Angular position sensor with high accuracy, device, magnetic source and system

Abstract

A sensor device (100) for determining an absolute angular position (θ) of a magnetic source (110) having an inner magnet portion (111) being a magnetic dipole, and an outer magnet portion (112) being a multipole ring magnet, the sensor device being a single packaged device comprising: a first sensor group for measuring a first set of at least two magnetic field components or magnetic field gradients at a first sensor location (gc1); a second sensor group for measuring a second set of at least two magnetic field components or magnetic field gradients at a second sensor location (gc2) spaced from the first sensor location (gc1) by a predefined distance (ds); output means for outputting the first and second set of signals, or one or more signals derived therefrom. Said magnetic source (110). An angular position sensor system (120; 1420) comprising said sensor device and said magnetic source.

Description

[0001] ANGULAR POSITION SENSOR WITH HIGH ACCURACY, DEVICE, MAGNETIC SOURCE AND SYSTEM

[0002] Field of the invention

[0003] The present invention relates in general to the field of magnetic position sensors, and more in particular to an angular position sensor device, a magnetic source, and an angular position sensor system.

[0004] Background of the invention

[0005] Magnetic position sensor systems, in particular linear or angular position sensor systems are known in the art. They offer the advantage of being able to measure a linear or an angular position without making physical contact, thus avoiding problems of mechanical wear, scratches, friction, etc.

[0006] Many variants of magnetic position sensor systems exist, addressing one or more of the following requirements: using a simple or cheap magnetic structure, using a simple or cheap sensor device, being able to measure over a relatively large range, being able to measure with great accuracy, requiring only simple arithmetic, being able to measure at high speed, being highly robust against positioning errors, being highly robust against an external disturbance field, providing redundancy, being able to detect an error, being able to detect and correct an error, having a good signal-to-noise ratio (SNR), etc.

[0007] Often two or more of these requirements conflict with each other, hence a trade-off needs to be made.

[0008] There is always room for improvements or alternatives.

[0009] Summary of the invention

[0010] It is an object of embodiments of the present invention to provide a magnetic source, and a position sensor device, and a position sensor system capable of measuring an absolute angle over a full 360° range, with high accuracy and high sensitivity.

[0011] It is an object of embodiments of the present invention that it can be miniaturized (e.g. having an outer diameter of 15 mm or less, e.g. 12 mm or less, e.g. about 10 mm).

[0012] It is an object of embodiments of the present invention to provide such a magnetic source and sensor device, and position sensor system which is highly robust and accurate even under mechanical vibrations.

[0013] It is an object of embodiments of the present invention to provide such a sensor device, and position sensor system which is highly insensitive to an external disturbance field.

[0014] It is an object of embodiments of the present invention to provide a position sensor system which is suitable for use in an industrial, robotic or automotive environment.

[0015] It is an object of embodiments of the present invention to provide a position sensor system comprising a magnetic source with a reduced size, e.g. having an outer diameter of at most 15 mm. It is an object of embodiments of the present invention to provide a position sensor system, wherein the cost of the position sensor device is reduced (e.g. smaller chip area).

[0016] It is an object of embodiments of the present invention to provide a position sensor system that provides high accuracy, without comprising a magnetic shielding.

[0017] It is an object of embodiments of the present invention to provide a position sensor system, wherein the mounting requirements of the sensor device are relaxed.

[0018] It is an object of embodiments of the present invention to provide a position sensor system, that is more robust against ageing effects, (e.g. related to misalignment, mechanical wear, temperature variations, demagnetization, etc.).

[0019] These and other objectives are accomplished by embodiments of the present invention.

[0020] According to a first aspect, the present invention provides a sensor device for determining an absolute angular position (e.g. 9) of said device relative to a magnetic source having an inner magnet portion in the form of a magnetic dipole, and an outer magnet portion in the form of a multipole ring magnet, wherein the sensor device comprises at least one semiconductor substrate defining a first and a second direction (e.g. X, Y) parallel to the semiconductor substrate, and a third direction (e.g. Z) perpendicular to the semiconductor substrate; the sensor device being a single packaged semiconductor device comprising: a first sensor group for measuring a first set of at least two magnetic field components or or at least two magnetic field differences or gradients of a magnetic field as may be generated by the inner magnet portion, at a first sensor location (e.g. gel); a second sensor group for measuring a second set of at least two magnetic field components or at least two magnetic field differences or gradients of a magnetic field as may be generated by the outer magnet portion, at a second sensor location (e.g. gc2) spaced from the first sensor location by a predefined distance (e.g. ds); output means for outputting the first and second set of signals, or one or more signals (e.g. Rl, R2, a, , 9) derived therefrom, for allowing the determination of the absolute angular position (e.g. 9).

[0021] The sensor device may comprise one or more semiconductor substrates incorporated in said single packaged device.

[0022] The first sensor group and the second sensor group may be located on different semiconductor substrates, or on the a same (e.g. single) semiconductor substrate.

[0023] The magnetic sensor elements of the first sensor group and of the second sensor group may be embedded in said at least one semiconductor substrate.

[0024] The first sensor group may be configured for measuring two in-plane components (e.g. Bx and By) or for measuring two out-of-plane gradients (e.g. dBz / dx and dBz / dy).

[0025] The second sensor group may be configured for measuring an in-plane component and an out- of-plane component, or for measuring an in-plane gradient (e.g. dBy / dy) and an out-of-plane gradient (e.g. dBz / dy). It is a major advantage of this sensor device and sensor arrangement that it is capable of measuring an absolute angle over a full 360° range, with high accuracy and high sensitivity.

[0026] It is a major advantage of this sensor device and sensor arrangement that it only requires a single chip package, which reduces cost and simplifies the mounting of the sensor device relative to the magnetic source.

[0027] It is a major advantage of this sensor device and sensor arrangement that it can be highly miniaturized (e.g. the outer diameter of the ring magnet may have a diameter of 15 mm or less, e.g. 12 mm or less, e.g. about 10 mm), which is possible (inter alia) because it was surprisingly found that no magnetic shielding is required.

[0028] It is a further advantage of embodiments that the absolute angle thus determined is highly insensitive to mounting offset in at least some directions, and thus is also highly insensitive to mechanical vibrations.

[0029] It is a further advantage of embodiments that the absolute angle thus determined is highly insensitive to an external disturbance field.

[0030] This sensor device and such a sensor arrangement are ideally suited for position sensing of a miniature electrical motor, e.g. a motor having an external diameter up to 15 mm or less, or up to 12 mm or less, or up to 10 mm.

[0031] Preferably the overall angular position 9 is a value in the range from 0° to 360°.

[0032] The single packaged device may be packaged by a single plastic moulding compound or a single ceramic moulding compound.

[0033] In an embodiment, the packaged device comprises only a single semiconductor substrate, comprising both the first sensor group and the second sensor group and biasing and readout circuitry, and an output circuitry, and optionally other electronic circuitry, such as e.g. a processing circuit, a nonvolatile memory, etc.

[0034] In an embodiment, the packaged device comprises a first and a second semiconductor substrate, the first semiconductor substrate comprising at least the first sensor group, the second semiconductor substrate comprising at least the second sensor group. In an embodiment, this first and second semiconductor substrate may be mechanically mounted to a lead frame and may be electrically interconnected by means of bond wires. In another embodiment, this first and second semiconductor substrate may be electrically interconnected by means of one or more RDL layers and may be wafer- level-packaged (WLP).

[0035] It is an advantage of this sensor device that it can provide signals for determining an absolute angular position, e.g. that an angle in an angular range of 360° can be determined with high resolution and with high accuracy, over a relatively large temperature range (e.g. from -40°C to +160°C). The actual calculation of the absolute angle may be performed inside the sensor device, or outside of the sensor device. It is an advantage that the sensor device can be used in combination with an extremely small magnetic source, e.g. having an outer diameter in the range from about 7.0 to about 12.0 mm.

[0036] It is an advantage of certain embodiments of the sensor device that the absolute angular position can be determined in a manner which is highly insensitive to an external disturbance field.

[0037] It is an advantage of certain embodiments of the sensor device that the absolute angular position can be determined in a manner which is highly insensitive to position offset in at least one direction, but preferably in any direction.

[0038] It is an advantage of certain embodiments of the sensor device that it comprises only horizontal hall elements without integrated magnetic concentrators, or comprises only vertical hall elements, or comprises only horizontal hall elements and one or more integrated magnetic concentrators.

[0039] It is an advantage of certain embodiments of the sensor device that it can be used with magnetic sources having a same outer diameter, but a varying number of alternating poles of the ring portion.

[0040] It is an advantage that of certain embodiments of the sensor device that it is highly insensitive to mounting position offset in one or more of the following directions: axial distance with respect to the magnetic source, radial offset (i.e. in the X-direction), lateral offset (i.e. in the Y-direction).

[0041] It is an advantage of embodiments of the present invention that the overall angular position can be calculated at a relatively high speed because a coarse signal can be easily derived from the signals obtained from the first sensor group, and because the coarse signal can be easily converted to a sector count.

[0042] In preferred embodiments of the present invention, the overall angular position is calculated each time by extracting a sector count from the coarse signal and by adding a corresponding predefined sector offset (e.g. equal to 360° / Npp, where Npp is the number of pole pairs) to the fine angle value.

[0043] The inventors were confronted with the problem of finding a miniature angular position sensor system having an outer diameter smaller than 12.0 mm, that has a 360° range, and that has a high resolution (e.g. at least 14 bits at room temperature and / or at least 10 bits over an automotive temperature range, e.g. from -40°C to +160°C. They came to the idea of using a magnetic source comprising a central two-pole magnet and a single-track multi-pole ring magnet around it, without a magnetic shield between them. It was completely impossible to know beforehand whether such a structure could work and / or to get a realistic idea about signal levels and / or signal-to-noise ratio, and / or amount of cross-talk. Simulations were performed, and they surprisingly discovered that it is indeed possible to use such a magnetic structure without a magnetic shield in between, and get an overall accuracy improvement (as compared to using only a single dipole magnet).

[0044] In an embodiment, the first sensor group is configured for measuring: at least two or three orthogonal magnetic field components (e.g. Bx, By; By, Bz), e.g. three orthogonal components measured at a single sensor location, e.g. as illustrated in FIG. 2A to FIG. 2C; or e.g. two orthogonal components measured at a single sensor location, e.g. as illustrated in FIG. 3A to FIG. 3E; or e.g. at least two in-plane components oriented in orthogonal directions, measured at different sensor locations located on a virtual circle or virtual ellipse, e.g. as illustrated in FIG. 11.

[0045] In an embodiment, the first sensor group is configured for measuring: a magnetic field component (e.g. Bx) oriented in the first direction (e.g. X) and a magnetic field component (e.g. By) oriented in the second direction (e.g. Y), e.g. as illustrated in FIG. 3D, FIG. 3E, FIG. 10, FIG. 11.

[0046] In an embodiment, the first sensor group is configured for measuring: a magnetic field component (e.g. By) oriented in the second direction (e.g. Y) and a magnetic field component (e.g. Bz) oriented in the third direction (e.g. Z), e.g. as illustrated in FIG. 3A to FIG. 3C.

