MAGNETIC FIELD SENSOR AND MAGNETIC FIELD DETECTION METHOD

Abstract

A magnetic field sensor (300; 500), comprising: at least one magnetic field sensor element (302; 502) configured to generate a first sensor signal (304) responding to a magnetic field (306; 506); at least one Hall sensor element (308; 508) configured to generate a second sensor signal (310) responding to the magnetic field (306; 506), wherein the Hall sensor element (308; 508) is a vertical Hall sensor element and is configured to generate the second sensor signal (310) responding to a magnetic field (306; 506) parallel to an upper surface of the magnetic field sensor element and / or parallel to an upper surface of the vertical Hall sensor element; a compensation logic (312) configured to compensate one of the first and the second sensor signals using the other sensor signal.

Description

Area

[0001] The present disclosure relates to sensor components and in particular to magnetic field sensor components. background

[0002] Today, cars feature numerous safety, body, and powertrain applications that rely on magnetic position and / or angle sensors. For example, electric power steering (EPS) systems can use magnetic angle sensors and linear Hall sensors to measure steering angle and torque. Modern powertrain systems may rely on magnetic speed sensors for camshaft, crankshaft, and transmission applications, along with automotive pressure sensors, to meet CO2 emissions targets and implement intelligent powertrain solutions.

[0003] Magnetic sensors include, for example, magnetoresistive sensors and Hall-effect sensors (Hall sensors). Magnetoresistance is a property of a material to change the value of its electrical resistance when an external magnetic field is applied to it.Some examples of magnetoresistive effects are giant magneto-resistance (GMR), a quantum mechanical magnetoresistive effect observed in thin-film structures composed of alternating ferromagnetic and non-magnetic conductive layers; tunnel magneto-resistance (TMR), a magnetoresistive effect occurring at a magnetic tunnel junction (MTJ), which is a component consisting of two ferromagnets separated by a thin insulator; or anisotropic magneto-resistance (AMR), a property of a material in which the electrical resistance depends on the angle between the direction of the electric current and the direction of the magnetization.The majority of different magnetoresistive effects are commonly abbreviated as xMR, where "x" acts as a placeholder for the various magnetoresistive effects. xMR sensors can detect the orientation of an applied magnetic field by measuring sine and cosine angular components using monolithically integrated magnetoresistive sensor elements.

[0004] Such xMR sensors are known, for example, from the German patent applications DE 10 2006 022 336 A1 or DE 10 2014 115 113 A1. There, lateral Hall sensors or xMR sensors with varying accuracy are used for fault detection and correction.

[0005] A Hall effect sensor is a transducer that varies its output voltage (Hall voltage) in response to a magnetic field. It is based on the Hall effect, which utilizes the Lorentz force. The Lorentz force deflects moving charges in the presence of a magnetic field perpendicular to the current flow through the sensor or the Hall plate. A Hall plate can be a thin piece of semiconductor or metal. This deflection causes charge separation, which generates an electric Hall field. This electric field acts on the charge in the opposite direction to the Lorentz force. The two forces balance each other, creating a potential difference perpendicular to the direction of current flow. This potential difference can be measured as a Hall voltage and varies linearly with the magnetic field for small values.Hall effect sensors can be used for proximity switching, positioning, speed detection and current sensing applications.

[0006] Currently, the accuracy of magnetic angle sensors is limited by the accuracy of the sensing element itself, even with ideal calibration. This angular error is not constant at every angle but varies across the entire angular range. It is possible to use lookup tables (LUTs) for further compensation. These tables store the characteristics of the angular error across the angular range and compensate for it in the output value. However, some disadvantages of using a LUT include: - The LUT must be created by the user and stored in their microcontroller or chip EEPROM (Electrically Erasable Programmable Read-Only Memory; EEPROM = Electrically Erasable Programmable Read-Only Memory). - The data in the LUT is static and does not cover temperature and lifetime drifts, which changes the characteristics of the angular error.

[0007] It is therefore desirable to provide improved magnetic sensors, taking into account the problems mentioned above. Summary

[0008] According to a first aspect, the present disclosure provides a magnetic field sensor. The magnetic field sensor comprises at least one magnetic field sensor element configured to generate a first sensor signal in response to a magnetic field. The magnetic field sensor further comprises at least one Hall sensor element configured to generate a second sensor signal in response to the (same) magnetic field. A compensation logic associated with the magnetic field sensor is configured to compensate for one of the first and the second sensor signals using the respective other sensor signal.

[0009] In some embodiments, the magnetic field sensor element is configured to generate the first sensor signal in response to a magnetic field parallel to an upper surface of the magnetic field sensor element. The magnetic field sensor element can be implemented in a semiconductor chip. Thus, the magnetic field sensor element can be configured to generate the first sensor signal in response to a magnetic field parallel to an upper surface of the semiconductor chip.

[0010] In some embodiments, the magnetic field sensor element comprises a magnetoresistive sensor element, i.e., an xMR sensor element.

[0011] In some embodiments, the magnetoresistive sensor element can be a giant magnetoresistive (GMR) sensor element, a tunnel magnetoresistive (TMR) sensor element, or an anisotropic magnetoresistive (AMR) sensor element, to name just a few magnetoresistive effects.

[0012] In some embodiments, the Hall sensor element is a vertical Hall sensor element and is thus configured to generate the second sensor signal in response to a magnetic field parallel to the upper surface of the magnetic field sensor element and / or parallel to an upper surface of the vertical Hall sensor element. The vertical Hall sensor element can be implemented in a semiconductor chip. Thus, the vertical Hall sensor element can be configured to generate the second sensor signal in response to a magnetic field parallel to an upper surface of the semiconductor chip.

[0013] In some embodiments, the Hall sensor element is installed with a fixed, predefined orientation relative to a reference direction of the magnetic field sensor element and is configured for current flow along this predefined orientation. In other words, the orientation of the current flow can be considered an indicator of the orientation of the Hall sensor element. Similarly, the orientation of the Hall sensor element can also be related to its minimum or maximum magnetic sensitivity (e.g., mV / Gauss). For example, the sensitivity of the Hall sensor element is minimal for external magnetic fields oriented parallel or antiparallel to the current flow orientation. Likewise, the sensitivity of the Hall sensor element is maximal for external magnetic fields oriented perpendicular to the current flow orientation.

