetic sensor system 500 can include an additional magnetoresistive sensor 502, which has a magnetically free layer 504 (e.g., a sensing layer) with a magnetically free magnetization (e.g., a magnetic vortex). The external magnetic field can be a homogeneous magnetic field extending through both the magnetoresistive sensor 302 and the magnetoresistive sensor 502.

[0072] The magnetoresistive sensor 502 can be similar to the magnetoresistive sensor 302, with a similar layer stack and similar magnetizations within the layers of the layer stack. For example, both the magnetoresistive sensor 302 and the magnetoresistive sensor 502 can each have a magnetic vortex-free layer and a magnetic reference layer with a fixed reference magnetization aligned with the same axis in the plane (e.g., an x-axis or a y-axis). Since the fixed reference magnetization defines a sensitivity axis of a magnetoresistive sensor, both the magnetoresistive sensor 302 and the magnetoresistive sensor 502 can have a sensitivity axis aligned with the same axis in the plane. Consequently, both the magnetoresistive sensor 302 and the magnetoresistive sensor 502 are insensitive to out-of-plane magnetic fields.

[0073] In summary, the magnetoresistive sensor 302 can have a first sensitivity axis, and the magnetic-free layer 306 can have a first magneto-free magnetization that is variable when a magnetic field in the plane, aligned with the first sensitivity axis, is present. The magnetoresistive sensor 502 can have a second sensitivity axis, and the magnetic-free layer 504 can have a second magneto-free magnetization that is variable when a magnetic field in the plane, aligned with the second sensitivity axis, is present. In some implementations, the first and second sensitivity axes are aligned with the same axis in the plane (e.g., an x-axis or a y-axis). In the implementation described in Fig. In the example shown in Figure 5, the first sensitivity axis and the second sensitivity axis are aligned with the x-axis.

[0074] The ferromagnetic disk 304 has a magnetic vortex configured to respond to an out-of-plane magnetic field (or an out-of-plane magnetic field component) and to generate a stray field when the out-of-plane magnetic field is applied to the ferromagnetic disk 304. The in-plane magnetic field component of the stray field can be aligned with the first sensitivity axis of the magnetoresistive sensor 302.

[0075] The magnetoresistive sensor 302 can be positioned within the stray field to receive the in-plane magnetic field component of the stray field, which is generated by the out-of-plane magnetic field. Thus, the magnetoresistive sensor 302 can be configured to change based on the in-plane magnetic field component of the stray field. However, since the magnetoresistive sensor 302 receives both the external magnetic field, which has its own in-plane magnetic field or its own in-plane magnetic field component, and the in-plane magnetic field component of the stray field, the magnetoresistive sensor 302 can respond to both the external magnetic field and the in-plane magnetic field component of the stray field.In the event that the magnetic-free magnetization of the magnetic-free layer 306 responds to both the external magnetic field and the in-plane magnetic field component of the stray field, the in-plane magnetic field component of the stray field would be indistinguishable from the in-plane magnetic field component of the external magnetic field when reading a sensor value from the magnetoresistive sensor 302. Consequently, the out-of-plane magnetic field (or an out-of-plane magnetic field component) of the external magnetic field would not be able to be measured based solely on the magnetoresistive sensor 302.

[0076] Since the stray field decays with increasing distance from the ferromagnetic disk 304, the magnetoresistive sensor 502 can be positioned at a sufficient distance from the ferromagnetic disk 304 so that it is located outside the stray field. In other words, the magnetoresistive sensor 502 can be positioned within the external magnetic field such that it responds to the in-plane component of the external magnetic field, but outside the stray field such that it does not respond to the in-plane component of the stray field. In other words, the magnetically free magnetization of the magnetically free layer 504 can respond only to the in-plane component of the external magnetic field.In some implementations, the magnetoresistive sensor 302 and the magnetoresistive sensor 502 can be arranged on the same lateral side of the ferromagnetic disk 304 at different lateral distances from the ferromagnetic disk 304.

[0077] The magnetoresistive sensor 302 has a first electrical resistance (or a first electrical conductivity) that changes based on changes in the magnetic free layer 306. The magnetoresistive sensor 502 has a second electrical resistance (or a second electrical conductivity) that changes based on changes in the magnetic free layer 504. The magnetic free layer 306 is configured to change based on the in-plane magnetic field component of the external magnetic field and the in-plane magnetic field component of the stray field such that the first electrical resistance has a first resistance component corresponding to the in-plane magnetic field component of the stray field and a second resistance component corresponding to the in-plane magnetic field component of the external magnetic field.The magnetically free layer 504 is designed to change solely on the basis of the in-plane magnetic field component of the external magnetic field such that the total resistance of the second electrical resistance corresponds to the in-plane magnetic field component of the external magnetic field.