[0047] In an embodiment, the first sensor group is configured for measuring: three orthogonal magnetic field components (e.g. Bx, By, Bz), e.g. as illustrated in FIG. 2A to FIG. 2C.

[0048] In an embodiment, the first sensor group is configured for measuring: three magnetic field components (e.g. Bzl, Bz2, Bz3) oriented in the third direction (e.g. Z), e.g. three components Bzl to Bz3 in three sensor locations located on a virtual circle, spaced apart by multiples of 90°, e.g. as illustrated in FIG. 10; or e.g. three components Bzl to Bz3 in three sensor locations located on a virtual circle, spaced apart by multiples of 120°, e.g. as illustrated in FIG. 4C; or e.g. six components Bzl to Bz6 in six sensor locations located on a virtual circle, spaced apart by multiples of 60°.

[0049] In an embodiment, the first sensor group is configured for measuring: at least four magnetic field components (e.g. Bzl, Bz2, Bz3, Bz4) oriented in the third direction (e.g. Z), e.g. four components Bzl to Bz4 in four sensor locations located on a virtual circle or vertical ellipse, spaced apart by multiples of 90° , e.g. as illustrated in FIG. 4A.

[0050] In an embodiment, the first sensor group is configured for measuring: at least two magnetic field differences or two magnetic field gradients, e.g. two out-of-plane gradients dBz / dx and dBz / dx, e.g. as illustrated in FIG. 4A; or e.g. two pairwise differences Bzl2, Bz23, Bz31, e.g. as illustrated in FIG. 4C.

[0051] In an embodiment, the second sensor group is configured for measuring: at least two orthogonal magnetic field components (e.g. By2, Bz2), e.g. as illustrated in FIG. 3A to FIG. 3C or FIG. 5B.

[0052] In an embodiment, the second sensor group is configured for measuring: a magnetic field component (e.g. By) oriented in the second direction (e.g. Y) and a magnetic field component (Bz) oriented in the third direction (Z), e.g. as illustrated in FIG. 3A to FIG. 3C.

[0053] In an embodiment, the second sensor group is configured for measuring: at least three magnetic field components (e.g. Bzl, Bz2, Bz3) oriented in the third direction (Z), e.g. three components Bzl, Bz2, Bz3 in three sensor locations spaced apart in the second direction (Y), for example on a virtual line, e.g. as illustrated in FIG. 9.

[0054] In an embodiment, the second sensor group is configured for measuring: at least three magnetic field components (e.g. Byl, By2, By3) oriented in the second direction (Y), e.g. three components Byl, By2, By3 in three sensor locations spaced apart in the second direction (Y), for example on a virtual line, e.g. as illustrated in FIG. 11. In an embodiment, the second sensor group is configured for measuring: at least three magnetic field components (e.g. Bxl, Bx2, Bx3) oriented in the first direction (X), e.g. three components Bxl, Bx2, Bx3 in three sensor locations spaced apart in the second direction (Y), optionally located on a virtual line, e.g. described as a variant of FIG. 9 to FIG. 11;

[0055] In an embodiment, the second sensor group is configured for measuring: at least two sets of two orthogonal magnetic field components (e.g. By2, Bz2), e.g. as illustrated in FIG. 4B or FIG. 4D to FIG. 4F.

[0056] In an embodiment, the second sensor group is configured for measuring: at least two sets of three orthogonal magnetic field components (e.g. Bx2,By2,Bz2; e.g. Bx3,By3,Bz3), e.g. as illustrated in FIG. 4G and FIG. 4H.

[0057] In an embodiment, the second sensor group is configured for measuring: at least two magnetic field differences (e.g. diffl, diff2) or two magnetic field gradients (e.g. dBy / dy, dBz / dy; e.g. dBx / dy, dBz / dy).

[0058] In an embodiment, at least one of the first sensor group and the second sensor group comprises an integrated magnetic concentrator (IMC) and a plurality of horizontal Hall elements arranged near a periphery of that integrated magnetic concentrator.

[0059] In an embodiment each of the first sensor group and the second sensor group comprises an integrated magnetic concentrator (IMC) and a plurality of horizontal Hall elements arranged near a periphery of a corresponding integrated magnetic concentrator.

[0060] In an embodiment, at least one of the first sensor group and the second sensor group comprises at least two Hall elements without an integrated magnetic concentrator (IMC).

[0061] In an embodiment, each of the first sensor group and the second sensor group comprises at least two Hall elements without an integrated magnetic concentrator (IMC).

[0062] In an embodiment, the absolute angular position (e.g. 9) is determined by: a) determining a coarse signal (e.g. Rl, a) based on the signals obtained from the first sensor group; b) determining a fine signal (e.g. R2, ) based on the signals obtained from the second sensor group; c) determining the absolute angular position (e.g. 9) based on the coarse signal and the fine signal.

[0063] Step a) may comprise: determining a sector-count and a corresponding sector-offset, based on the signals obtained from the first sensor group.

[0064] Step b) may comprise: determining a second angle 0 based on the signals obtained from the second sensor group, e.g. based on a second ratio R2, e.g. using an arctangent function or using a lookup table.

[0065] For example if the number of pole pairs is 6, the angle 9 may be calculated as: the fine angle 0 divided by 6, plus a sector-offset equal to an integer multiple of 60°. The "integer multiple" may be referred to as "sector-count", and can be determined based on the signals obtained from the first sensor group, e.g. based on a ratio Rl of these signals, or based on an angle a derived from these signals. In an embodiment, the coarse signal is determined as a function of a ratio (Rl) of the at least two magnetic field components measured by the first sensor group, or as a function of a ratio (Rl) of the at least two magnetic field gradients measured by the first sensor group; and the fine signal ( ) is determined as a function of a ratio (R2) of the at least two magnetic field components measured by the second sensor group, or as a function of a ratio (R2) of the at least two magnetic field gradients measured by the second sensor group.

[0066] In this embodiment, the coarse signal (e.g. offset value) and the fine signal are both determined as a function of a ratio, and thus the overall absolute angular position is highly robust against temperature variations and demagnetization.

[0067] If the fine signal is determined based on a ratio of magnetic field gradients, the overall absolute angular position is furthermore highly robust against an external disturbance field. It is not absolutely required that the coarse signal is also based on a ratio of magnetic field gradients, but it may.

[0068] In an embodiment, the sensor device comprises a non-volatile memory for storing an (e.g. a random or pseudo-random) angular offset value between the inner magnet portion and the outer magnet portion, which value is determined during a calibration procedure; and wherein the absolute angular position (e.g. 9) is determined taking into account the angular offset value stored in the nonvolatile memory. This sensor device can be used in combination with magnetic sources in which the inner magnet portion and the outer magnet portion are not perfectly aligned.

[0069] In an embodiment, a distance (e.g. ds) between a geometric centre (gel) of the first sensor group and a geometric centre (gc2) of the second sensor group is a value in the range from 1.0 to 4.0 mm, or in the range from 1.5 to 3.5 mm, or in the range from 2.0 to 3.5 mm, or in the range from 2.5 to 3.5 mm.

[0070] According to a second aspect, the present invention also provides a magnetic source comprising: an inner magnet portion in the form of a magnetic dipole; an outer magnet portion in the form of a multipole ring magnet.

[0071] The inner magnet portion and the outer magnet portion may be integrally formed, or may be separately formed and then fixedly connected to each other, for example by means of glue or by means of a plastic or by means of aluminum or an aluminum alloy or combinations hereof.

[0072] A surface of the inner magnet portion and a surface of the outer magnet portion may be radially separated, e.g. by a non-magnetic material, such as e.g. aluminium or aluminium alloy or a plastic, or by a groove, but that is not absolutely required, and in certain embodiments, the inner magnet portion and the outer magnet portion may be in direct physical contact with each other (thus without a magnetic shielding between them).

[0073] In an embodiment, the multipole ring magnet is axially magnetized, or tangentially magnetized, or radially magnetized, or AL (axial lateral or arc shaped) magnetized (e.g. as illustrated in FIG. 1H). In an embodiment, the multipole ring magnet has only a single track. It is an advantage when the outer ring has only a single track, because this allows the diameter of the outer magnet portion to be reduced. Preferably this single track has at least three pole pairs, thus at least six alternating magnetic poles, each pole extending over an angular range of at most 36076=60°. In other embodiments the single track comprises at least four pole pairs (each pole extending over 360° / 8=45°), or at least five pole pairs (each pole extending over 360° / 10=36°), or at least six pole pairs (each pole extending over 360° / 12=30°).

[0074] In an embodiment, the multipole ring magnet is radially magnetized, and has two concentric tracks. In this case, each track preferably has at least three pole pairs, or at least four pole pairs, or at least five pole pairs, or at least six pole pairs.

[0075] Preferably the magnetic poles are equidistantly spaced, or stated in other words: preferably the pole pitch between any two adjacent poles is constant.

[0076] Preferably the multipole ring magnet and the inner magnet are concentrically aligned, meaning they have a common central axis.

[0077] In an embodiment, the inner magnet is a diametrically magnetized dipole, and the outer magnet portion is axially or tangentially or axial-lateral (AL) magnetized. This offers the advantage of reduced cross-talk.

[0078] In an embodiment, the inner magnet is an axially magnetized dipole, and the outer magnet portion is radially magnetized. This also offers a reduced cross-talk.

[0079] In an embodiment, the multipole ring magnet has at least 3 pole pairs (thus at least six poles facing the sensor device), or at least 4 pole pairs, or at least 5 pole pairs, or at least 6 pole pairs, or at least 7 pole pairs, or at least 8 pole pairs.

[0080] In an embodiment, the multipole ring magnet has at most 20 pole pairs (thus at most forty poles facing the sensor device), or at most 18 pole pairs, or at most 16 pole pairs, or at most 14 pole pairs, or at most 12 pole pairs, or at most 10 pole pairs.

[0081] In an embodiment, the multipole ring magnet has 4 to 15 pole pairs, or from 6 to 12 pole pairs.

[0082] In an embodiment, the multipole ring magnet has 2N pole pairs, i.e. 4N poles, N being an integer number of at least 2. This ring magnet has for example 4 or 8 or 12 or 16 or 20 magnetic poles.

[0083] In an embodiment, the multipole ring magnet has 2N+1 pole pairs, i.e. 4N+2 poles, N being an integer number of at least 2. This ring magnet has for example 6 or 10 or 14 or 18 magnetic poles.

[0084] In an embodiment, the multipole ring magnet has 4N pole pairs, i.e. 8N poles, N being an integer number of at least 1. This ring magnet has for example 8 or 16 or 24 magnetic poles.

[0085] In an embodiment, the multipole ring magnet has 4N+2 pole pairs, i.e. 8N+4 poles, N being an integer number of at least 1. This ring magnet has for example 12 or 20 or 28 magnetic poles. In preferred embodiments, the inner magnet has a cylindrical shape, e.g. a cylindrical shape that is completely filled, without any openings, but the upper and / or lower circular rim may be bevelled, e.g. for easy mounting inside the ring magnet or for easy mounting in an aluminum tube, or the like.

[0086] In an embodiment, the inner magnet is spaced apart from the outer magnet portion, e.g. by means of a non-ferromagnetic material such as e.g. aluminum or air or a plastic material. The space between the inner and outer magnet portion can be referred to as "code-free region".