[0014] In some embodiments, compensation logic is implemented to correct the first sensor signal, which indicates the magnetic field, based on the second sensor signal, which indicates the (same) magnetic field. In other words, the second sensor signal can be used to correct inaccuracies in the first sensor signal.

[0015] In some embodiments, the compensation logic is designed to apply a correction to the first sensor signal, at least if the second sensor signal indicates an orientation of the magnetic field parallel or perpendicular to an orientation of the Hall sensor element and if the first sensor signal indicates a different orientation of the magnetic field.

[0016] In some embodiments, the magnetic field sensor comprises a first Hall sensor element installed in a first orientation with respect to the magnetic field sensor element and configured to generate a first Hall sensor signal responding to the magnetic field, and at least a second Hall sensor element installed in a second orientation with respect to the magnetic field sensor element and configured to generate a second Hall sensor signal responding to the magnetic field, wherein the compensation logic is configured to compensate the first sensor signal based on the first and / or the second Hall sensor signal.

[0017] In some embodiments, at least one magnetic field sensor element and at least one Hall sensor element are integrated into the same semiconductor package. They can be implemented on different semiconductor chips.

[0018] In some embodiments, at least one magnetic field sensor element and at least one Hall sensor element are integrated on the same semiconductor chip.

[0019] According to another aspect of the present disclosure, a magnetic angle sensor is provided, comprising a magnetoresistive angle sensor element configured to generate an angle sensor signal responding to a magnetic field acting on the magnetoresistive angle sensor element, a first Hall sensor element installed in a first orientation with respect to the magnetoresistive angle sensor element and configured to generate a first Hall sensor signal responding to the magnetic field, at least a second Hall sensor element installed in a second orientation with respect to the magnetoresistive angle sensor element and configured to generate a second Hall sensor signal responding to the magnetic field, and a compensation processor configured to correct the angle sensor signal based on the first and / or the second Hall sensor signal.

[0020] In some embodiments, the compensation processor is designed to correct the angle sensor signal, at least when the first Hall sensor signal indicates an orientation of the magnetic field parallel or perpendicular to the first orientation and when the angle sensor signal indicates a different orientation of the magnetic field, or when the second Hall sensor signal indicates an orientation of the magnetic field parallel or perpendicular to the second orientation and when the angle sensor signal indicates a different orientation of the magnetic field.

[0021] In some embodiments, the magnetoresistive angle sensor element, the first and the second Hall sensor element are integrated in the same semiconductor package or on the same semiconductor chip.

[0022] According to a further aspect of the present disclosure, a magnetic angle sensor device is provided, comprising a magnetic angle sensor element configured to generate an angle sensor signal in response to a magnetic field applied to the magnetic angle sensor element. The device further comprises a first magnetoresistive sensor element having a first predefined magnetic orientation of its hard magnetic layer relative to the magnetic angle sensor element and configured to generate a first reference sensor signal in response to the magnetic field. At least one second magnetoresistive sensor element of the device has a second predefined magnetic orientation of its hard magnetic layer relative to the magnetic angle sensor element and is configured to generate a second reference sensor signal in response to the magnetic field.A processor is designed to correct the angle sensor signal based on the first and / or the second reference sensor signal.

[0023] In some embodiments, the processor is configured to correct the angle sensor signal, at least when the first reference sensor signal indicates an orientation of the magnetic field parallel or perpendicular to the first magnetic orientation and when the angle sensor signal indicates a different orientation of the magnetic field, or when the second reference sensor signal indicates an orientation of the magnetic field parallel or perpendicular to the second magnetic orientation and when the angle sensor signal indicates a different orientation of the magnetic field.

[0024] In some embodiments, the magnetic angle sensor element, the first magnetoresistive sensor element and the second magnetoresistive sensor element are integrated on a common semiconductor chip.

[0025] According to a further aspect of the present disclosure, a magnetic field detection method is provided. The method comprises measuring a magnetic field using a magnetic field sensor element, measuring the magnetic field using at least one Hall sensor element with a predetermined orientation relative to the magnetic field sensor element, and correcting the measurement of the magnetic field sensor element based on the measurement of the at least one Hall sensor element.

[0026] In some embodiments, the measurement of the magnetic field sensor element is corrected, at least if the measurement of the Hall sensor element indicates an orientation of the magnetic field parallel or perpendicular to the predetermined orientation of the Hall sensor element, and if the measurement of the magnetic field sensor element indicates a different orientation of the magnetic field.

[0027] In some embodiments, measuring the magnetic field using at least one Hall sensor element comprises measuring the magnetic field using a first Hall sensor element with a first orientation with respect to the magnetic field sensor element and measuring the magnetic field using at least one second Hall sensor element with a second orientation with respect to the magnetic field sensor element.

[0028] In some embodiments, the measurement of the magnetic field sensor element is corrected, at least if the measurement of the first Hall sensor element indicates an orientation of the magnetic field parallel or perpendicular to the first orientation and if the measurement of the magnetic field sensor element indicates a different orientation of the magnetic field, and / or if the measurement of the second Hall sensor element indicates an orientation of the magnetic field parallel or perpendicular to the second orientation and if the measurement of the magnetic field sensor element indicates a different orientation of the magnetic field.

[0029] For intermediate orientations of the magnetic field between the first and second orientation, the measurement of the magnetic field sensor element can be corrected using interpolated error values ​​derived from the measurement errors at the first and second orientations. Brief description of the characters

[0030] Some exemplary embodiments of devices and / or methods are described below only by way of example and with reference to the accompanying figures, in which paragraph Fig. Figures 1a-c show different examples of implementations of GMR sensor elements; Fig. 2 shows an exemplary embodiment of an implementation of a TMR sensor element; Fig. Figure 3 shows a schematic view of an embodiment of a magnetic field sensor; Fig. 4 shows a working principle of a vertical Hall sensor; Fig. 5a-c describe the operating principle of a magnetic angle sensor according to an example; Fig. 6a-c illustrate a working principle of a magnetic angle sensor according to another example. Fig. Figures 7a and b show exemplary compensation curves; and Fig. Figure 8 shows a flowchart of a magnetic field detection method according to the present disclosure. Detailed description

[0031] Various embodiments will now be described in more detail with reference to the accompanying drawings, in which some embodiments are illustrated.