[0078] The magnetic sensor system 500 further comprises a sensor circuit arrangement, similar to that found in conjunction with Fig. 1 describes a device configured to measure the first and second electrical resistances such that the second resistance component is negated by the second electrical resistance. For example, the sensor circuit arrangement can subtract the second electrical resistance from the first electrical resistance such that only the first resistance component of the first electrical resistance remains. In this way, a sensor reading corresponding only to the in-plane magnetic field component of the stray field can be separated from the influence of the in-plane magnetic field component of the external magnetic field.The sensor circuit arrangement can be configured to generate a sensor signal that represents only the first resistance component, which corresponds to the in-plane magnetic field component of the stray field and is proportional to the out-of-plane component of the external magnetic field.

[0079] In some implementations, the 500 magnetic sensor system can be used as a two-dimensional (2D) or three-dimensional (3D) sensor. The 302 magnetoresistive sensor can be referred to as an out-of-plane sensor or a z-sensor, since it is used to measure the out-of-plane component of the external magnetic field (e.g., Bz). The 502 magnetoresistive sensor can also be used to measure an in-plane component of the external magnetic field (e.g., Bx). In other words, the electrical resistance of the 502 magnetoresistive sensor can be used as a sensor value for the x-magnetic field component Bx of the external magnetic field when the sensor's sensitivity axis is aligned with the x-axis, or as a sensor value for the y-magnetic field component By when the sensor's sensitivity axis is aligned with the y-axis.The magnetoresistive sensor 502 can be referred to as an in-plane sensor, x-sensor or y-sensor, since the magnetoresistive sensor 502 is used to measure an in-plane component of the external magnetic field (e.g., Bx or By).

[0080] One or more magnetoresistive sensors can be added to measure a third dimension of the external magnetic field. For example, if the sensitivity axes of magnetoresistive sensor 302 and magnetoresistive sensor 502 are aligned with the x-axis, two additional magnetoresistive sensors with sensitivity axes aligned with the y-axis can be added. One of the additional magnetoresistive sensors, used as an out-of-plane sensor to measure Bz, can be located within the stray field, and the other of the additional magnetoresistive sensors, used as an in-plane sensor to measure By, can be located outside the stray field, similar to magnetoresistive sensors 302 and 502.In some implementations, only a magnetoresistive sensor located outside the stray field and having a sensitivity axis aligned with the y-axis can be added to measure the y-magnetic field component By of the external magnetic field.

[0081] As shown above, Fig. 5 is provided as an example. Other examples may differ from what is provided in relation to Fig. As described in section 5, the number and arrangement of in Fig. The five components shown are provided as an example. In practice, the magnetic sensor system may include 500 additional components, fewer components, different components, or components arranged differently than those shown. Fig. 5 are shown. Two or more components that are in Fig. The five shown can be implemented within a single component, or a single component that is in Fig. As shown in Figure 5, the system can be implemented as multiple, distributed components. Additionally or alternatively, a set of components (e.g., one or more components) of the magnetic sensor system 500 can perform one or more functions that are described as being performed by another set of components of the magnetic sensor system 500.

[0082] Fig. Figure 6 shows an example of a magnetic sensor system 600 according to one or more implementations. The magnetic sensor system 600 can be used to measure an external out-of-plane magnetic field (e.g., Bz) when an external in-plane magnetic field (e.g., Bx) is also present. The magnetic sensor system 600 can include the magnetoresistive sensor 302 and the ferromagnetic disk 304, as described in connection with the magnetic sensor system 300 of [reference missing]. Fig. 3 described. Additionally, the magnetic sensor system 600 can include an additional magnetoresistive sensor 602, which has a magnetically free layer 604 (e.g., a sensing layer) with a magnetically free magnetization (e.g., a magnetic vortex). The external magnetic field in one plane can be a homogeneous magnetic field extending through both the magnetoresistive sensor 302 and the magnetoresistive sensor 602.

[0083] The external out-of-plane magnetic field can be applied to the ferromagnetic disk 304, which has a magnetic vortex configured to respond to the out-of-plane magnetic field and, in response to the application of the external out-of-plane magnetic field to the ferromagnetic disk 304, to generate a stray field. The stray field has two lobes extending from the ferromagnetic disk 304 in opposite lateral directions. Both lobes are proportional to the external out-of-plane magnetic field due to a linear stray field response of the magnetic vortex of the ferromagnetic disk 304.