[0087] In another embodiment, the inner magnet substantially abuts the outer magnet portion. In this case, the outer diameter DI of the dipole magnet is substantially equal to the inner diameter of the ring magnet. In this case, the magnet assembly does not have a "code-free region". Preferably, in this case, the inner magnet may have a frusto-conical shape, and the ring magnet may have a frusto-conical opening. In this way, tolerances on the magnet dimensions may be reduced, and their assembly may be easier.

[0088] In an embodiment, the ring magnet portion is axially magnetized, or axial-lateral (AL) magnetized, or tangentially magnetized, and thus is not radially magnetized.

[0089] In an embodiment, the ring magnet portion is radially magnetized.

[0090] In an embodiment, the ring magnet portion has a single track of alternating magnetic poles.

[0091] In an embodiment, the number of pole pairs of the ring magnet portion is an even number.

[0092] This means that the number of magnetic poles on the ring magnet visible by the second sensor group is an integer multiple of four, (in the example of FIG. 1, the number of pole pairs is 6, and the number of magnetic poles is 6x2=12, which is an integer multiple of 4).

[0093] This offers the advantage that the magnetic field seen by the inner magnet portion is symmetrical with respect to the rotation axis. This may be particularly advantageous when the first sensor location measures four out-of-plane components (Bz) from which two magnetic field gradients (dBz / dx) and (dBz / dy) along the first and second direction are determined.

[0094] In an embodiment, the number of pole pairs of the ring magnet portion is an odd number, meaning that the number of poles is a multiple of two but not of four, such as for example 6 or 10 or 14 magnetic poles.

[0095] In an embodiment, the inner magnet portion has a cylindrical shape.

[0096] In an embodiment, the inner magnet portion has a prism shape with a polygonal cross-section, e.g. a square cross section, or a hexagonal cross-section or an octagonal cross section.

[0097] In an embodiment, the outer magnet portion has a ring shape with an inner radius R2 and an outer radius R3, and the ratio (R2 / R3) is a value of at most 60%, or at most 55%, or at most 50%.

[0098] In preferred embodiments, the value (R2 / R3) is a value in the range from 40% to 60%, e.g. equal to about 45%, or equal to about 50%, or equal to about 55%. In an embodiment, the inner magnet portion has a cylindrical shape with a first outer radius Rl, and the outer magnet portion has a ring shape with an inner radius R2 and an outer radius R3; and (R1 / R3) is a value in the range from 15% to 50%; and (R2 / R3) is a value of at most 60%.

[0099] In an embodiment, the inner magnet portion has a cylindrical shape with an outer radius Rl, and the outer magnet portion has a ring shape with an inner radius R2 and an outer radius R3; and (R1 / R3) is a value in the range from 15% to 35%, and (R2 / R3) is a value in the range from 35% to 75%.

[0100] In an embodiment, the inner magnet portion has a cylindrical shape with a first diameter DI, and the outer magnet portion has a ring shape with an inner radius R2 and an outer radius R3 and a single track with a track width tw equal to (tw=R3-R2), and wherein (Dl / tw) is smaller than 150%, or smaller than 140%, or smaller than 130%, or smaller than 120%, or smaller than 110%, or smaller than 100%.

[0101] In an embodiment, the inner magnet portion has a cylindrical shape with a first diameter DI, and the outer magnet portion has a ring shape with an inner radius R2 and an outer radius R3, and a distance "sp" between the inner magnet portion and the outer magnet portion is at most 50% of DI, or at most 40% of DI, or at most 30% of DI.

[0102] In an embodiment, the inner magnet portion as a cylindrical shape with an outer diameter of at most 5.0 mm, or at most 4.5 mm, or at most 4.0 mm, or at most 3.5 mm, or at most 3.0 mm, or at most 2.5 mm, or at most 2.0 mm, or at most 1.5 mm.

[0103] In an embodiment, the ring magnet portion has an outer diameter of at most 12.0 mm, or at most 10.0 mm, or at most 9.0 mm, or at most 8.0 mm.

[0104] In an embodiment, the ring magnet portion has a width (in the radial direction (i.e. a difference between its outer diameter and its inner diameter) in the range from 1.5 mm to 5.0 mm.

[0105] In an embodiment, the inner magnet portion and the outer magnet portion are separated in a radial direction by a distance (e.g. sp) of at most 1.5 mm.

[0106] In an embodiment, the inner magnet portion and the outer magnet portion are separated by a non-ferromagnetic material, e.g. air or aluminum or copper or an aluminum alloy or a copper alloy, etc.

[0107] In an embodiment, one or both of the inner magnet portion and the outer magnet portion comprise or are made of an isotropic magnetic material.

[0108] In preferred embodiments, the magnetic source does not comprise a magnetic shielding between the inner magnet and the outer magnet.

[0109] The inner magnet portion and the outer magnet portion may comprise or can be made of a plastic bonded magnetic material, or ferrite or Neodymium, or FeNdB, or a combination of these.

[0110] According to a third aspect, the present invention also provides an angular position sensor system comprising: a sensor device according to the first aspect; and a magnetic source according to the second aspect; wherein the magnetic source is rotatable about a rotation axis; and wherein the sensor device is mounted such that its first sensor group is facing the inner magnet portion, and the second sensor group is facing the outer magnet portion.

[0111] In an embodiment, the sensor device comprises a non-volatile memory for storing an angular offset value between the inner magnet portion and the outer magnet portion, which value is determined during a calibration procedure; and wherein the absolute angular position (e.g. 9) is determined taking into account the angular offset value stored in the non-volatile memory.

[0112] It is a major advantage that the inner magnet portion and the outer magnet portion do not need to be perfectly aligned during assembly of the magnetic source (as opposed to magnetic sources in which two nonius-tracks are used).

[0113] In an embodiment, the angular position of the inner magnet portion of the magnetic source has a random or pseudo-random angular position relative to the outer magnet portion, and the sensor device has a non-volatile memory holding a value of this angular position which is determined and stored in the non-volatile memory during a calibration procedure. In other words, the inner magnet portion and the outer magnet portion do not have to be perfectly aligned. Such a magnetic source is much easier to produce, because the inner magnet portion and the outer magnet portion can be produced independently, and can then be rotated independently during assembly, without having to align them in a particular direction.

[0114] The system may further comprise an external processor connected to the sensor device, and configured for receiving signals measured by the first sensor group or derived therefrom, and configured for receiving signals measured by the second sensor group or derived therefrom, and configured for determining the absolute angular position (

[0115] In an embodiment, the first sensor group is located substantially on said rotation axis (often referred to as "on-axis"), e.g. as illustrated in FIG. 1A.

[0116] In an embodiment, the first sensor group is located at a non-zero distance from said rotation axis (often referred to as "off-axis"), e.g. as illustrated in FIG. 14, for example at xl=(Rl / 2)±20%, or at xl=(Dl / 4) ±20%. in an embodiment, the magnetic source has an outer diameter in the range from 7.0 mm to 12.0 mm; and a distance (ds) between a geometric centre (gel) of the first sensor group and a geometric centre (gc2) of the second sensor group of the sensor device is a value in the range from 1.0 to 4.0 mm, or in the range from 1.5 to 3.5 mm, or in the range from 2.0 to 3.5 mm.

[0117] In an embodiment, a distance (g) between an upper surface of the magnetic source and the first and second sensor group, is at most 2.0 mm, or at most 1.75 mm, or at most 1.5 mm, or at most 1.2 mm, or at most 1.1 mm, or at most 1.0 mm, or at most 0.9 mm, or at most 0.8 mm, or at most 0.7 mm, or at most 0.6 mm, or at most 0.5 mm.

[0118] It was found that the amplitude of the signals measured by the first / second sensor group are relatively high (e.g. in the order of about 40 mT if g=0.5 mm, or e.g. in the order about about 12 mT if g=1.0 mm), and that a disturbance (cross-talk) from the other (second / first) magnet portion is relatively low when the first sensor group is positioned relatively close to the inner magnet portion. It was very surprising that such a small inner and outer magnet can yield such surprisingly good results.

[0119] Simulations have furthermore shown that the cross-talk between the inner and outer magnet portion is much lower than expected, and is in fact so low, that a magnetic shielding between the inner magnet portion and the outer magnet portion is not required. This is particularly true if the outer magnet portion is axially or tangentially magnetized, and if the inner magnet portion is diametrically magnetized.

[0120] In an embodiment, a diameter DI of the inner magnet portion is smaller than a distance ds between a geometric center (gel) of the first sensor group and a geometric center (gc2) of the second sensor group. Or written in mathematical terms, (e.g. referring to FIG. IB), in this embodiment Dl< ds.

[0121] In an embodiment, the outer magnet portion has a ring shape with an inner radius R2 and an outer radius R3; and a distance ds between a geometric center (gel) of the first sensor group and a geometric center (gc2) of the second sensor group is smaller than an average of R2 and R3, for example at least 5% smaller, or at least 10% smaller or at least 15% smaller, or at least 20% smaller, or at least 25% smaller.

[0122] Or written in mathematical terms, (e.g. referring to FIG. IB), in this embodiment "ds<(R2+R3) / 2, or ds<(R2+R3) / (2*1.05), or ds<(R2+R3) / (2*1.10), or ds<(R2+R3) / (2*1.15), or ds<(R2+R3) / (2*1.20), or ds<(R2+R3) / (2*1.25).

[0123] Stated in every-day language, in this embodiment, the distance "ds" between the sensor locations is smaller than the distance between the center of the inner magnet portion and the center of the track of the ring magnet. A smaller distance "ds" means a smaller chip (package), and also means that the two sensor groups may be implemented on a single semiconductor substrate, while being an economically viable solution. This is especially true if ds < 3.0 mm, or ds < 2.8 mm, or ds < 2.7 mm, or ds < 2.5 mm, or ds < 2.4 mm, or ds < 2.3 mm, or ds < 2.2 mm, or ds < 2.1 mm, or ds < 2.0 mm. The inventors are of the opinion that this is not a trivial solution, especially (1) without a shielding between the magnets, (ii) when the ring magnet has only a single track, in view of expected cross-talk.

[0124] According to a fourth aspect, the present invention also provides an electrical motor comprising: a motor housing; and a shaft rotatable relative to the housing; a magnetic source according to the second aspect fixedly mounted to the shaft; a sensor device according to the first aspect, fixedly mounted to the housing, such that the first sensor group is positioned near an end of the shaft, and is facing the magnetic dipole, and such that the second sensor group is positioned near the ring magnet and facing the magnetic poles of the multipole ring magnet.

[0125] According to a fifth aspect, the present invention also provides a sensor device for determining an absolute angular position of said device relative to a magnetic source having an inner magnet portion in the form of a magnetic dipole, and an outer magnet portion in the form of a multipole ring magnet, wherein the sensor device comprises at least one semiconductor substrate defining a first and a second direction (e.g. X, Y) parallel to the semiconductor substrate, and a third direction (e.g. Z) perpendicular to the semiconductor substrate; the sensor device comprising: a first sensor group for measuring a first set of at least two magnetic field components or at least two magnetic field differences or gradients at a first sensor location (e.g. gel); a second sensor group for measuring a second set of at least two magnetic field components or at least two magnetic field differences or gradients at a second sensor location (e.g. gc2); a third sensor group for measuring a third set of at least two magnetic field components or at least two magnetic field differences or gradients at a third sensor location (e.g. gc3); wherein the first sensor location (e.g. gel) is located at a centre of a virtual circle, and the second and third sensor location (e.g. sg2, sg3) are located at two different positions on said circle, angularly spaced apart by 180° or by 90°; output means for outputting the first and second and third set of signals, or one or more signals derived therefrom.