[0032] While various modifications and alternative forms of embodiments are possible, examples are shown in the drawings and described in detail here. It is understood, however, that the intention is not to limit embodiments to the specific forms disclosed, but rather that the embodiments should encompass all modifications, equivalents, and alternatives falling within the scope of the disclosure. Throughout the description of the figures, identical numbers refer to identical elements.

[0033] It is understood that when an element is described as "connected" or "coupled" to another element, it may be directly connected or coupled to the other element, or there may be intermediate elements. Conversely, when an element is described as "directly" "connected" or "coupled" to another element, there are no intermediate elements. Other words used to describe the relationship between elements should be interpreted similarly (e.g., "between" versus "directly between," "adjacent" versus "directly adjacent," etc.).

[0034] The terminology used here is intended only to describe specific embodiments and is not meant to be limiting to further embodiments. According to our usage, the single forms "ein, eine" and "das, der, die" are also to include the plural forms unless the context clearly indicates otherwise. Furthermore, it is understood that the terms "umfassungt," "umfassend," "aufweisen," and / or "aufweisend," as used here, indicate the presence of specified features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0035] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as they would normally be understood by a person of average competence in the field to which the examples relate. Furthermore, it is understood that terms, e.g., those defined in commonly used dictionaries, should be interpreted as having a meaning unless expressly defined otherwise.

[0036] The principles of this disclosure can be applied to a variety of magnetic field sensors, including, for example, microelectromechanical sensors (MEMS sensors; MEMS = microelectromechanical), Hall sensors, or magnetoresistive sensors. Magnetoresistive sensors include GMR sensors, TMR sensors, AMR sensors, and various other current and future sensors based on magnetoresistance.

[0037] The following briefly explains some examples of GMR structure implementations. GMR structures are often operated in a so-called CIP configuration (current-in-plane), meaning the applied current flows parallel to the layer structure or the top surface of the chip. Several basic types of GMR structures exist and are predominant in practice. Some examples of GMR structures are described in Fig. 1a-c shown.

[0038] The in Fig. Figure 1a illustrates an embodiment of a GMR structure, showing a coupled GMR system 100 in which two magnetic layers 102, 106, e.g. made of cobalt (Co), are separated by a non-magnetic layer 104, e.g. made of copper (Cu). The thickness of the non-magnetic layer 104 can be selected such that, without an external magnetic field being applied, an anti-ferromagnetic coupling of the soft magnetic layers 102, 106 is established. This is indicated by the arrows. An external magnetic field can then induce the parallel alignment of the magnetization of the soft magnetic layers 102, 106, thereby reducing the resistance of the GMR structure.

[0039] The in Fig. Figure 1b shows an embodiment of a spin valve system 101 in which the non-magnetic layer 104 is selected with a thickness such that no coupling occurs between the soft magnetic layers 102 and 106. The lower magnetic layer 106 is strongly coupled to an anti-ferromagnetic layer 108, making it hard magnetic (comparable to a permanent magnet). The upper magnetic layer 102 is soft magnetic and serves as a sensing layer. It can be magnetized by a small external magnetic field M, which changes the resistance value R.

[0040] The following is the in Fig. The spin valve arrangement 101 shown in Figure 1b is explained in more detail. Such a spin valve structure 101 comprises a soft magnetic layer 102, which is separated by a non-magnetic layer 104 from a second soft magnetic layer 106, the magnetization direction of which, however, is determined by coupling with an antiferromagnetic layer 108 via the so-called "exchange bias interaction". The basic functioning of a spin valve structure can be explained using the magnetization and R(H) curve in Figure 1b. Fig. Figure 1b illustrates this. The magnetization direction of the magnetic layer 106 is fixed in the negative direction. When the external magnetic field M is increased from negative to positive values, the "free" soft magnetic layer 102 switches near the zero transition (H=0), and the resistance value R increases sharply. The resistance value R then remains high until the external magnetic field M is large enough to overcome the exchange coupling between the soft magnetic layer and the antiferromagnetic layer 108 and also switch the magnetic layer 106.

[0041] The in Fig. The embodiment of the GMR structure 101 shown in 1c differs from the one in Fig. The GMR structure shown in Figure 1b is modified in that the lower antiferromagnetic layer 108 is replaced by a combination of a natural antiferromagnet 110 and a synthetic antiferromagnet 106, 107, 109 (SAF; SAF = synthetic antiferromagnet), which is located on top of it and comprises the magnetic layer 106, a ferromagnetic layer 107, and a non-magnetic intermediate layer 109. In this way, the magnetization direction of the magnetic layer 106 is fixed. The upper soft magnetic layer 102 again serves as a measuring layer, the magnetization direction of which can be easily rotated by an external magnetic field M. The combination of natural and synthetic antiferromagnets can be compared to the setup according to Figure 1b. Fig. 1b lead to larger fields and better temperature stability.

[0042] The following section explains so-called TMR structures as further examples of xMR structures. The range of applications for TMR structures is similar to that of GMR structures. Fig. Figure 2 shows a typical TMR structure 120. The tunnel magnetoresistance (TMR) is obtained in tunnel contacts where two ferromagnetic electrodes 122, 126 are decoupled by a thin insulating tunnel barrier 124. Electrons can tunnel through this thin barrier 124 between the two electrodes 122, 126. The tunnel magnetoresistance is based on the fact that the tunneling current depends on the relative orientation of the magnetization direction in the ferromagnetic electrodes. Compared with GMR structures, TMR structures are often operated in a so-called CIPP configuration (CPP = current-perpendicular-to-plane), i.e., the applied current flows perpendicularly to the layer structure or the top surface of the chip.