[0084] In particular, the stray field can have a first lobe 606 extending clockwise on the right side of the ferromagnetic disk 304 and a second lobe 608 extending counterclockwise on the left side of the ferromagnetic disk 304. The first lobe 606 comprises a first in-plane magnetic field component having a first vector in a first direction (e.g., a positive x-direction) aligned with a sensitivity axis of the magnetoresistive sensor 302. Furthermore, the first lobe 606 and the first in-plane magnetic field component are proportional to the external out-of-plane magnetic field. The second lobe 608 comprises a second in-plane magnetic field component having a second vector in a second direction (e.g., a negative x-direction) aligned with a sensitivity axis of the magnetoresistive sensor 602.Furthermore, the second lobe 608 and the second magnetic field component in the plane are proportional to the external magnetic field outside the plane. Thus, the first vector of the first magnetic field component in the plane is antiparallel to the second vector of the second magnetic field component in the plane.

[0085] The magnetoresistive sensor 302 and the magnetoresistive sensor 602 are located on opposite lateral sides of the ferromagnetic disk 304. For example, the magnetoresistive sensor 302 can be located within the first lobe 606 of the stray field at a location suitable for measuring the first magnetic field component in the plane, and the magnetoresistive sensor 602 can be located within the second lobe 608 of the stray field at a location suitable for measuring the second magnetic field component in the plane.

[0086] The magnetoresistive sensor 302 comprises a first sensitivity axis and a first magnetic-free layer 306 with a first magnetic-free magnetization that is variable in the presence of the external magnetic field in the plane and the first magnetic field component of the stray field lying in the plane, which is aligned with the first sensitivity axis. In other words, the first magnetic-free magnetization can respond to both the external magnetic field in the plane and the first magnetic field component of the stray field lying in the plane.

[0087] The magnetoresistive sensor 602 comprises a second sensitivity axis and a second magnetic-free layer 604 with a second magnetic-free magnetization that is variable in the presence of the external in-plane magnetic field and the second in-plane magnetic field component of the stray field, which is aligned with the second sensitivity axis. In other words, the second magnetic-free magnetization can respond to both the external in-plane magnetic field and the second in-plane magnetic field component of the stray field.

[0088] The first sensitivity axis of the magnetoresistive sensor 302 can be parallel to the second sensitivity axis of the magnetoresistive sensor 602, so that the magnetoresistive sensor 302 and the magnetoresistive sensor 602 are sensitive to the same magnetic field component in the plane and respond in the same way with respect to a magnetic field directed in the same direction (e.g., a positive x-direction). For example, if the external magnetic field in the plane is applied to both the magnetoresistive sensor 302 and the magnetoresistive sensor 602, the external magnetic field in the plane extends through both the magnetoresistive sensor 302 and the magnetoresistive sensor 602 in the same direction (e.g., a positive x-direction).The magnetoresistive sensor 302 and the magnetoresistive sensor 602 can be subjected to equal resistance changes due to the external magnetic field in the plane. Thus, the respective resistance changes of the magnetoresistive sensor 302 and the magnetoresistive sensor 602 resulting from the external magnetic field in the plane can be canceled out or negated during readout by the sensor circuit arrangement 610 (e.g., by subtraction or differential processing).

[0089] In contrast, the magnetoresistive sensor 302 and the magnetoresistive sensor 602 can be sensitive to the same in-plane magnetic field component, but respond in opposite ways to magnetic fields directed in opposite directions along the x-axis. Since the first in-plane magnetic field component and the second in-plane magnetic field component of the stray field are directed in opposite directions, the magnetoresistive sensor 302 and the magnetoresistive sensor 602 can each experience resistance changes due to the stray field that are equal but opposite in sign. When subtraction or differential processing is applied to the sensor signals of the magnetoresistive sensor 302 and the magnetoresistive sensor 602, the respective resistance changes due to the stray field can be summed (e.g., due to the subtraction of values ​​with opposite signs).Thus, the magnetoresistive sensor 302 is positioned within the first in-plane magnetic field component of the stray field to detect the first vector, and the magnetoresistive sensor 602 is positioned within the second in-plane magnetic field component of the stray field to detect the second vector. While both the magnetoresistive sensor 302 and the magnetoresistive sensor 602 can also respond to the external in-plane magnetic field, the resistance changes caused by the external in-plane magnetic field at the magnetoresistive sensor 302 and the magnetoresistive sensor 602 are canceled out by the sensor circuit arrangement 610.Meanwhile, the resistance changes caused at the magnetoresistive sensor 302 and at the magnetoresistive sensor 602 by the two antiparallel vectors of the stray field are summed to provide a delta resistance value that is proportional to the external out-of-plane magnetic field and is representative only of the same.

[0090] In summary, the magnetoresistive sensor 302 can exhibit a first electrical resistance that varies based on changes in the first magnetic free layer. This first electrical resistance can have a first resistance component corresponding to the first in-plane magnetic field component of the stray field and a second resistance component corresponding to the external in-plane magnetic field. The magnetoresistive sensor 602 can exhibit a second electrical resistance that changes based on changes in the second magnetic free layer. This second electrical resistance can have a third resistance component corresponding to the second in-plane magnetic field component of the stray field and a fourth resistance component corresponding to the external in-plane magnetic field.The sensor circuit arrangement 610 can be configured to measure the first electrical resistance and the second electrical resistance such that the second resistance component and the fourth resistance component are negated. Thus, the sensor circuit arrangement 610 can generate a sensor signal that represents a combined resistance of the first resistance component and the third resistance component, the combined resistance being proportional to the out-of-plane magnetic field.