[0126] Examples of this embodiment are shown in FIG. 22 to FIG. 25.

[0127] In an embodiment, the sensor device calculates and outputs the absolute angular position.

[0128] In a further or another embodiment, the sensor device outputs signals for allowing the determination of the absolute angular position (e.g. 0) by an external processor.

[0129] In an embodiment, the sensor device is a single packaged semiconductor device (or "chip"), optionally comprising a lead frame.

[0130] In an embodiment, the sensor device is implemented as a Wafer-Level-Packaged (WLP) device, comprising three semiconductor substrates, e.g. comprising three CMOS substrates.

[0131] In an embodiment, the sensor device is a printed circuit board comprising two or three packaged devices, together comprising said first, second and third sensor group.

[0132] In an embodiment, the first sensor group (e.g sgl) is configured for measuring at least one of the following: i) at least two or three orthogonal magnetic field components (e.g. Bx, By; By, Bz); ii) a magnetic field component (e.g. Bx) oriented in the first direction (e.g. X) and a magnetic field component (e.g. By) oriented in the second direction (e.g. Y); iii) a magnetic field component (e.g. By) oriented in the second direction (e.g. Y) and a magnetic field component (e.g. Bz) oriented in the third direction (e.g. Z); iv) at least three orthogonal magnetic field components (e.g. Bx, By, Bz); v) at least three magnetic field components (e.g. Bzl, Bz2, Bz3) oriented in the third direction (e.g. Z); vi) at least four magnetic field components (e.g. Bzl, Bz2, Bz3, Bz4) oriented in the third direction (e.g. Z); vii) at least two magnetic field differences or two magnetic field gradients (e.g. dBz / dx, dBz / dy).

[0133] In an embodiment, the first sensor group is configured for measuring: at least two or three orthogonal magnetic field components (e.g. Bx, By; By, Bz), e.g. three orthogonal components measured at a single sensor location, e.g. as illustrated in FIG. 2A to FIG. 2C; or e.g. two orthogonal components measured at a single sensor location, e.g. as illustrated in FIG. 3A to FIG. 3E; or e.g. at least two in-plane components oriented in orthogonal directions, measured at different sensor locations located on a virtual circle or virtual ellipse, e.g. as illustrated in FIG. 11. In an embodiment, the first sensor group is configured for measuring: a magnetic field component (e.g. Bx) oriented in the first direction (e.g. X) and a magnetic field component (e.g. By) oriented in the second direction (e.g. Y), e.g. as illustrated in FIG. 3D, FIG. 3E, FIG. 10, FIG. 11.

[0134] In an embodiment, the first sensor group is configured for measuring: a magnetic field component (e.g. By) oriented in the second direction (e.g. Y) and a magnetic field component (e.g. Bz) oriented in the third direction (e.g. Z), e.g. as illustrated in FIG. 3A to FIG. 3C.

[0135] In an embodiment, the first sensor group is configured for measuring: three orthogonal magnetic field components (e.g. Bx, By, Bz), e.g. as illustrated in FIG. 2A to FIG. 2C.

[0136] In an embodiment, the first sensor group is configured for measuring: three magnetic field components (e.g. Bzl, Bz2, Bz3) oriented in the third direction (e.g. Z), e.g. three components Bzl to Bz3 in three sensor locations located on a virtual circle, spaced apart by multiples of 90°, e.g. as illustrated in FIG. 10; or e.g. three components Bzl to Bz3 in three sensor locations located on a virtual circle, spaced apart by multiples of 120°, e.g. as illustrated in FIG. 4C; or e.g. six components Bzl to Bz6 in six sensor locations located on a virtual circle, spaced apart by multiples of 60°.

[0137] In an embodiment, the first sensor group is configured for measuring: at least four magnetic field components (e.g. Bzl, Bz2, Bz3, Bz4) oriented in the third direction (e.g. Z), e.g. four components Bzl to Bz4 in four sensor locations located on a virtual circle or vertical ellipse, spaced apart by multiples of 90° , e.g. as illustrated in FIG. 4A.

[0138] In an embodiment, the first sensor group is configured for measuring: at least two magnetic field differences or two magnetic field gradients, e.g. two out-of-plane gradients dBz / dx and dBz / dx, e.g. as illustrated in FIG. 4A; or e.g. two pairwise differences Bzl2, Bz23, Bz31, e.g. as illustrated in FIG. 4C.

[0139] In an embodiment, each of the second and third sensor group (e.g. sg2, sg3) are configured for measuring one of the following: i) at least two orthogonal magnetic field components (e.g. By2, Bz2); ii) a magnetic field component (e.g. By) oriented in the second direction or in the a radial direction (e.g. Y) and a magnetic field component (e.g. Bz) oriented in the third direction (e.g. Z); iii) at least three magnetic field components (e.g. Bzl, Bz2, Bz3) oriented in the third direction (e.g. Z); iv) at least three magnetic field components (e.g. Byl, By2, By3) oriented in the second direction (e.g. Y) or in a radial direction; v) at least three magnetic field components (e.g. Bxl, Bx2, Bx3) oriented in the first direction (e.g. X) or in a tangential direction; vi) at least two sets of two orthogonal magnetic field components (e.g. By2,Bz2; By3,Bz3); vii) at least two sets of three orthogonal magnetic field components (e.g. Bx2,By2,Bz2; Bx3,By3,Bz3); viii) at least two magnetic field differences (e.g. diffl, diff2) or two magnetic field gradients (e.g. dBy / dy, dBz / dy; dBx / dy, dBz / dy).

[0140] In an embodiment, the second and third sensor group have identical sensor structures, but are shifted and optionally rotated over 180° (e.g. as in FIG. 23) about the Z-axis.

[0141] In an embodiment, the second and third sensor group have identical sensor structures, but are shifted and rotated over 90° (e.g. as in FIG. 25) about the Z-axis. In an embodiment (not shown), the second and third sensor group have different sensor structures.

[0142] In an embodiment, one or both of the second and third sensor group is configured for measuring: at least two orthogonal magnetic field components (e.g. By2, Bz2), e.g. as illustrated in FIG. 3A to FIG. 3C or FIG. 5B.

[0143] In an embodiment, one or both of the second and third sensor group is configured for measuring: a magnetic field component (e.g. By) oriented in the second direction (e.g. Y) and a magnetic field component (Bz) oriented in the third direction (Z), e.g. as illustrated in FIG. 3A to FIG. 3C.

[0144] In an embodiment, one or both of the second and third sensor group is configured for measuring: at least three magnetic field components (e.g. Bzl, Bz2, Bz3) oriented in the third direction (Z), e.g. three components Bzl, Bz2, Bz3 in three sensor locations spaced apart in the second direction (Y), for example on a virtual line, e.g. as illustrated in FIG. 9.

[0145] In an embodiment, one or both of the second and third sensor group is configured for measuring: at least three magnetic field components (e.g. Byl, By2, By3) oriented in the second direction (Y), e.g. three components Byl, By2, By3 in three sensor locations spaced apart in the second direction (Y), for example on a virtual line, e.g. as illustrated in FIG. 11.

[0146] In an embodiment, one or both of the second and third sensor group is configured for measuring: at least three magnetic field components (e.g. Bxl, Bx2, Bx3) oriented in the first direction

[0147] (X), e.g. three components Bxl, Bx2, Bx3 in three sensor locations spaced apart in the second direction

[0148] (Y), optionally located on a virtual line, e.g. described as a variant of FIG. 9 to FIG. 11;

[0149] In an embodiment, one or both of the second and third sensor group is configured for measuring: at least two sets of two orthogonal magnetic field components (e.g. By2, Bz2), e.g. as illustrated in FIG. 4B or FIG. 4D to FIG. 4F.

[0150] In an embodiment, one or both of the second and third sensor group is configured for measuring: at least two sets of three orthogonal magnetic field components (e.g. Bx2,By2,Bz2; e.g. Bx3,By3,Bz3), e.g. as illustrated in FIG. 4G and FIG. 4H.

[0151] In an embodiment, one or both of the second and third sensor group is configured for measuring: at least two magnetic field differences (e.g. diffl, diff2) or two magnetic field gradients (e.g. dBy / dy, dBz / dy; e.g. dBx / dy, dBz / dy).

[0152] In an embodiment, at least one or at least two of the first, second and third sensor group comprises an integrated magnetic concentrator (IMC) and a plurality of horizontal Hall elements arranged near a periphery of that integrated magnetic concentrator.

[0153] In an embodiment, each of the first, second and third sensor group comprises an integrated magnetic concentrator (IMC) and a plurality of horizontal Hall elements arranged near a periphery of a corresponding integrated magnetic concentrator. In an embodiment, at least one or at least two of the first, second and third sensor group comprises at least two Hall elements without an integrated magnetic concentrator (IMC).

[0154] In an embodiment, each of the first, second and third sensor group comprises at least two Hall elements without an integrated magnetic concentrator (IMC).

[0155] In an embodiment, the absolute angular position (e.g. 91) is determined by: a) determining a coarse signal (e.g. a) based on the signals obtained from the first sensor group sgl (e.g. as described in FIG. 5A to FIG. 11); b) determining a first fine signal (e.g. (32) based on the signals obtained from the second sensor group sg2 (e.g. as described in FIG. 5A to FIG. 11); c) determining a second fine signal (e.g. 3) based on the signals obtained from the third sensor group sg3 (e.g. similar to those described in FIG. 5A to FIG. 11, optionally taking into account said 180° or 90° rotation); d) determining the absolute angular position (e.g. 91) based on the coarse signal (e.g. a) and based on an average (e.g. 0avg) of the first and second fine signal (e.g. 02, 03).

[0156] These method steps may be performed by a processing circuit of the sensor device itself, or by an external processor connected to the sensor device.

[0157] This first technique may be particularly useful for a sensor device (e.g. as illustrated in FIG. 22 and FIG. 23) wherein the second and third sensor group are located above the outer magnet portion at locations angular spaced by 180°, in combination with a magnet assembly having 4N or (4N+2) magnetic poles facing the sensor device, N being an integer.

[0158] This first technique may also be particularly useful for a sensor device (e.g. as illustrated in FIG. 24 and FIG. 25) wherein the second and third sensor group are located above the outer magnet portion at locations angular spaced by 90°, in combination with a magnet assembly having 8N or (8N+4) magnetic poles facing the sensor device, N being an integer.

[0159] The absolute angular position 91 thus determined may have an improved signal-to-noise ratio (SNR), a reduced sensitivity to mounting offset, eccentricity, magnet imperfections, manufacturing tolerances of the sensor device and / or the magnet assembly, vibrations, or combinations hereof.