[0043] The exemplary embodiments of xMR structures described above thus include an electrical characteristic that depends on an applied magnetic field; that is, the resistivity of an xMR structure of a magnetoresistive device is influenced by an external magnetic field. xMR structures can be implemented in the form of a semiconductor chip and can measure an external magnetic field in the chip plane, i.e., in a plane parallel to an upper surface of the chip. xMR sensors exhibit primary sensitivity in the chip plane for detecting a magnetic field applied within this chip plane. However, measurement results from xMR sensors can be inaccurate for various reasons. Inaccuracies can occur, for example, due to magnetic field components perpendicular to the chip plane. Another phenomenon of xMR sensors is that xMR sensor bridges also provide a signal when no magnetic field is applied.This phenomenon depends on the manufacturing and geometry of the xMR sensor and is also random, so it cannot be definitively guaranteed whether the output-in-plane (e.g. X, Y) values ​​are actually valid and whether the magnetic field is no longer applied to the xMR sensor due to a disturbance in the overall arrangement.

[0044] Several embodiments address these and other problems by combining at least one xMR sensor element with at least one Hall sensor element. Both sensor types can be integrated on separate semiconductor substrates or a common semiconductor substrate using typical semiconductor processes. The Hall sensor element can be used to verify and correct a measurement signal from the xMR sensor element. The xMR sensor element and the Hall sensor element are preferably sensitive to the same magnetic field components, e.g., in-plane magnetic field components (parallel to an upper surface of the sensor elements) or out-of-plane magnetic field components (perpendicular to the upper surface of the sensor elements). It is assumed that the upper surfaces of the xMR and Hall sensor elements are parallel (within typical manufacturing tolerances).However, the person skilled in the art, who benefits from the present disclosure, recognizes that the principles described here are applicable not only to combinations of xMR sensors with Hall sensors, but also to combinations of any magnetic field sensors with Hall sensors. In other words, the Hall sensor element can be used to generally verify and correct a measurement signal from a magnetic field sensor element. In some embodiments, the magnetic field sensor element can therefore also be a Hall sensor element.

[0045] Fig. Figure 3 shows a cross-section of a magnetic field sensor component 300 according to an example of the present disclosure.

[0046] The magnetic field sensor element 300, which can be an integrated semiconductor-based sensor element, comprises one or more magnetic field sensor elements 302 configured to generate a first sensor signal 304 responding to an external magnetic field 306. The magnetic field sensor element 300 also comprises one or more Hall sensor elements 308 configured to generate at least one second sensor signal 310 responding to the external magnetic field 306. The example shows a first and a second Hall sensor element 308-1 and 308-2, as well as the respective sensor signals 310-1 and 310-2. A compensation logic or processor 312, which is associated with the magnetic field sensor element 300, is configured to compensate one of the first sensor signal 304 and the at least one second sensor signal 310 using the respective other sensor signal.At its output, the compensation logic 312 provides a compensated or corrected output signal 314. Thus, the compensation logic 312 can be configured to correct the first sensor signal 304, which indicates the magnetic field 306, based on at least one second sensor signal 310, which indicates the same magnetic field 306.

[0047] In some embodiments, at least one magnetic field sensor element 302, at least one Hall sensor element 308, and analog and / or digital circuit elements of the compensation logic 312 can be integrated on a common semiconductor substrate, resulting in a semiconductor chip with the various components. However, the person skilled in the art, who benefits from the present disclosure, recognizes that the individual components can also be implemented on separate chips. They can, for example, also be integrated into a common semiconductor package.

[0048] In general, the magnetic field sensor element 302 can be based on various technologies for detecting magnetic fields. Thus, the magnetic field sensor element 302 can comprise one or more xMR sensor elements in some examples, e.g., AMR, GMR, or TMR sensor elements. In other embodiments of implementations, the magnetic field sensor element 302 can alternately or additionally comprise one or more Hall sensor elements, e.g., vertical Hall sensor elements.

[0049] In the example shown of Fig. 3. The at least one magnetic field sensor element 302 comprises one or more xMR sensor elements formed in a vertical stack of ferromagnetic and non-magnetic layers. The layer stack can be formed on a substrate, e.g., a semiconductor substrate. The embodiment of the xMR sensor element 302 is operated in a CIP configuration to generate the first sensor signal 304. Thus, the xMR sensor element 302 can, for example, be a GMR sensor element. However, the person skilled in the art, who benefits from the present disclosure, recognizes that in other implementations a CPP (current perpendicular-to-plane) configuration, e.g., with respect to TMR sensor elements, is also possible.

[0050] In the illustrated example, the magnetic field sensor element 302 is configured to generate the first sensor signal 304 responding to the external magnetic field 306, which is parallel to an upper surface 318 of the magnetic field sensor element 302 or of a semiconductor chip encompassing the magnetic field sensor element 302. Thus, the magnetic field sensor element 302 is sensitive to and / or configured to measure magnetic field components (e.g., X, Y) parallel to the layers of the stack that form the magnetic field sensor element 302. In other words, the magnetic field sensor element 302 can be used to measure in-plane magnetic field components.

[0051] By incorporating the magnetic field sensor element 302 into a differential measurement setup, e.g. a Wheatstone bridge, the magnetic field sensor element 302 can be used as a magnetic angle or position sensor, or as part of one in some implementations.