[0091] As shown above, Fig. 6 is provided as an example. Other examples may differ from what is provided in relation to Fig. As described in section 6, the number and arrangement of in Fig. The six components shown are provided as an example. In practice, the magnetic sensor system may include 600 additional components, fewer components, different components, or components arranged differently than those shown. Fig. 6 are shown. Two or more components that are in Fig. The elements shown in 6 can be implemented within a single component, or a single component that is in Fig. As shown in Figure 6, the system can be implemented as multiple, distributed components. Additionally or alternatively, a set of components (e.g., one or more components) of the magnetic sensor system 600 can perform one or more functions that are described as being performed by another set of components of the magnetic sensor system 600.

[0092] The following is an overview of some aspects of the present revelation: Aspect 1: A magnetic sensor system comprising: a magnetoresistive sensor with a magnetic free layer having a sensing plane and a magnetic-free magnetization arranged within the sensing plane, wherein the magnetic-free magnetization is variable when a magnetic field is present in the plane aligned with the sensing plane;and a ferromagnetic disk with a magnetic vortex in a ground state, wherein the magnetic vortex is configured to respond to an out-of-plane magnetic field and, responding to the out-of-plane magnetic field being applied to the ferromagnetic disk, to generate a stray field, wherein the stray field has an in-plane magnetic field component proportional to the out-of-plane magnetic field, wherein the magnetic-free layer is configured to receive the in-plane magnetic field component of the stray field, and wherein the magnetic-free magnetization is configured to change based on the in-plane magnetic field component of the stray field. Aspect 2: The magnetic sensor system according to aspect 1, wherein the ferromagnetic disk is designed to convert the magnetic field outside the plane into the stray field with the magnetic field component in the plane. Aspect 3: The magnetic sensor system according to one of aspects 1-2, wherein the magnetic vortex provides a linear response to the out-of-plane magnetic field such that the in-plane magnetic field component of the stray field has a linear relationship to the out-of-plane magnetic field. Aspect 4: The magnetic sensor system according to one of aspects 1-3, wherein the ferromagnetic disk generates the in-plane magnetic field component of the stray field from the out-of-plane magnetic field based on a linear response function, and wherein the in-plane magnetic field component of the stray field has a linear relationship to the out-of-plane magnetic field based on the linear response function. Aspect 5: The magnetic sensor system according to Aspect 4, wherein an aspect ratio between a thickness and a diameter of the ferromagnetic disk defines a linear region section of the stray field, wherein the linear region section of the stray field responds to the out-of-plane magnetic field in a linear manner based on the linear response function, and wherein the magnetic free layer responds linearly to the linear region section of the stray field. Aspect 6: The magnetic sensor system according to one of aspects 1-5, wherein the ferromagnetic disk is configured to redirect the magnetic field outside the plane, as the stray field, into the detection plane of the magnetic free layer in such a way that the in-plane magnetic field component of the stray field is aligned in the plane with the detection plane of the magnetic free layer. Aspect 7: The magnetic sensor system according to one of aspects 1-6, wherein the magnetoresistive sensor is a linear magnetoresistive sensor with a linear sensor response. Aspect 8: The magnetic sensor system according to one of aspects 1-7, wherein the magnetic field outside the plane is orthogonal to the magnetic field component in the plane. Aspect 9: The magnetic sensor system according to one of aspects 1-8, wherein the magnetoresistive sensor is spatially separated from the ferromagnetic disk. Aspect 10: The magnetic sensor system according to one of aspects 1-9, wherein a magnetization of the ferromagnetic disk is a closed flux magnetization that is in a vortex state. Aspect 11: The magnetic sensor system according to any of Aspects 1-10, wherein the magnetoresistive sensor has an electrical conductivity or electrical resistance, and wherein the magnetoresistive sensor is configured to exhibit a linear change in electrical conductivity or electrical resistance proportional to the out-of-plane magnetic field based on a change in the free-magnetic magnetization responding to the in-plane magnetic field component of the stray field. Aspect 12: The magnetic sensor system according to one of aspects 1-11, wherein the magnetic vortex is generated within the ferromagnetic disk based on a volume of the ferromagnetic disk, and wherein a linear stray field response of the magnetic vortex is defined by an aspect ratio of the ferromagnetic disk. Aspect 13: The magnetic sensor system according to one of aspects 1-12, wherein the ferromagnetic disk is configured to not generate a measurable stray field at the magnetoresistive sensor when no external magnetic field or an insignificant external magnetic field is applied to the ferromagnetic disk. Aspect 14: The magnetic sensor system according to one of aspects 1-13, wherein the ferromagnetic disk is made of a soft ferromagnetic material. Aspect 15: A magnetic sensor system comprising: a first magnetoresistive sensor with a first sensitivity axis and a first magnetic-free layer with a first magnetic-free magnetization that is variable in the presence of an in-plane magnetic field aligned with the first sensitivity axis; a second magnetoresistive sensor with a second sensitivity axis and a second magnetic-free layer with a second magnetic-free magnetization that is variable in the presence of the in-plane magnetic field aligned with the second sensitivity axis; and a ferromagnetic disk with a magnetic vortex in a ground state, wherein the magnetic vortex is configured to respond to an out-of-plane magnetic field and to generate a stray field in response to the out-of-plane magnetic field being applied to the ferromagnetic disk.wherein the stray field decays with increasing distance from the ferromagnetic disk, wherein the first magnetoresistive sensor is arranged within the stray field and the second