[0160] In an embodiment, the absolute angular position (e.g. 92) is determined by: a) determining a coarse signal (e.g. a) based on the signals obtained from the first sensor group sgl (e.g. as described in FIG. 5A to FIG. 11); b) determining a fine signal (e.g. 0sum) based on a first and a second sum (e.g. suml, sum2) of magnetic field components obtained from the second and third sensor group (e.g. similar to those described in FIG. 5A to FIG. 11, optionally taking into account said 180° or 90° rotation of the third sensor group); c) determining the absolute angular position (e.g. 92) based on the coarse signal (e.g. a) and based on the fine signal (e.g. 0sum).

[0161] These method steps may be performed by a processing circuit of the sensor device itself, or by an external processor connected to the sensor device.

[0162] This second technique may be particularly useful for a sensor device (e.g. as illustrated in FIG. 22 and FIG. 23) wherein the second and third sensor group are located above the outer magnet portion at locations angular spaced by 180°, in combination with a magnet assembly having 4N magnetic poles facing the sensor device, N being an integer.

[0163] This second technique may also be particularly useful for a sensor device (e.g. as illustrated in FIG. 24 and FIG. 25) wherein the second and third sensor group are located above the outer magnet portion at locations angular spaced by 90°, in combination with a magnet assembly having 8N magnetic poles facing the sensor device, N being an integer.

[0164] The absolute angular position 92 thus determined may have an improved signal-to-noise ratio (SNR), a reduced sensitivity to mounting offset, eccentricity, magnet imperfections, manufacturing tolerances of the sensor device and / or the magnet assembly, vibrations, or combinations hereof.

[0165] In an embodiment, the absolute angular position (e.g. 93) is determined by: a) determining a coarse signal (e.g. a) based on the signals obtained from the first sensor group (e.g. as described in FIG. 5A to FIG. 11); b) determining a fine signal (e.g. (Bdiff) based on a first and a second difference (e.g. diffl, diff2) of magnetic field components obtained from the second and third sensor group (e.g. similar to those described in FIG. 5A to FIG. 11, optionally taking into account said 180° or 90° rotation of the third sensor group); c) determining the absolute angular position (e.g. 93) based on the coarse signal (e.g. a) and based on the fine signal (e.g. (Bdiff).

[0166] These method steps may be performed by a processing circuit of the sensor device itself, or by an external processor connected to the sensor device.

[0167] This third technique may be particularly useful for a sensor device (e.g. as illustrated in FIG. 22 and FIG. 23) wherein the second and third sensor group are located above the outer magnet portion at locations angular spaced by 180°, in combination with a magnet assembly having (4N+2) magnetic poles facing the sensor device, N being an integer.

[0168] This third technique may also be particularly useful for a sensor device (e.g. as illustrated in FIG. 24 and FIG. 25) wherein the second and third sensor group are located above the outer magnet portion at locations angular spaced by 90°, in combination with a magnet assembly having (8N+4) magnetic poles facing the sensor device, N being an integer.

[0169] The absolute angular position 93 thus determined may have an improved signal-to-noise ratio (SNR), a reduced sensitivity to mounting offset, eccentricity, magnet imperfections, manufacturing tolerances of the sensor device and / or the magnet assembly, vibrations, or combinations hereof, and in case the second and third sensor group are angularly spaced by 180° also having a reduced sensitivity to an external disturbance field.

[0170] According to a sixth aspect, the present invention also provides an angular position sensor system comprising: a sensor device according to the fifth aspect; a magnetic source according to the second aspect; wherein the magnetic source is rotatable about a rotation axis; and wherein the sensor device is mounted such that its first sensor group is facing the inner magnet portion, and the second and the third sensor group are facing the outer magnet portion. In an embodiment, the sensor device comprises a non-volatile memory for storing an angular offset value between the inner magnet portion and the outer magnet portion, which value is determined during a calibration procedure; and wherein the absolute angular position is determined taking into account the angular offset value stored in the non-volatile memory.

[0171] According to a seventh aspect, the present invention also provides an electrical motor comprising: a motor housing; a shaft rotatable relative to the housing; a magnetic source according to the second aspect fixedly mounted to the shaft; a sensor device according to the fifth aspect, fixedly mounted to the housing, such that the first sensor group is positioned near an end of the shaft, and is facing the magnetic dipole, and such that the second and the third sensor group are positioned near the ring magnet and facing the outer magnet portion.

[0172] According to an eighth aspect, the present invention also provides a method of determining an angular position of a sensor device according to the fifth aspect relative to a magnetic source according to the second aspect, as may be performed by a processing circuit inside the sensor device, or by a processor communicatively connected to the sensor device, the method comprising the method steps described above, in the "first, second or third technique".

[0173] Particular and preferred aspects of the present invention are set out in the accompanying independent and dependent claims. Features from the dependent claims may be combined with features of the independent claims and with features of other dependent claims as appropriate and not merely as explicitly set out in the claims.

[0174] These and other aspects of the invention will be apparent from and elucidated with reference to the embodiment(s) described hereinafter.

[0175] Brief description of the drawings

[0176] FIG. 1A shows an illustrative example of an angular position sensor system comprising a magnetic source and an angular position sensor device, proposed by the present invention. The magnetic source comprises an inner magnet portion in the form of a magnetic dipole, and an outer magnet portion in the form of a ring magnet.

[0177] FIG. IB shows a cross-section in a plane A-A of FIG. 1A, for a magnetic source comprising a diametrically magnetized dipole, and an axially magnetized ring magnet having a single track and having an odd number of pole pairs.

[0178] FIG. 1C shows a cross-section in a plane A-A of FIG. 1A, for a magnetic source comprising a diametrically magnetized dipole, and an axially magnetized ring magnet having a single track and having an even number of pole pairs.

[0179] FIG. ID and FIG. IE show examples of magnetic dipoles having a cylindrical shape, as may be used in embodiments of the present invention.

[0180] FIG. IF to FIG. 1H show examples of multipole ring-magnets, as may be used in embodiments of the present invention. FIG. 2A to FIG. 2C show illustrative examples of magnetic sensor structures known as "3D magnetic pixels", which may be used in embodiments of the present invention.

[0181] FIG. 3A to FIG. 3E show illustrative examples of magnetic sensor structures known as "2D magnetic pixels", which may be used in embodiments of the present invention.

[0182] FIG. 4A to FIG. 4H show illustrative examples of magnetic sensor structures capable of measuring at least two magnetic field differences or at least two magnetic field gradients, as may be used in embodiments of the present invention.

[0183] FIG. 5A to FIG. 11 show illustrative examples of sensor devices having various sensor arrangements as may be used in embodiments of the present invention.

[0184] FIG. 12 and FIG. 13 are illustrative examples of high-level block-diagrams of sensor devices or sensor systems according to embodiments of the present invention.

[0185] FIG. 14 shows an illustrative example of another angular position sensor system, proposed by the present invention.

[0186] FIG. 15 and FIG. 16 show illustrative examples of sensor devices having particular sensor arrangements as may be used in embodiments of the present invention.

[0187] FIG. 17A to FIG. 17F are illustrative examples of magnetic sources that may be used in embodiments of the present invention.

[0188] FIG. 18 and FIG. 19 shows a simulation of the three orthogonal magnetic field components of the combined (super-imposed) magnetic fields generated by the inner magnet portion and the outer magnet portion of the magnetic source of FIG. 17B, measured at 0.5 mm distance above the centre of the inner magnet portion (FIG. 18), and measured at 0.5 mm distance above a centreline of the outer magnet portion (FIG. 19) respectively.

[0189] FIG. 20 and FIG. 21 shows a simulation of the three orthogonal magnetic field components of the combined (super-imposed) magnetic fields generated by the inner magnet portion and the outer magnet portion of the magnetic source of FIG. 17B, measured at 1.0 mm distance above the centre of the inner magnet portion (FIG. 20), and measured at 1.0 mm distance above a centreline of the outer magnet portion (FIG. 21) respectively.

[0190] FIG. 22A to FIG. 22C show an illustrative example of another angular position sensor system, proposed by the present invention, comprising a first sensor group above the inner magnet portion, and a second and a third sensor group above the ring magnet, diametrically opposite each other.

[0191] FIG. 22A to FIG. 22C can be jointly referred to as FIG. 22.

[0192] FIG. 23 shows an illustrative example of a sensor device that can be used in FIG. 22.

[0193] FIG. 24A to FIG. 24C show an illustrative example of another angular position sensor system, proposed by the present invention, comprising a first sensor group above the inner magnet portion, and a second and a third sensor group above the ring magnet, angularly spaced apart by 90°.

[0194] FIG. 24A to FIG. 24C can be jointly referred to as FIG. 24. FIG. 25 shows an illustrative example of a sensor device that can be used in FIG. 24.

[0195] The drawings are only schematic and are non-limiting. In the drawings, the size of some of the elements may be exaggerated and not drawn on scale for illustrative purposes. Any reference signs in the claims shall not be construed as limiting the scope. In the different drawings, the same reference signs refer to the same or analogous elements.

[0196] Detailed description of illustrative embodiments

[0197] The present invention will be described with respect to particular embodiments and with reference to certain drawings but the invention is not limited thereto but only by the claims. The drawings described are only schematic and are non-limiting. In the drawings, the size of some of the elements may be exaggerated and not drawn on scale for illustrative purposes. The dimensions and the relative dimensions do not correspond to actual reductions to practice of the invention.

[0198] Furthermore, the terms first, second and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequence, either temporally, spatially, in ranking or in any other manner. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other sequences than described or illustrated herein.

[0199] Moreover, the terms top, under and the like in the description and the claims are used for descriptive purposes and not necessarily for describing relative positions. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other orientations than described or illustrated herein.

[0200] It is to be noticed that the term "comprising", used in the claims, should not be interpreted as being restricted to the means listed thereafter; it does not exclude other elements or steps. It is thus to be interpreted as specifying the presence of the stated features, integers, steps or components as referred to, but does not preclude the presence or addition of one or more other features, integers, steps or components, or groups thereof. Thus, the scope of the expression "a device comprising means A and B" should not be limited to devices consisting only of components A and B. It means that with respect to the present invention, the only relevant components of the device are A and B.

[0201] Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment, but may. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments. Similarly, it should be appreciated that in the description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this invention.

[0202] Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form different embodiments, as would be understood by those in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination.

[0203] Furthermore, the terms "approximately", "substantially", or "about" indicate a range of tolerance which the skilled person in the field in question considers to be normal. In particular, the aforementioned terms are to be understood as encompassing a tolerance range of the referred quantity of up to a maximum of ±20 %, preferably up to a maximum of ±10 %, unless explicitly mentioned otherwise, or unless clear from the context otherwise.

[0204] In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the invention may be practiced without these specific details. In other instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.

[0205] In this document, the expressions "magnetic source" or "magnet assembly" mean the same. In the context of the present invention, the magnetic source comprises an inner magnet portion in the form of a magnetic dipole, and an outer magnet portion in the form of a ring magnet.

[0206] In this document, unless explicitly mentioned otherwise, the term "magnetic sensor device" or "sensor device" refers to a device comprising a plurality of "magnetic sensors" or "magnetic sensor elements", preferably integrated in a single semiconductor substrate, or in two semiconductor substrates comprised in a single package, together forming a "packaged semiconductor device", also called "chip". The package may be formed by a plastic or a ceramic moulding compound.