[0052] In some examples, at least one Hall sensor element 308 can be implemented as a vertical Hall sensor element. A vertical Hall sensor is a magnetic field sensor sensitive to a magnetic field extending parallel to the top surface of a semiconductor chip. Like all Hall sensors, a vertical Hall sensor is based on the Hall effect. The Hall effect utilizes the Lorentz force, which deflects moving charges in the presence of a magnetic field perpendicular to the current flow through the sensor or Hall plate. A Hall plate can be a thin piece of semiconductor or metal with length l, width w, and thickness t. The deflection causes charge separation, which generates an electric Hall field. This electric field acts on the charge in the opposite direction to the Lorentz force.Both forces balance each other and create a potential difference perpendicular to the direction of current flow. The potential difference can be measured as a Hall voltage and varies linearly with the magnetic field for small values. For example, a vertical Hall sensor can be implemented by an electrically conductive trough of a first conductivity type (p-type or n-type) embedded in an electrically conductive region of a second conductivity type (n-type or p-type), and a number of contacts that make contact with the trough. The contacts can be used to generate an electric current and to tap the Hall voltage due to the external magnetic field 306 parallel to the upper surface 318. Fig. Figure 4 schematically illustrates how a Hall voltage can be generated between two contacts 402 and 404 due to a lateral current flow in a vertical Hall sensor setup and a magnetic field B parallel to the chip surface. For simplicity, it shows Fig. 3 only the contacts of the vertical Hall sensor elements 308-1, 308-2 for tapping the respective Hall voltages as sensor signals 310-1, 310-2. Thus, at least one Hall sensor element 308 can be a vertical Hall sensor element and can be configured to generate the second sensor signal 310 responding to the magnetic field 306 parallel to the upper surface of the magnetic field sensor element 302 and / or parallel to an upper surface of the vertical Hall sensor element 308.

[0053] As will become clear below, the Hall sensor element or Hall plate 308 is advantageously installed with a fixed, predefined orientation relative to a reference direction of the magnetic field sensor element 302 and is configured for current flow along the predefined orientation or direction. For example, the length l of the Hall sensor element or Hall plate 308 can be assumed to extend along the predefined orientation or direction. The length l can typically be greater than the width w and the thickness t. In other words, the current flow (in the absence of an external magnetic field) in the vertical Hall sensor element or Hall plate 308 is along the predefined orientation or direction. Thus, the predefined orientation can also be defined as a straight line extending through the supply electrodes of the Hall sensor element 308.

[0054] The compensation logic 312 can be configured to apply a correction to the first sensor signal 304, at least if the second sensor signal 310 indicates an orientation of the magnetic field 306 parallel or perpendicular to an orientation of the Hall sensor element 308, and if the first sensor signal 304 indicates a different orientation of the magnetic field 306. This will be explained in more detail below.

[0055] Fig. Figure 5a shows a schematic top view of a magnetic angle sensor component 500 according to an example.

[0056] The magnetic angle sensor element 500 comprises an xMR angle sensor element 502 configured to generate an angle sensor signal in response to an external magnetic field 506 impinged (hit) on the magnetic angle sensor element 500 or the xMR angle sensor element 502. In the illustrated example, the magnetic angle sensor element 500 further comprises six vertical Hall sensor elements 508-1 to 508-6, installed in different orientations relative to the xMR angle sensor element 502 or a reference orientation 501. In the example of Fig. 5a The vertical Hall sensor elements 508 are implemented above or below the xMR angle sensor element 502 within the same chip. In other words, the chip areas occupied by the xMR angle sensor element 502 and the vertical Hall sensor elements 508 can overlap.

[0057] Another example is in Fig. 6a-c shown. The example of Fig. 6a-c differs from Fig. 5a-c such that the vertical Hall sensor elements 508 of Fig. 6a-c are implemented outside the area covered by the xMR angle sensor element 502. In other words, the chip areas occupied by the xMR angle sensor element 502 and the vertical Hall sensor elements 508 overlap in the example of Fig. 6 not.

[0058] In any case, the relative positioning between xMR angle sensor element(s) and vertical / vertical Hall sensor element(s) should be chosen such that both sensor types essentially measure the same (identical) external magnetic field.

[0059] In the examples shown, a first Hall plate or Hall sensor element 508-1 is installed at a 0° angle with respect to the reference orientation 501 and is configured to generate a first Hall sensor signal responding to the (external) magnetic field 506. A second Hall plate or Hall sensor element 508-2 is installed at a 30° angle with respect to the reference orientation 501 and is configured to generate a second Hall sensor signal responding to the magnetic field 506. A third Hall plate or Hall sensor element 508-3 is installed at a 60° angle with respect to the reference orientation 501 and is configured to generate a third Hall sensor signal responding to the magnetic field 506.A fourth Hall plate or Hall sensor element 508-4 is installed at a 90° angle with respect to the reference orientation 501 and is configured to generate a fourth Hall sensor signal responding to the magnetic field 506. A fifth Hall plate or Hall sensor element 508-5 is installed at a 120° angle with respect to the reference orientation 501 and is configured to generate a fifth Hall sensor signal responding to the magnetic field 506. A sixth Hall plate or Hall sensor element 508-6 is installed at a 150° angle with respect to the reference orientation 501 and is configured to generate a sixth Hall sensor signal responding to the magnetic field 506. The person skilled in the art, who benefits from the present disclosure, will of course recognize that the number and angular offsets of the Hall sensor elements 508 are only exemplary and differ from the examples shown. Fig. 5 and Fig. 6 can be distinguished.

[0060] A compensation logic (not shown) can be configured to correct the (inaccurate) angle sensor signal of the xMR angle sensor element 502 based on one or more of the Hall sensor signals of the vertical Hall sensor elements 508. The compensation logic can be implemented by hardware and / or software. In one example, the compensation logic is implemented by a circuit arrangement integrated on the same chip as the xMR angle sensor element 502 and the vertical Hall sensor elements 508.

[0061] Fig. Figure 5b represents a situation where the direction of the external magnetic field 506 is perpendicular to the orientation of the vertical Hall plate, which is arranged at a 30° angle with respect to the reference direction 501. When the external magnetic field direction is perpendicular to a vertical Hall plate, the voltage of the respective Hall sensor element 508 experiences its maximum or minimum Hall voltage (V). Hall(= Max / Min). This can indicate the defined direction of the external magnetic field 506 to the chip or logic. For example, if the external magnetic field has a direction of 30°, the associated vertical Hall plate 508-2, oriented perpendicular to 30°, can indicate a maximum signal to the chip or processor. Detection of the maximum or minimum of the Hall voltage can be achieved by differentiating the sensor signal (Hall voltage). If the derivative of the sensor signal crosses zero from positive to negative, a maximum can be detected. If the derivative of the sensor signal crosses zero from negative to positive, a minimum can be detected.