magnetoresistive sensor is arranged outside the stray field, wherein the stray field has an in-plane magnetic field component proportional to the out-of-plane magnetic field, wherein the first magnetic-free layer is configured to receive the in-plane magnetic field component of the stray field, and wherein the first magnetic-free magnetization is configured to change based on the in-plane magnetic field component of the stray field. Aspect 16: The magnetic sensor system according to Aspect 15, wherein the first magnetoresistive sensor has a first electrical resistance that changes based on changes in the first magnetic free layer, wherein the second magnetoresistive sensor has a second electrical resistance that changes based on changes in the second magnetic free layer, wherein the first magnetic free layer is configured to change based on the stray field and the magnetic field in the plane such that the first electrical resistance has a first resistance component corresponding to the in-plane magnetic field component of the stray field and a second resistance component corresponding to the magnetic field in the plane, wherein the second magnetic free layer is configured to change based on the magnetic field in the plane such thatthat a total resistance of the second electrical resistance corresponds to the magnetic field in the plane, wherein the magnetic sensor system further comprises a sensor circuit configured to measure the first electrical resistance and the second electrical resistance such that the second resistance component is negated by the second electrical resistance, and wherein the sensor circuit is configured to generate a sensor signal representing the first resistance component corresponding to the magnetic field component of the stray field lying in the plane. Aspect 17: The magnetic sensor system according to one of aspects 15-16, wherein the first magnetoresistive sensor and the second magnetoresistive sensor are arranged on the same lateral side of the ferromagnetic disk. Aspect 18: A magnetic sensor system comprising: a ferromagnetic disk with a magnetic vortex in a ground state, wherein the magnetic vortex is configured to respond to an out-of-plane magnetic field and, responding to the out-of-plane magnetic field being applied to the ferromagnetic disk, to generate a stray field, wherein the stray field has a first in-plane magnetic field component and a second in-plane magnetic field component proportional to the out-of-plane magnetic field, and wherein the first in-plane magnetic field component has a first vector in a first direction and the second in-plane magnetic field component has a second vector in a second direction antiparallel to the first direction;a first magnetoresistive sensor with a first sensitivity axis and a first magnetic free layer with a first magnetic-free magnetization that is variable in the presence of an external magnetic field in the plane aligned with the first sensitivity axis;and a second magnetoresistive sensor with a second sensitivity axis and a second magnetic free layer with a second magnetic-free magnetization which is variable in the presence of the external magnetic field in the plane which is aligned with the second sensitivity axis, wherein the first sensitivity axis is parallel to the second sensitivity axis, wherein the first magnetoresistive sensor is arranged within the first in-plane magnetic field component of the stray field in order to detect the first vector, and wherein the second magnetoresistive sensor is arranged within the second in-plane magnetic field component of the stray field in order to detect the second vector. Aspect 19: The magnetic sensor system according to Aspect 18, wherein the first magnetoresistive sensor and the second magnetoresistive sensor are located on opposite lateral sides of the ferromagnetic disk. Aspect 20: The magnetic sensor system according to one of aspects 18-19, wherein the external magnetic field in the plane is a homogeneous magnetic field extending through both the first magnetoresistive sensor and the second magnetoresistive sensor either in the first direction or in the second direction, wherein the first magnetoresistive magnetization is configured to change based on the first in-plane magnetic field component of the stray field and the external magnetic field in the plane, and wherein the second magnetoresistive magnetization is configured to change based on the second in-plane magnetic field component of the stray field and the external magnetic field in the plane. Aspect 21: The magnetic sensor system according to any of Aspects 18 to 20, wherein the first magnetoresistive sensor has a first electrical resistance which varies based on changes in the first magnetic free layer, wherein the first electrical resistance has a first resistance component corresponding to the first in-plane magnetic field component of the stray field, and a second resistance component corresponding to the external in-plane magnetic field, wherein the second magnetoresistive sensor has a second electrical resistance which varies based on changes in the second magnetic free layer, wherein the second electrical resistance has a third resistance component corresponding to the second in-plane magnetic field component of the stray field, and a fourth resistance component corresponding to the external in-plane magnetic field, wherein the magnetic sensor system further comprises a sensor circuit,which is configured to measure the first electrical resistance and the second electrical resistance such that the second resistance component and the fourth resistance component are negated, wherein the sensor circuit is configured to generate a sensor signal representing a combined resistance of the first resistance component and the third resistance component, and wherein the combined resistance is proportional to the out-of-plane magnetic field. Aspect 22: A system that is trained to perform one or more of the operations mentioned in one or more of Aspects 1-21. Aspect 23: A device comprising means for performing one or more of the operations mentioned in one or more of Aspects 1-21. Aspect 24: A non-volatile, computer-readable medium that stores a set of instructions, wherein the set of instructions comprises one or more instructions which, when executed by a device, cause the device to perform one or more operations specified in one or more of Aspects 1-21. Aspect 25: A computer program product comprising instructions or code for performing one or more of the operations mentioned in one or more of Aspects 1-21.