[0207] In this document, the term "sensor element" or "magnetic sensor element" or "magnetic sensor" can refer to a component or a group of components or a sub-circuit or a structure capable of measuring a magnetic quantity, such as for example a magneto-resistive (MR) element, an AMR element, a GMR element, an XMR element, a TRM element, a horizontal Hall plate, a vertical Hall plate, a Wheatstone-bridge containing at least one (but preferably four) magneto-resistive elements, etc. or combinations hereof.

[0208] In the present invention, the expression "magnetic sensor group" or "magnetic sensor structure" or "magnetic sensor arrangement" refers to a group of at least two magnetic sensor elements, and optionally one or more integrated magnetic concentrators (IMC).

[0209] In this document, the expression "in-plane component of a magnetic field vector" and "projection of the magnetic field vector in the sensor plane" mean the same. If the sensor device is or comprises a substrate, this also means "magnetic field component parallel to the substrate". These components are typically referred to as Bx, By.

[0210] In this document, the expression "out-of-plane component of a vector" and "Z component of the vector" and "projection of the vector on an axis perpendicular to the sensor plane" mean the same. This component is typically referred to as Bz.

[0211] In this document, the word "magnet", "magnet assembly", "magnetic structure" and "magnetic source" are used as synonyms, unless clear from the context that something else is meant.

[0212] Embodiments of the present invention are typically described using an orthogonal coordinate system which is fixed to the sensor device, and having three axes X, Y, Z, where the X and Y axis are parallel to the substrate, and the Z-axis is perpendicular to the substrate. If the sensor device comprises more than one substrate, these substrates are preferably oriented in parallel.

[0213] Furthermore, in embodiments of the present invention, the sensor device is preferably oriented relative to the magnetic source such that the X-axis of the sensor device is oriented in a radial direction of the magnetic source, and such that the Z-axis of the sensor device is oriented in the axial direction of the magnetic source.

[0214] In this document, the expression "spatial derivative" or "derivative" or "spatial gradient" or "gradient" are used as synonyms. In the context of the present invention, a magnetic field gradient (e.g. dBz / dx) of a magnetic field component (e.g. Bz) along the X-direction, is determined as a difference ABz between the values of two magnetic field components (e.g. Bzl, Bz2) oriented in the Z-direction, measured at two sensor locations (e.g. xl, x2) spaced apart in the X-direction. In theory a gradient is calculated as the difference between two values divided by the distance "dx" between the sensor locations, but in practice the division by "dx" is often omitted, because the measured signals need to be scaled anyway. Hence, in the context of the present invention, the magnetic field difference (ABx) and magnetic field gradient dBx / dx may be used interchangeably.

[0215] In this document, the term "magnitude of a magnetic field component By" means "the maximum of the absolute value of the By-signal over a full 360° (electrical) rotation of the magnet", and likewise for "amplitude of Bx" and "amplitude of Bz".

[0216] In this application, horizontal Hall plates are typically referred to by Hl, H2, etc., signals from these horizontal Hall plates are typically referred to by hl, h2, etc.; vertical Hall plates are typically referred to by VI, V2, etc.; and signals from these vertical Hall plates are typically referred to by vl, v2, etc.

[0217] In the context of the present invention, the formulas arctan(x / y), atan2(x,y), arccot(y / x) are considered to be equivalent.

[0218] In this application, the expression "the sensor group is located at a particular location" means that a central position of that sensor group, also referred to herein as "geometric centre" of that sensor group is located at the specified location.

[0219] In this application, the term "track" as part of a ring magnet, refers to a planar surface of the ring magnet. The track of the ring magnet has a width or "track width "tw" extending in the radial direction of the ring magnet.

[0220] The term "centreline of a track" as used herein refers to a virtual circle, situated in the middle of the track, halfway between the inner radius and the outer radius of the ring magnet.

[0221] In this document, the expression "a sensor group is located vertically above a specified location" means that a vertical projection of a geometric centre of the sensor group is located on said specified location. Unless otherwise specified, the expression "vertical projection" means a projection along the Z-axis.

[0222] In this document, the expression "inner magnet" or "inner magnet portion" or "inner dipole" mean the same.

[0223] In this document, the expression "outer magnet portion" or "ring magnet portion" or "ring magnet" mean the same.

[0224] Referring now to the figures.

[0225] FIG. 1A shows an illustrative example of an angular position sensor system 120 comprising a magnetic source 110 and an angular position sensor device 100.

[0226] The magnetic source 110 has an inner magnet portion 111 in the form of a magnetic dipole, and an outer magnet portion 112 in the form of a multipole ring magnet, fixedly connected to each other, e.g. directly or indirectly.

[0227] The inner magnet portion 111 may be a diametrically magnetized dipole magnet (e.g. as illustrated in FIG. ID), or may be an axially magnetized dipole magnet (e.g. as illustrated in FIG. IE). The magnetic dipole has a periodicity of 360°, thus allows the absolute angle 9 to be measured in a 360° angular range. The inner magnet portion preferably has a cylindrical shape with an outer diameter DI, but that is not absolutely required, and other shapes will also work, such as e.g. a cubical shape, or a prism shape with a polygonal cross-section (e.g. a square, a hexagon, an octagon, etc.).

[0228] The outer magnet portion 112 is a multipole ring magnet. This ring magnet may be a radially magnetized ring magnet (e.g. as illustrated in FIG. IF) having two tracks at its upper surface; or may be an axially magnetized ring magnet (e.g. as illustrated in FIG. 1G) having only a single track at its upper surface; or may be an AL (Axial-Lateral) magnetized ring magnet, also called "arc-shaped" magnetized ring magnet (e.g. as illustrated in FIG. 1H) having only a single track at its upper surface. The ring magnet of FIG. IF and the ring magnet of FIG. 1G have a periodicity of 36074=90°. The ring magnet of FIG. 1H has a periodicity of 360° / 5=72° . In general, the periodicity of the ring magnet is 360° / Npp, where Npp is the number of pole pairs of the single track (see FIG. 1G and FIG. 1G) or of the outer track (see FIG. IF). In preferred embodiments, Npp is at least three (i.e. periodicity = 360° / 3=120°), or at least four (i.e. periodicity = 360° / 4=90°), or at least five (i.e. periodicity = 360° / 5=72°), or at least six (i.e. periodicity = 360° / 6=60°). Referring back to FIG. 1A, the multipole ring magnet 112 allows the absolute angle 9 to be measured with a high resolution, and the magnetic dipole 111 allows the absolute angle 9 to be determined in a 360° range. In embodiments of the present invention, the number of pole pairs Npp of the single track or of the outer track may be an even number (i.e. the number of poles of the single track if there is only one track or of the outer track if there are two tracks, is an integer multiple of 4), or may be an odd number (i.e. the number of poles of the single or outer track is equal to 2 plus an integer multiple of 4).

[0229] In the example shown in FIG. 1A, the inner magnet portion 111 has an outer diameter DI, and the outer magnet portion 112 has an inner diameter D2 and an outer diameter D3, and a track width tw equal to (D3-D2) / 2.

[0230] In the example shown in FIG. 1A, the inner magnet portion 111 is spaced from the outer magnet portion 112 by a spacing "sp", but that is not absolutely required. If present, the spacing may be filled by a non-magnetic material, e.g. by a plastic or aluminum or an aluminum alloy. In a particular embodiment, the inner magnet portion 111 is mounted in an aluminum tubular element (not shown), which in turn is mounted inside the ring magnet portion 112. In this case the spacing is substantially filled with aluminum.

[0231] FIG. 1A also shows a schematic representation of a sensor device 100 having a first sensor group 101 which is situated above the inner magnet portion 111, and having a second sensor group 102 which is situated above the outer magnet portion 112. Both sensor groups are represented by white squares in FIG. 1A, because various sensor structures can be used, e.g. as described further and illustrated in FIG. 2A to FIG. 11, but the present invention is not limited to these examples, but only by the claims. A geometric centre gel of the first sensor group 101 is spaced from a geometric centre gc2 of the second sensor group by a distance "ds".

[0232] In the embodiment of FIG. 1A, the geometric centre gel of the first sensor group 101 is preferably located on the rotation axis, i.e. vertically above the centre of the magnetic source 110, and the geometric centre gc2 of the second sensor group 102 is preferably located vertically above a centreline 114 halfway between the inner diameter and the outer diameter of the ring magnet, but the present invention is not limited hereto, and the second sensor group 102 may also be shifted radially inwards or outwards. In FIG. 14, a variant of the angular position sensor system 120 of FIG. 1A will be shown, wherein the first sensor group 1401 is located off-axis, but above the inner magnet portion 1411. Also here, the second sensor group 1402 may be located on the centreline 1414 (i.e. halfway between the inner diameter D2 and outer diameter D3), or slightly radially inwards or slightly radially outwards, but still above the ring magnet portion 1412.

[0233] In a particular embodiment, DI may be substantially equal to 2.0 mm, and D2 may be substantially equal to 4.0 mm, hence sp=(D4-D2) / 2=l mm, and D3 may be substantially equal to 8.0 mm, and ds may be substantially equal to 3.0 mm, but of course, the present invention is not limited hereto, and other dimensions can also be used.

[0234] In case D3 is larger than 8.0 mm, (D1 / D3) may be substantially equal to 25%, and (D2 / D3) may be substantially equal to 50%, and ds may be substantially equal to D3*(75%).

[0235] It was found that the gap or spacing between the inner magnet portion 111 and the outer magnet portion 112 may be smaller than D3*12,5%, or may even be completely absent. In some embodiments, (D1 / D3) may still be substantially equal to 25%, and (D2 / D3) may be a value in the range from 25% to 50%. In another embodiment, (D1 / D3) and (D2 / D3) may both be chosen in the range from 30% to 40%, e.g. equal to about 35%.

[0236] FIG. IB shows a cross-section of the sensor system 120 of FIG. 1A in a plane A-A, in case the inner magnet portion 111 is a diametrically magnetized dipole having a cylindrical shape, and in case the outer magnet portion 112 is an axially magnetized ring magnet having a single track and an odd number of pole pairs (Npp). As can be seen, this implies that the magnetization direction may be pointing upwards on the left side of FIG. IB, and may be pointing downwards on the right side of FIG. IB (or vice versa).

[0237] FIG. IB also shows the position of the sensor device 100 relative to the magnetic source 110. In the example shown, the geometric centre gel of the first sensor group 101 may be located above the centre of the inner magnet portion 111, and the geometric centre gc2 of the second sensor group 102 may be located above a centreline 114 of the track of the ring magnet 112, but the present invention is not limited to these sensor positions, and the present invention will also work with other sensor positions, e.g. between said centre and said centreline (as will be described further in FIG. 14 to FIG. 16). As can be seen in FIG. IB, the first geometric centre gel and the second geometric centre gc2 are located at a distance "g" above the respective magnet portions 111, 112. In preferred embodiments of the present invention, the distance "g" is at most 2.0 mm, or at most 1.5 mm, or at most 1.4 mm, or at most 1.3 mm, or at most 1.2 mm, or at most 1.1 mm, or at most 1.0 mm, or at most 0.9 mm, or at most 0.8 mm, or at most 0.7 mm, or at most 0.6 mm, or at most 0.5 mm. It is an advantage if the relative heights of the inner magnet portion and the outer magnet portion are the same, because it simplifies assembly of the angular sensor system, since the magnet does not need to be oriented in a particular way.