[0062] If, in the example case of Fig. 5b If the angle sensor signal of the xMR angle sensor element 502 indicates an angle of 30.3°, the chip or compensation logic 312 can detect the 0.3° angular error due to the maximum Hall voltage at the vertical Hall plate 508-2 and compensate the output value 314 by -0.3°, resulting in 30°. Using the same principle, angular errors can be determined using the remaining Hall sensor elements 508, which are assigned to 0°, 60°, 90°, 120°, and 150°. In other words, the angular error of the sensing element can be detected in each direction of the vertical Hall element orientations. By evaluating the maximum and minimum values, it is only necessary to cover 180° with Hall plates.

[0063] Upon examining the vertical Hall plate 508-5, it can be seen that the direction of the external magnetic field 506 is parallel to the orientation of the vertical Hall plate, which is arranged at a 120° angle with respect to the reference direction 501 (or at a 30° angle with respect to the 0° direction). The same applies to the Fig. Example 6b is shown. If the external magnetic field direction is parallel to a vertical Hall plate 508, the voltage of the Hall sensor element V is Hall = 0 V. This can also indicate the direction of the external magnetic field to the chip / logic. For example, if the external magnetic field 506 has a direction of 120° with respect to the reference direction 501, the vertical Hall plate 508-5, which is oriented at 120°, can also provide the chip / logic with a corresponding signal (V). Hall= 0V). When pairing two vertical Hall effect sensors, it is only necessary to cover 180° with Hall effect plates. By pairing the vertical Hall effect plates, the second half of the 360° can be detected by the sign of the second vertical Hall effect plate. For example, 30° can be detected if V Hall = Max, 210° can be detected if V Hall = Min (see Fig. 5c, Fig. 6c).

[0064] A compensation curve (see Figure 508) can be obtained by (e.g., linear) interpolation between the calibration points (0°, 30°, 60°, 90°, 120°, 150°) which are defined by the orientations of the Hall sensor elements 508. Fig. 7a, b) can be calculated and can be used to compensate for the angular error over the entire angular range. For example, if the angular error at 0° was determined to be 0.1° and the angular error at 30° is 0.3°, the interpolated angular error at 15° would be 0.2°. If the angular error at 60° was determined to be 0.4°, the interpolated angular error at 45° would be 0.35°.

[0065] The person skilled in the art, who sees an advantage in the present disclosure, recognizes that calibration points (Hall sensor elements) 308, 508 allow the compensation of even varying measurement errors of the magnetic field sensor element 302, 502, e.g., due to different temperatures or aging. If, for example, the angular error at a specific angle (e.g., 0°) is determined to be 0.2° at a first time instant and the angular error at the same angle is determined to be 0.4° at a second time instant, the compensation at both time instants leads to the correct measurement. Thus, variations in measurement errors can be tracked using the principles presented here.

[0066] The person skilled in the art who benefits from the present disclosure further recognizes that the information relating to Fig. 5 (V Hall ( = Max / Min) and Fig. 6 (V HallThe different effects described (= 0) can be used separately or in combination to correct the angle sensor signal of the xMR angle sensor element 502.

[0067] In summary, Fig. Figure 8 presents a basic flowchart of a magnetic field detection method 800 according to an example.

[0068] Method 800 comprises measuring 810 a magnetic field using a magnetic field sensor element, which may be an xMR sensor element. Method 800 further comprises measuring 820 the magnetic field using at least one (vertical) Hall sensor element with a predetermined orientation relative to the magnetic field sensor element and correcting 830 the measurement of the magnetic field sensor element based on the measurement of the at least one Hall sensor element. As previously described, the measurement of the magnetic field sensor element can be corrected, at least when the measurement of the Hall sensor element indicates an orientation of the magnetic field parallel or perpendicular to the predetermined orientation of the Hall sensor element, and when the measurement of the magnetic field sensor element indicates a different orientation of the magnetic field. A plurality of Hall sensor elements with respective different orientations can be used.

[0069] In embodiments of the present disclosure, the accuracy of the chip layout can be transferred to the angular accuracy. Furthermore, the compensation of the angular error in an angle sensor chip can be performed in real time. Some embodiments use vertical Hall elements that generate a number of "calibration points" directly on the semiconductor substrate, e.g., silicon. Each vertical Hall element can be oriented in a specific direction. When the external magnetic field is applied in a direction orthogonal to a calibration point, it indicates a maximum or minimum signal to the chip. When the external magnetic field is applied in a direction parallel to a calibration point, it can indicate a zero signal to the chip. Thus, the chip / logic can detect when the direction of the external magnetic field is perpendicular or parallel to the calibration point and compare it with the angular value of the sensing element.This deviation can be compensated for in the output angle value. The result is the angular error in the directions of each calibration point. The angular error between calibration points can be interpolated, thus allowing compensation across the entire angular range of the sensor.

[0070] In some embodiments, real-time compensation of the angular error can be achieved within the angle sensor chip itself through a combination of xMR and Hall sensor elements. This compensation is dynamically effective across different temperature and lifetime drifts.

[0071] Exemplary embodiments of the present disclosure allow for greater angular accuracy and reduced effort in a modular application. Users who normally employ lookup tables (LUTs) to compensate for portions of the angular error no longer need to measure the angle sensor characteristics and store them in memory. Furthermore, they can achieve better compensation results because the calibration is dynamic and also accounts for changes in characteristics due to temperature and lifetime. When programming an LUT for compensation, they can always compensate for a defined characteristic, even if it changes.

[0072] Angular error compensation can be used to improve the accuracy of xMR angle sensors by combining xMR and Hall sensors on chips with a specific layout and orientation of the Hall plates. In some implementations, an important aspect is the array and orientation of the additional Hall plates, which establish the calibration points and act as reference encoders.