[0093] The foregoing disclosure provides an illustration and description, but is not intended to be exhaustive or to limit the implementations to the specific form disclosed. Modifications and variations may be made taking into account the above disclosure or may be derived from the practical application of the implementations.

[0094] Some implementations may be described herein in connection with thresholds. As used herein, "meeting" a threshold may refer to a value that is greater than the threshold, more than the threshold, higher than the threshold, greater than or equal to the threshold, less than the threshold, less than the threshold, lower than the threshold, less than or equal to the threshold, equal to the threshold, or similar.

[0095] As used herein, the term "component" is to be understood in its broadest sense as hardware, firmware, or a combination of hardware and software. It is evident that systems and / or procedures described herein may be implemented in various forms of hardware, firmware, or a combination of hardware and software. The actual specialized control hardware or software code used to implement these systems and / or procedures is not limiting to the implementations. The operation and behavior of the systems and / or procedures are thus described herein without reference to any specific software code—it being assumed that software and hardware may be designed to implement the systems and / or procedures based on the description herein.

[0096] Any of the processing components can be implemented as a central processing unit (CPU) or another processor that reads or executes a software program from a non-volatile, computer-readable recording medium, such as a hard disk or a semiconductor memory device. For example, instructions can be executed by one or more processors, such as one or more CPUs, digital signal processors (DSPs), general-purpose microprocessors, application-specific integrated circuits (ASICs), field-programmable logic arrays (FPGAs), programmable logic controllers (PLCs), or any other equivalent integrated or discrete logic circuit arrangement.Accordingly, as used herein, the term "processor" refers to any of the preceding structures or any other structure suitable for implementing the techniques described herein. Software may be stored on a non-volatile, computer-readable medium such that the non-volatile, computer-readable medium comprises program code or a program algorithm stored thereon which, when executed, causes the processor, via a computer program, to perform the steps of a procedure.

[0097] A controller comprising hardware may also execute one or more of the techniques of this disclosure. A controller comprising one or more processors may use electrical signals and digital algorithms to perform its receptive, analytical, and control functions, which may further include corrective functions. Such hardware, software, and firmware may be implemented within the same device or within separate devices to support the various techniques described in this disclosure.

[0098] A signal processing circuit and / or a signal conditioning circuit can receive one or more signals (e.g., measurement signals) from one or more components in the form of raw measurement data and can derive further information from the measurement signal. "Signal conditioning," as used here, refers to manipulating an analog signal in such a way that the signal meets the requirements of a subsequent processing stage. Signal conditioning can include analog-to-digital conversion (e.g., via an analog-to-digital converter), amplification, filtering, conversion, biasing, range matching, isolation, and any other processes necessary to make a signal suitable for processing after conditioning.

[0099] Although certain combinations of features are reproduced in the claims and / or disclosed in the description, these combinations are not intended to limit the disclosure of implementations described herein. Many of these features can be combined in ways not specifically reproduced in the claims and / or disclosed in the description. For example, the disclosure includes each dependent claim in a set of claims in combination with each other individual claim in that set of claims and any combination of several claims in that set of claims. In our usage, an expression referring to "at least one of" a list of elements refers to any combination of those elements, comprising individual parts. For example, "at least one of: a, b, or c" is intended to cover a, b, c, a and b, a and c, b and c, and a, b, and c, as well as any combination with multiples of the same element (e.g.,a + a, a + a + a, a + a + b, a + a + c, a + b + b, a + c + c, b + b, b + b + b, b + b + c, c + c and c + c + c or any other order of a, b and c).