[0238] FIG. 1C shows a cross-section of the magnetic source 110 of FIG. 1A in a plane A-A, in case the inner magnet portion 111 is a diametrically magnetized dipole having a cylindrical shape, and in case the outer magnet portion 112 is an axially magnetized ring magnet having a single track and having an even number of pole pairs (Npp). As can be seen, in this case the arrows are both oriented upwards (or both downwards), meaning that the magnetization direction on opposite sides of the rotation axis 113 are oriented in the same direction. It was found that choosing a ring magnet with an even number of magnetic pole pairs may reduce the cross-talk experienced by the first sensor group 101 caused by the outer magnet portion 112.

[0239] FIG. ID and FIG. IE show examples of magnetic dipoles having a cylindrical shape, which may be used as the inner magnet portion 111 of FIG. 1A. The dipole of FIG. ID is diametrically magnetized. The dipole of FIG. IE is axially magnetized.

[0240] FIG. IF and FIG. 1G and FIG. 1H show examples of multipole ring-magnets, as may be used in embodiments of the present invention. The ring magnet of FIG. IF is radially magnetized, has two tracks, has 8 pole pairs, and a periodicity of 360° / 4=90°. The ring magnet of FIG. 1G is axially magnetized, has a single track with 4 pole pairs, and also has a periodicity of 36074=90°. The ring magnet of FIG. 1H is AL (Axial-Lateral) magnetized, also referred to as a "ring magnet with rotating front magnetization" and has a single track with 5 pole pairs at its upper surface, but of course, the present invention is not limited to these illustrative examples, and ring magnets with another suitable kind of magnetization (e.g. a laterally magnetized ring magnet) and / or with another number of pole pairs may also be used, such as e.g. five pole pairs or six pole pairs, or seven pole pairs, or eight pole pairs, or ten pole pairs, or twelve pole pairs, or more than twelve pole pairs.

[0241] FIG. 2A to FIG. 2C show illustrative examples of magnetic sensor structures or sensor groups known as "3D magnetic pixels", which may be used in embodiments of the present invention.

[0242] FIG. 2A shows a magnetic structure sg2a comprising a disk shaped integrated magnetic concentrator (IMC) and four horizontal Hall elements Hl to H4 arranged near a periphery of the IMC, angularly spaced by multiples of 90°. This sensor structure sg2a is capable of measuring three orthogonal magnetic field components Bx, By, Bz at the centre of the IMC. A typical size of a Horizontal Hall element is 15 to 25 nm. A typical diameter of a disk-shaped IMC is 150 to 250 nm. The Hall elements Hl to H4 provide signals hl to h4. The value of Bx is proportional to (h4-h3), but since the signals from the Hall sensors need to be scaled anyway, the scaling factor is often omitted, and the formula can be simplified to Bx=(h4-h3). The same reasoning applies also to other magnetic field components, and to signals obtained from vertical Hall elements.

[0243] FIG. 2B shows a sensor group sg2b having a single Horizontal Hall element Hl for measuring Bz, and two vertical Hall elements: VI has its axis of maximum sensitivity oriented in the X-direction for measuring Bx, V2 has its axis of maximum sensitivity oriented in the Y-direction for measuring By. In view of the small size of these sensor elements and the small distance between them (e.g. typically less than 50 nm), it can be assumed in practice that the values of Bx, By, Bz are measured at the same sensor location (e.g. at the centre of the horizontal Hall element Hl).

[0244] FIG. 2C shows a sensor group sg2c having a single Horizontal Hall element Hl for measuring Bz, and two pairs of vertical Hall elements: VI and V3 have their axes of maximum sensitivity oriented in the X-direction; V2 and V4 have their axes of maximum sensitivity oriented in the Y-direction. The signals vl and v3 obtained from VI and V3 can be added or averaged, and yield a value for Bx. Likewise, the signals v2 and v4 obtained from V2 and V4 can be added or averaged, and yield a value for By.

[0245] FIG. 3A to FIG. 3E show illustrative examples of magnetic sensor structures (or sensor groups), also referred to as "2D magnetic pixels", which may be used in embodiments of the present invention.

[0246] FIG. 3A shows a sensor group sg3a comprising a disk shaped integrated magnetic field concentrator (IMC) with two horizontal Hall elements Hl, H2 arranged near a periphery of the IMC, spaced apart by 180°. This sensor group is capable of measuring By and Bz.

[0247] FIG. 3B shows a sensor group sg3b comprising a single horizontal Hall element Hl, and a single vertical Hall element VI with its axis of maximum sensitivity oriented in the Y-direction. This sensor group is capable of measuring By and Bz.

[0248] FIG. 3C shows a sensor group sg3c comprising a single horizontal Hall element Hl and two vertical Hall element VI, V2 located on opposite sides of Hl, both with their axis of maximum sensitivity oriented in the Y-direction. This sensor group sg3c is capable of measuring By and Bz. The signals vl and v2 obtained from Vl and V2 may be added or averaged.

[0249] The sensor groups of FIG. 3A to FIG. 3C are capable of measuring one in-plane component By and one out-of-plane component Bz.

[0250] In a variant (not shown), if the 2D magnetic pixels sg3a to sg3c of FIG. 3A to FIG. 3C are rotated by 90° around the Z-axis, they are capable of measuring one in-plane component Bx and one out-of- plane component Bz.

[0251] FIG. 3D shows a sensor group sg3d comprising two vertical Hall elements Vl and V2, one for measuring Bx, the other for measuring By. FIG. 3E shows a sensor group sg3e comprising four vertical Hall elements VI to V4, two (VI and V3) for measuring Bx, and two (V2 and V4) for measuring By.

[0252] The sensor groups of FIG. 3E and FIG. 3F are capable of measuring two in-plane magnetic field components (Bx and By).

[0253] FIG. 4A to FIG. 4D show illustrative examples of magnetic sensor structures capable of measuring at least two magnetic field differences or at least two magnetic field gradients, as may be used in embodiments of the present invention.

[0254] FIG. 4A shows a sensor group sg4a comprising four horizontal Hall elements Hl to H4, arranged on a virtual circle, typically having a diameter in the range from 600 pm to 1600 pm, or from 800 pm to 1200 pm, e.g. equal to about 1000 pm, spaced apart by multiples of 90°. This sensor group does not comprise an integrated magnetic concentrator. Each of the Hall elements measures an out-of-plane component Bz at respective locations on said circle. This structure or sensor group sg4a allows to determine two magnetic field differences or gradients, namely: a magnetic field difference or gradient of Bz along the X-axis, denoted as ABzx or as dBz / dx, proportional to (h4-h3), and to determine a magnetic field difference or gradient of Bz along the Y-axis, denoted as ABzy or as dBz / dy, proportional to (hl-h2). The subtraction of signals may be performed in the analog domain or in the digital domain. Division by dx or dy can be omitted, because the signals need to be scaled anyway. In other words, the sensor group of FIG. 4A allows to determine two out-of-plane magnetic field gradients.

[0255] FIG. 4B shows a sensor group sg4b comprising two 2D-pixels of the type shown in FIG. 3A, spaced apart in the Y-direction by a distance dy in the order of about 600 pm to 1600 pm, or from 800 pm to 1200 pm, e.g. equal to about 1000 pm. Each of the 2D pixels of the sensor group sg4b of FIG. 4B can also be referred to as a "sensor subgroup". Since each 2D pixel can measure a respective value for By and Bz, the sensor structure sg4b allows to measure or to determine a magnetic field difference or gradient of Bz along the Y-direction, denoted as ABzy or dBz / dy in accordance with the formula (Bzl- Bz2); and a magnetic field difference or gradient of By along the Y-direction, denoted as AByy or dBy / dy in accordance with the formula (Byl-By2). In other words, the sensor group of FIG. 4B allows to determine an in-plane gradient (dBy / dy) and an out-of-plane gradient (dBz / dy) along the Y-direction.

[0256] FIG. 4C shows a sensor group sg4c comprising three horizontal Hall elements arranged on a virtual circle, typically having a diameter in the range from 600 pm to 1600 pm, or from 800 pm to 1200 pm, e.g. equal to about 1000 pm spaced apart by multiples of 120°. This sensor group does not comprise an integrated magnetic concentrator. Each of the Hall elements Hl to H3 measures an out-of-plane component Bz at respective locations on said circle. It is possible to determine three pairwise differences between the measured values. It is also possible to determine (e.g. calculate) a sum or an average of the three signals hl to h3 obtained from the three Hall elements, and / or to subtract the average from each of the individual signals. When placed above the centre of a dipole magnet, these signals behave like three-phase signals, having a same amplitude but 120° phase shifted. These signals may be converted into quadrature signals in manners known in the art (e.g. using the Clarke transformation), and an angular position a can be derived therefrom using an arctangent function.

[0257] In a variant (not shown) of FIG. 4C, the sensor group comprises six horizontal Hall elements instead of three, spaced apart on said circle by multiples of 60°.

[0258] FIG. 4D shows a sensor group sg4d comprising two 2D-pixels of the type shown in FIG. 3C, spaced apart in the Y-direction by a distance dy in the order of about 600 pm to 1600 pm, or from 800 pm to 1200 pm, e.g. equal to about 1000 pm. Each of the 2D pixels of the sensor group sg4d of FIG. 4D can also be referred to as a "sensor subgroup". Since each 2D pixel can measure a respective value for By and Bz, the sensor structure sg4d allows to measure or to determine a magnetic field difference or gradient of Bz along the Y-direction, denoted as ABzy or dBz / dy in accordance with the formula (Bzl- Bz2); and a magnetic field difference or gradient of By along the Y-direction, denoted as AByy or dBy / dy in accordance with the formula (Byl-By2). In other words, the sensor group of FIG. 4D allows to determine an in-plane gradient (dBy / dy) and an out-of-plane gradient (dBz / dy) along the Y-direction. The sensor group of FIG. 4D is functionally equivalent to the sensor group of FIG. 4B.

[0259] In a variant (not shown) of FIG. 4D, one of the vertical Hall elements VI, V2 is omitted and one of the vertical Hall elements V3, V4 is omitted. This sensor group contains two horizontal Hall elements and two vertical Hall elements, and also allows to determine two magnetic field gradients dBy / dy and dBz / dy.

[0260] FIG. 4E shows a sensor group sg4e which is a variant of the sensor group sg4b of FIG. 4B, wherein each of the 2D pixels (or subgroups) is rotated over 90° about the Z-axis. The sensor group sg4e is capable of measuring or determining a magnetic field difference or gradient of the Bx component along the Y-direction, which can be written as ABxy=dBx / dy=(Bxl-Bx2), and a magnetic field difference or gradient of the Bz-component along the Y-direction, which can be written as ABzy=dBz / dy=(Bzl-Bz2).