[0073] There are many angle sensors on the market. Compensation using specially oriented Hall elements can be implemented in several angle sensors, not just xMR-based ones. Since the compensation is independent of the specific angle sensing element (and thus the physical effect of the sensor element) and only acts additionally, it can also be used, for example, in a Hall-effect angle sensor. This would be a Hall-Hall combination. Therefore, the principles of this disclosure can be implemented in any angle sensor.

[0074] The principles of the present disclosure can also be used for specially oriented xMR sensors as calibration or reference sensors.

[0075] Thus, another magnetic angle sensor component according to the present disclosure can comprise a magnetic angle sensor element configured to generate an angle sensor signal responding to an external magnetic field acting upon the magnetic angle sensor element. As previously explained, the magnetic angle sensor element can, in principle, be implemented according to any suitable magnetic sensor technology, e.g., based on the Hall effect or magnetoresistive effects, e.g., GMR, TMR.

[0076] The magnetic angle sensor device can further comprise a first xMR sensor element having a first fixed and defined magnetic direction / orientation of its hard magnetic layer(s) with respect to the magnetic angle sensor element or a reference direction / orientation, and configured to generate a first xMR sensor signal responding to the external magnetic field. The magnetic angle sensor device can further comprise at least one second xMR sensor having a second fixed and defined magnetic orientation of its hard magnetic layer(s) with respect to the magnetic angle sensor element or the reference direction / orientation, and configured to generate a second xMR sensor signal responding to the external magnetic field. The hard magnetic layer(s) can be hard magnetic, for example, by an exchange that pins (fixes) it to an antiferromagnet.The xMR sensor elements can be, for example, GMR or TMR sensor elements.

[0077] As previously explained, a compensation logic or processor can be implemented to correct the angle sensor signal based on the first and / or the second xMR sensor signal. The first and second xMR sensor signals can be considered reference or calibration signals.

[0078] When the direction of the external magnetic field is parallel to the orientation of the hard magnetic layer(s) of an xMR sensor element, the respective xMR sensor element experiences minimal electrical resistance in some cases. Conversely, when the direction of the external magnetic field is antiparallel to the orientation of the hard magnetic layer(s) of the xMR sensor element, the respective xMR sensor element experiences maximum electrical resistance. Similar to the situation described above, the respective xMR sensor element thus experiences its maximum or minimum sensor signal. This can indicate the defined direction of the external magnetic field to the chip or logic. For example, if the external magnetic field has a direction of 30°, a corresponding xMR sensor element with a hard magnetic layer orientation of 30° can indicate a maximum signal to the chip or processor.Detecting the maximum or minimum of the xMR sensor signal can be achieved, for example, by differentiating the sensor signal. A maximum can be detected when the derivative of the sensor signal crosses zero from positive to negative. Conversely, a minimum can be detected when the derivative of the sensor signal crosses zero from negative to positive.

[0079] The description and drawings represent only the principles of the invention. Those skilled in the art will therefore be able to devise various arrangements which, although not explicitly described or shown here, embody the principles of the invention and are encompassed within its essence and scope. Furthermore, all examples given here are expressly for teaching purposes only, to assist the reader in understanding the principles of the invention and the concepts contributed by the inventor(s) to the advancement of the technology, and should be understood as serving without limitation to such specifically listed examples and conditions. Furthermore, all statements made herein concerning principles, aspects, and embodiments of the invention, as well as specific examples thereof, are intended to encompass their equivalents.

[0080] Furthermore, the following claims are hereby included in the detailed description, where each claim may stand alone as a separate embodiment. While each claim may stand alone as a separate embodiment, it should be noted that—although a dependent claim may refer to a particular combination with one or more other claims—other embodiments may also include a combination of the dependent claim with the subject matter of any other dependent claim. These combinations are suggested here unless it is stated that a particular combination is not intended. Furthermore, features of a claim are also included for each other independent claim, even if that claim is not directly dependent on the independent claim.

[0081] It should also be noted that methods disclosed in the description or in the claims may be implemented by a device with means for carrying out each of the respective steps of these methods.

[0082] Furthermore, it is understood that the disclosure of multiple steps or functions in the description or claims should not be interpreted as being in a specific order. The disclosure of multiple steps or functions therefore does not restrict them to a specific order, unless these steps or functions are not interchangeable for technical reasons. Furthermore, in some embodiments, a single step may include or be subdivided into several substeps. Such substeps may be included and form part of the disclosure of that single step, unless they are expressly excluded.