[0100] Furthermore, it is understood that the disclosure of several steps or functions revealed in the description or claims may not be intended to be interpreted as being in a specific order. Therefore, the disclosure of multiple steps or functions does not restrict them to a specific order unless these steps or functions are not interchangeable for technical reasons. Furthermore, in some implementations, a single step may comprise several substeps or may be divided into several substeps. Such substeps may be included and form part of the disclosure of that single step unless they are explicitly excluded.

[0101] No element, step, or instruction used herein shall be construed as decisive or essential unless explicitly described as such. Furthermore, according to usage herein, the articles "ein, eine" shall encompass one or more elements and may be used synonymously with "ein oder mehr." Furthermore, according to usage herein, the article "der, die, das" shall encompass one or more elements referred to in conjunction with the article "der, die, das" and may be used synonymously with "dem / der einen oder den mehr." In cases where only one element is intended, the phrase "nur ein," "einzelne,r,s," or similar language shall be used. Furthermore, according to usage herein, the terms "aufweist," "aufweisen," "aufweisend," or similar shall be open terms that do not restrict an element they modify (e.g., an element that "aufweisen" A may also "aufweisen" B).Furthermore, the phrase "based on" shall mean "based, at least in part, on" unless expressly stated otherwise. According to local usage, the term "several" may be replaced by "a multitude of" and vice versa. Similarly, according to local usage, the term "or" shall be comprehensive when used in a series and may be used interchangeably with "and / or" unless expressly stated otherwise (e.g., when used in combination with "either" or "only one of").