Claims

[1] A magnetic field sensor (300; 500), comprising: at least one magnetic field sensor element (302; 502) configured to generate a first sensor signal (304) responding to a magnetic field (306; 506); at least one Hall sensor element (308; 508) configured to generate a second sensor signal (310) responding to the magnetic field (306; 506), wherein the Hall sensor element (308; 508) is a vertical Hall sensor element and is configured to generate the second sensor signal (310) responding to a magnetic field (306; 506) parallel to an upper surface of the magnetic field sensor element and / or parallel to an upper surface of the vertical Hall sensor element; a compensation logic (312) configured to compensate one of the first and the second sensor signals using the other sensor signal. [2] The magnetic field sensor (300; 500) according to claim 1, wherein the magnetic field sensor element (302; 502) is configured to generate the first sensor signal (304) responding to a magnetic field (306; 506) parallel to the upper surface of the magnetic field sensor element. [3] The magnetic field sensor (300; 500) according to one of the preceding claims, wherein the magnetic field sensor element (302; 502) comprises a magnetoresistive sensor element. [4] The magnetic field sensor (300; 500) according to claim 3, wherein the magnetoresistive sensor element (302; 502) is a giant magnetoresistive, GMR, sensor element, a tunnel magnetoresistive, TMR, sensor element, or an anisotropic magnetoresistive, AMR, sensor element. [5] The magnetic field sensor (300; 500) according to one of the preceding claims, wherein the Hall sensor element (308; 508) is installed with a fixed predefined orientation relative to a reference direction (501) of the magnetic field sensor element and is configured for a current flow along the predefined orientation. [6] The magnetic field sensor (300; 500) according to one of the preceding claims, wherein the compensation logic (312) is configured to correct the first sensor signal (304) indicating the magnetic field, based on the second sensor signal (310) indicating the magnetic field. [7] The magnetic field sensor (300; 500) according to one of the preceding claims, wherein the compensation logic (312) is configured to apply a correction to the first sensor signal (304), at least when the second sensor signal (310) indicates an orientation of the magnetic field (306; 506) parallel or perpendicular to an orientation of the Hall sensor element (308; 508) and when the first sensor signal (304) indicates a different orientation of the magnetic field (306; 506). [8] The magnetic field sensor (300; 500) according to one of the preceding claims, comprising: a first Hall sensor element (308-1; 508-1) installed in a first orientation with respect to the magnetic field sensor element (302; 502) and configured to generate a first Hall sensor signal (310-1) responding to the magnetic field (306; 506); and at least a second Hall sensor element (308-2; 508-2) installed in a second orientation with respect to the magnetic field sensor element and configured to generate a second Hall sensor signal (310-2) responding to the magnetic field (306; 506); wherein the compensation logic (312) is configured to compensate the first sensor signal (304) based on the first and / or the second Hall sensor signal (310-1; 310-2). [9] The magnetic field sensor (300; 500) according to one of the preceding claims, wherein the at least one magnetic field sensor element (302; 502) and the at least one Hall sensor element (308; 508) are integrated in the same semiconductor package or on the same semiconductor chip. [10] A magnetic angle sensor (300; 500), comprising: a magnetoresistive angle sensor element (302; 502) configured to generate an angle sensor signal (304) responding to a magnetic field (306; 506) acting on the magnetoresistive angle sensor element (302; 502); a first vertical Hall sensor element (308-1; 508-1) installed in a first orientation with respect to the magnetoresistive angle sensor element (302; 502) and configured to generate a first Hall sensor signal (310-1) responding to the magnetic field; at least a second vertical Hall sensor element (308-2; 508-2) installed in a second orientation with respect to the magnetoresistive angle sensor element (302; 502) and configured to generate a second Hall sensor signal (310-2) responding to the magnetic field; a processor (312) configured to correct the angle sensor signal (304) based on the first and / or the second Hall sensor signal (310-1; 310-2). [11] The magnetic angle sensor (300; 500) according to claim 10, wherein the processor (312) is configured to correct the angle sensor signal, at least when the first Hall sensor signal indicates an orientation of the magnetic field parallel or perpendicular to the first orientation and when the angle sensor signal indicates a different orientation of the magnetic field, or when the second Hall sensor signal indicates an orientation of the magnetic field parallel or perpendicular to the second orientation and when the angle sensor signal indicates a different orientation of the magnetic field. [12] The magnetic angle sensor (300; 500) according to claim 10 or 11, wherein the magnetoresistive angle sensor element (302; 502), the first and the second vertical Hall sensor element (308-1; 508-1; 308-2; 508-2) are integrated in the same semiconductor package or on the same semiconductor chip. [13] A magnetic angle sensor comprising: a magnetic angle sensor element (302; 502) configured to generate an angle sensor signal (304) responding to a magnetic field (306; 506) acting on the magnetic angle sensor element (302; 502); a first magnetoresistive sensor element having a first predefined magnetic orientation of its hard magnetic layer with respect to the magnetic angle sensor element (302; 502) and configured to generate a first reference sensor signal responding to the magnetic field (306; 506); at least a second magnetoresistive sensor element having a second predefined magnetic orientation of its hard magnetic layer with respect to the magnetic angle sensor element (302; 502) and configured to generate a second reference sensor signal responding to the magnetic field (306; 506); a processor (312) configured to correct the angle sensor signal (304) based on the first and / or the second reference sensor signal. [14] The magnetic angle sensor according to claim 13, wherein the processor (312) is configured to correct the angle sensor signal, at least when the first reference sensor signal indicates an orientation of the magnetic field parallel or perpendicular to the first magnetic orientation and when the angle sensor signal indicates a different orientation of the magnetic field, or when the second reference sensor signal indicates an orientation of the magnetic field parallel or perpendicular to the second magnetic orientation and when the angle sensor signal indicates a different orientation of the magnetic field. [15] A magnetic field detection method (800), comprising: Measuring (810) a magnetic field (306; 506) using a magnetic field sensor element (302; 502); Measuring (820) the magnetic field using at least one Hall sensor element (308; 508) with a predetermined orientation with respect to the magnetic field sensor element; and Correcting (830) the measurement of the magnetic field sensor element based on the measurement of at least one Hall sensor element, wherein the measurement (820) of the magnetic field is carried out using a vertical Hall sensor element (308; 508) which is configured to generate a sensor signal responding to a magnetic field (306; 506) parallel to an upper surface of the magnetic field sensor element and / or parallel to an upper surface of the vertical Hall sensor element. [16] The magnetic field detection method (800) according to claim 15, wherein the measurement of the magnetic field sensor element (302; 502) is corrected, at least when the measurement of the vertical Hall sensor element (308; 508) indicates an orientation of the magnetic field parallel or perpendicular to the predetermined orientation of the Hall sensor element and when the measurement of the magnetic field sensor element indicates a different orientation of the magnetic field. [17] The magnetic field detection method (800) according to claim 15 or 16, comprising measuring (820) the magnetic field using at least one Hall sensor element (308; 508): Measuring the magnetic field using a first vertical Hall sensor element (308-1; 508-1) with a first orientation with respect to the magnetic field sensor element; Measuring the magnetic field using at least one second vertical Hall sensor element (308-2; 508-2) with a second orientation with respect to the magnetic field sensor element. [18] The magnetic field detection method (800) according to claim 17, wherein the measurement of the magnetic field sensor element (302; 502) is corrected, at least when the measurement of the first vertical Hall sensor element indicates an orientation of the magnetic field parallel or perpendicular to the first orientation and when the measurement of the magnetic field sensor element indicates a different orientation of the magnetic field, or at least when the measurement of the second vertical Hall sensor element indicates an orientation of the magnetic field parallel or perpendicular to the second orientation and when the measurement of the magnetic field sensor element indicates a different orientation of the magnetic field.

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