Claims

[1] A magnetic sensor system comprising: a magnetoresistive sensor comprising a magnetic free layer having a sensing plane and a magnetic-free magnetization disposed within the sensing plane, the magnetic-free magnetization being variable in the presence of an in-plane magnetic field aligned with the sensing plane; and a ferromagnetic disc having a magnetic vortex in a ground state, the magnetic vortex being configured to respond to an out-of-plane magnetic field and to generate a stray field in response to the out-of-plane magnetic field being applied to the ferromagnetic disc, wherein the stray field has an in-plane magnetic field component that is proportional to the out-of-plane magnetic field, wherein the magnetic free layer is designed to receive the in-plane magnetic field component of the stray field, and wherein the magnetic-free magnetization is configured to change based on the in-plane magnetic field component of the stray field. [2] The magnetic sensor system according to claim 1, wherein the ferromagnetic disk is configured to convert the out-of-plane magnetic field into the stray field with the in-plane magnetic field component. [3] The magnetic sensor system of claim 1 or 2, wherein the magnetic vortex provides a linear response to the out-of-plane magnetic field such that the in-plane magnetic field component of the stray field has a linear relationship to the out-of-plane magnetic field. [4] The magnetic sensor system according to any one of the preceding claims, wherein the ferromagnetic disk generates the in-plane magnetic field component of the stray field from the out-of-plane magnetic field based on a linear response function, and wherein the in-plane magnetic field component of the stray field has a linear relationship with the out-of-plane magnetic field based on the linear response function. [5] The magnetic sensor system according to claim 4, wherein an aspect ratio between a thickness and a diameter of the ferromagnetic disk defines a linear range portion of the stray field, wherein the linear region portion of the stray field responds to the out-of-plane magnetic field in a linear manner based on the linear response function, and wherein the magnetic free layer responds in a linear manner to the linear region portion of the stray field. [6] The magnetic sensor system according to any one of the preceding claims, wherein the ferromagnetic disk is configured to redirect the out-of-plane magnetic field, as the stray field, into the sensing plane of the magnetic free layer such that the in-plane magnetic field component of the stray field is aligned in-plane with the sensing plane of the magnetic free layer. [7] The magnetic sensor system according to any one of the preceding claims, wherein the magnetoresistive sensor is a linear magnetoresistive sensor having a linear sensor response. [8] The magnetic sensor system according to any one of the preceding claims, wherein the out-of-plane magnetic field is orthogonal to the in-plane magnetic field component. [9] The magnetic sensor system according to any one of the preceding claims, wherein the magnetoresistive sensor is spatially separated from the ferromagnetic disk. [10] The magnetic sensor system according to any one of the preceding claims, wherein a magnetization of the ferromagnetic disk is a closed flux magnetization that is in a vortex state. [11] The magnetic sensor system according to any one of the preceding claims, wherein the magnetoresistive sensor has an electrical conductivity or an electrical resistance, and wherein the magnetoresistive sensor is configured to have a linear change in electrical conductivity or electrical resistance proportional to the out-of-plane magnetic field based on a change in magnetic-free magnetization responsive to the in-plane magnetic field component of the stray field. [12] The magnetic sensor system according to any one of the preceding claims, wherein the magnetic vortex is generated within the ferromagnetic disk based on a volume of the ferromagnetic disk, and wherein a linear stray field response of the magnetic vortex is defined by an aspect ratio of the ferromagnetic disk. [13] The magnetic sensor system according to any one of the preceding claims, wherein the ferromagnetic disc is configured not to generate a measurable stray field at the magnetoresistive sensor when no external magnetic field or an insignificant external magnetic field is applied to the ferromagnetic disc. [14] The magnetic sensor system according to any one of the preceding claims, wherein the ferromagnetic disc is made of a soft ferromagnetic material. [15] A magnetic sensor system comprising: a first magnetoresistive sensor having a first sensitivity axis and a first magnetic free layer having a first magnetic-free magnetization that is variable in the presence of an in-plane magnetic field aligned with the first sensitivity axis; a second magnetoresistive sensor having a second sensitivity axis and a second magnetic free layer having a second magnetic-free magnetization that is variable in the presence of the in-plane magnetic field aligned with the second sensitivity axis; and a ferromagnetic disc having a magnetic vortex in a ground state, the magnetic vortex being configured to respond to an out-of-plane magnetic field and to generate a stray field in response to the out-of-plane magnetic field being applied to the ferromagnetic disc, the stray field decaying with increasing distance from the ferromagnetic disc, wherein the first magnetoresistive sensor is arranged within the stray field and the second magnetoresistive sensor is arranged outside the stray field, wherein the stray field has an in-plane magnetic field component that is proportional to the out-of-plane magnetic field, wherein the first magnetic free layer is designed to receive the in-plane magnetic field component of the stray field, and wherein the first magnetic-free magnetization is configured to change based on the in-plane magnetic field component of the stray field. [16] The magnetic sensor system according to claim 15, wherein the first magnetoresistive sensor has a first electrical resistance that changes based on changes in the first magnetic free layer, wherein the second magnetoresistive sensor has a second electrical resistance that changes based on changes in the second magnetic free layer, wherein the first magnetic free layer is configured to change based on the stray field and the in-plane magnetic field such that the first electrical resistance has a first resistance component corresponding to the in-plane magnetic field component of the stray field and a second resistance component corresponding to the in-plane magnetic field, wherein the second magnetic free layer is configured to change based on the in-plane magnetic field such that a total resistance of the second electrical resistance corresponds to the in-plane magnetic field, wherein the magnetic sensor system further comprises a sensor circuit configured to measure the first electrical resistance and the second electrical resistance such that the second resistance component is negated by the second electrical resistance, and wherein the sensor circuit is configured to generate a sensor signal representing the first resistance component corresponding to the in-plane magnetic field component of the stray field. [17] The magnetic sensor system according to claim 15 or 16, wherein the first magnetoresistive sensor and the second magnetoresistive sensor are arranged on a same lateral side of the ferromagnetic disk. [18] A magnetic sensor system comprising: a ferromagnetic disk having a magnetic vortex in a ground state, the magnetic vortex being configured to respond to an out-of-plane magnetic field and to generate a stray field in response to the out-of-plane magnetic field being applied to the ferromagnetic disk, the stray field comprising a first in-plane magnetic field component and a second in-plane magnetic field component proportional to the out-of-plane magnetic field, the first in-plane magnetic field component comprising a first vector in a first direction and the second in-plane magnetic field component comprising a second vector in a second direction antiparallel to the first direction; a first magnetoresistive sensor having a first sensitivity axis and a first magnetic free layer having a first magnetic-free magnetization that is variable in the presence of an external in-plane magnetic field aligned with the first sensitivity axis; and a second magnetoresistive sensor having a second sensitivity axis and a second magnetic free layer having a second magnetic-free magnetization that is variable in the presence of the external magnetic field in the plane aligned with the second sensitivity axis, wherein the first sensitivity axis is parallel to the second sensitivity axis, wherein the first magnetoresistive sensor is arranged within the first in-plane magnetic field component of the stray field to detect the first vector, and wherein the second magnetoresistive sensor is arranged within the second in-plane magnetic field component of the stray field to detect the second vector. [19] The magnetic sensor system of claim 18, wherein the first magnetoresistive sensor and the second magnetoresistive sensor are located on opposite lateral sides of the ferromagnetic disk. [20] The magnetic sensor system according to claim 18 or 19, wherein the external in-plane magnetic field is a homogeneous magnetic field extending through both the first magnetoresistive sensor and the second magnetoresistive sensor in either the first direction or the second direction, wherein the first magnetic-free magnetization is configured to change based on the first in-plane magnetic field component of the stray field and the external in-plane magnetic field, and wherein the second magnetic-free magnetization is configured to change based on the second in-plane magnetic field component of the stray field and the external in-plane magnetic field.

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