[0261] FIG. 4F shows a sensor group sg4f which is a variant of the sensor group sg4d of FIG. 4D, wherein each of the 2D pixels (or subgroups) is rotated over 90° about the Z-axis. The sensor group sg4f is capable of measuring or determining a magnetic field difference or gradient of the Bx component along the Y-direction, which can be written as ABxy=dBx / dy=(Bxl-Bx2), and a magnetic field difference or gradient of the Bz-component along the Y-direction, which can be written as ABzy=dBz / dy=(Bzl-Bz2). The sensor group sg4e of FIG. 4E and the sensor group sg4f of FIG. 4F are functionally equivalent. In a variant (not shown) of FIG. 4F, one of the vertical Hall elements VI, V2 is omitted, and one of the vertical Hall elements V3, V4 is omitted. This sensor group is still capable of determining said inplane gradient dBx / dy and said out-of-plane gradient dBz / dy.

[0262] FIG. 4G shows a sensor group sg4g comprising two 3D-pixels of the type shown in FIG. 2A, spaced apart in the Y-direction by a distance dy in the order of about 600 pm to 1600 pm, or from 800 pm to 1200 pm, e.g. equal to about 1000 pm. Each of the 3D pixels of the sensor group sg4g of FIG. 4G can also be referred to as a "sensor subgroup". Since each 3D pixel can measure a respective value for Bx, By and Bz, the sensor structure sg4g allows to measure or to determine three magnetic field differences or gradients along the Y-direction, denoted as ABxy=dBx / dy, AByy=dBy / dy and ABzy=dBz / dy.

[0263] In a variant (not shown), the 3D pixels of the sensor group of FIG. 4G are replaced by two 3D pixels of the type shown in FIG. 2B. This sensor group is also capable of determining said three magnetic field differences or gradients.

[0264] FIG. 4H shows a sensor group sg4h which is another variant of the sensor group of FIG. 4G, wherein each 3D pixel is of the type shown in FIG. 2C, and comprises one horizontal Hall element and four vertical Hall elements. The sensor group sg4h is also capable of determining said three magnetic field differences or gradients dBx / dy, dBy / dy and dBz / dy along the Y-axis.

[0265] FIG. 5A to FIG. 11 show illustrative examples of sensor devices as may be used in embodiments of the present invention, e.g. in the angular position sensor system 120 of FIG. 1A.

[0266] FIG. 5A shows a sensor device 500 comprising a first sensor group sg5a capable of measuring two in-plane magnetic field components, namely Bx, By at a first sensor location, and a second sensor group sg5b capable of measuring an in-plane component By and an out-of-plane component Bz. In the specific example shown in FIG. 5A, the first sensor group is the 3D magnetic pixel of FIG. 2A, but other sensor groups capable of measuring Bx, By can also be used (e.g. any of the sensor groups of FIG. 2B, or FIG. 2C, or FIG. 3D, or FIG. 3E, or sensor groups with MR elements, not shown); and the second sensor group is the 2D magnetic pixel of FIG. 3A, but other sensor groups capable of measuring By, Bz at the second sensor location can also be used (e.g. any of the sensor groups of FIG. 2A to FIG. 2C, or FIG. 3A to FIG. 3C).

[0267] Importantly, the first sensor group sg5a and the second sensor group sg5b of FIG. 5A are incorporated in a single packaged device, also referred to as "chip". The first sensor group sg5a and the second sensor group sg5b may be implemented on a single semiconductor substrate, or may be implemented on two separate semiconductor substrates, which may e.g. be mounted next to each other, for example on a lead frame.

[0268] In another embodiment, the sensor device 500 comprises two or three semiconductor substrates, e.g. CMOS substrates, which are interconnected using one or more redistribution layers (RDL), and the single packaged device is a WLP-package (Wafer-Level-Package). In case the sensor device furthermore comprises a processing circuit (e.g. 1252 of FIG. 12 or 1352a, 1352b of FIG. 13), this processing circuit may be implemented on the same semiconductor die as the first sensor group sg5a or the second sensor group sg5b, or may be implemented on a separate (third) semiconductor substrate different from the first and the second substrate.

[0269] Referring back to FIG. 5A, an accurate value of 9 can be determined over a full 360° angular range based on the signals obtained from the first sensor group sg5a and the second sensor group sg5b. If the sensor device 500 has a processing unit, the angular position 9 may be calculated in the chip itself (as will be explained further in FIG. 12), but it is also possible that the sensor device 500 outputs the measured signals, or signals derived therefrom, e.g. one or more magnetic field components, one or more magnetic field differences, one or more magnetic field gradients, as analog or digital values, or a ratio of these values, or a function of said ratio, e.g. an arctangent value of such a ratio.

[0270] In a particular embodiment, the sensor device 500 further comprises a processing unit (e.g. 1252 of FIG. 12 or 1352a, 1352b of FIG. 13), and the processing unit is configured for calculating a first angle a based on the signals obtained from the first sensor group sg5a, and is further configured for determining a second angle [3 based on the signals obtained from the second sensor group sg5b, and is further configured for determining the absolute angular position 9 based on the first angle a and the second angle [3. For example, the angle [3 may be divided by Npp to obtain a fine angle value to which a sector-offset is added, equal to M*(360° / Npp), where M is an integer value, sometimes referred to as "sector-count", which can be derived from the first angle a, optionally in combination with the second angle [3. Several variants of this algorithm are possible. For example, the sector-count can also be derived by determining a first ratio "Rl" of the two in-plane components Bxl, Byl measured by the first sensor group, and by comparing this value of Rl with a limited number of threshold-values, without having to calculate the actual angle a. The number of threshold values, and their numerical values may depend on the number of pole pairs of the multipole magnet, and be stored in a non-volatile memory of the sensor device. A second ratio R2 may be calculated of By2 and Bz2 measured by the second sensor group.

[0271] In the particular example shown in FIG. 5A, the first sensor group sg5a is a 3D magnetic pixel, hence is also capable of measuring Bzl, e.g. as (hl+h2) or as (h3+h4) or as (hl+h2+h3+h4). The value of Bzl is not required for determining the angle a or 9, but may be used for other purposes, for example for diagnostics or error-detection purposes.

[0272] The sensor device 500 may be configured to output one or more of the values Bxl, Byl, Bzl, By2, Bz2, Rl, R2, a, [3, 9, and / or other signals derived therefrom, such as e.g. a sector-count (derived from a), or sector-offset angle e.g. calculated as sector-count * (360° / Npp), or a fine angle calculated as (|3 / Npp). As mentioned above, the absolute angle 9 may also be calculated outside of the sensor device (e.g. as illustrated in FIG. 13). The sensor device 500 is particularly suited for use in combination with a magnetic source as illustrated in FIG. 1A, especially if the inner magnet portion is diametrically magnetized (e.g. as in FIG. ID), and if the outer magnet portion is axially magnetized (e.g. as in FIG. 1G) or magnetized as shown in FIG. 1H, but other magnetic sources may also be used.

[0273] As can be seen, the sensor device 500 comprises two IMC-disks, and six horizontal Hall elements. While the value of 9 can be determined with high accuracy (e.g. better than 10 bits) over a large temperature range (e.g. from -20°C to +120°C, or from -40°C to +160°C), the value of a and are sensitive to a magnetic disturbance field, hence also the value of 9 is sensitive to an external disturbance field.

[0274] FIG. 5B shows a sensor device 550, which can be seen as a variant of the sensor device 500 of FIG. 5A, where the second sensor group is rotated by 90° about the Z-axis. The sensor device 550 of FIG. 5B is particularly suited for use in combination with a magnetic source as illustrated in FIG. 1A, where the inner magnet portion 111 is diametrically magnetized (e.g. as illustrated in FIG. ID), and the outer magnet portion 112 is radially magnetized (e.g. as illustrated in FIG. IF). Everything else mentioned above for the sensor device 500 of FIG. 5A is also applicable here, mutatis mutandis.

[0275] FIG. 5C shows a sensor device 560, which can be seen as another variant of the sensor device 500 of FIG. 5A, and which is functionally equivalent. As can be seen, the first sensor group sg5e comprises a horizontal Hall element Hl and four vertical Hall elements VI to V4 but no IMC, and the second sensor group sg5f comprises a horizontal Hall element H2 and two vertical Hall elements V5 and V6. Everything else mentioned above for the sensor device 500 of FIG. 5A is also applicable here, mutatis mutandis.

[0276] In a variant (not shown) of FIG. 5C, the second sensor group sg5f is rotated by 90° about the Z- axis. This sensor device is functionally equivalent to the sensor device 550 of FIG. 5B.

[0277] FIG. 5D shows a sensor device 570, which can be seen as a variant of the sensor device 560 of FIG. 5C without the first horizontal Hall element Hl, which is not absolutely required.

[0278] In a variant (not shown) of FIG. 5D, the second sensor group sg5h is rotated by 90° about the Z-axis. Such sensor device is functionally equivalent to the sensor device 550 of FIG. 5B, if Bzl is not used.

[0279] FIG. 5E shows a sensor device 580, which can be seen as another variant of the sensor device 500 of FIG. 5A, wherein the second sensor group sg5j is also a 3D magnetic pixel, and thus furthermore capable of measuring Bx2 at the second sensor location gc2. The value of Bx2 is not absolutely required in combination with an axially magnetized ring magnet portion 112, but may be used for diagnostic purposes or error detection purposes (e.g. to detect a mismatch between ds and the magnetic source, and / or to detect that the sensor device 580 is spaced too far from the magnetic source, and / or to detect that the radial position of the sensor device is incorrect). On the other hand, this sensor device 580 with the sensor groups sg5i and sg5j can be used in combination with a magnetic source having a radially magnetized ring magnet portion 112 (see e.g. FIG. IF), in which case the values of Bx2 and Bz2 are needed for determining the second angle , but the value of By2 is optional, and may be used for diagnostics or error detection purposes. It is advantageous that the same hardware of the sensor device 580 can be used with different types of magnetic sources. Depending on the application, the sensor devices may be configured differently (e.g. for outputting certain component values, but not others), and / or may be configured for running different firmware stored in a non-volatile memory.

[0280] In a particular embodiment, the second sensor group sg5j is configured for measuring the three magnetic field component values Bx2, By2, Bz2, and is further configured for automatically detecting whether the ring magnet portion 112 is axially magnetized or radially magnetized, e.g. by determining a norm or magnitude of the magnetic field (e.g. as the square root of a sum of squares of the three magnetic field components Bx2, By2, Bz2), and by testing which of the components has an amplitude that is at least a factor of 2 smaller than the other two components, and if the component with the smallest amplitude is Bx2 to decide that the ring magnet portion is axially magnetized, and if the component with the smallest amplitude is By2, to decide that the ring magnet portion is radially magnetized.

[0281] FIG. 5F shows a sensor device 590, which is functionally equivalent with the sensor device 580 of FIG. 5E, but uses sensor groups with horizontal Hall elements and vertical Hall elements, without integrated magnetic concentrators (IMC). As can be seen, each of the first and second sensor group sg5k, sg5m contains one horizontal Hall element and four vertical Hall elements.

[0282] Looking back, it can be seen that the sensor devices of FIG. 5A to FIG. 5F have a first sensor group for measuring at least two magnetic field components, e.g. two or three orthogonal magnetic field components, e.g. two in-plane magnetic field components (Bxl, Byl); and have a second sensor group for measuring at least two magnetic field components, e.g. two or three orthogonal magnetic field components, e.g. an in-plane magnetic field component (Bx2 or By2) and an out-of-plane magnetic field component (Bz2).

[0283] FIG. 6 shows a sensor device 600 which can be seen as a variant of the sensor device 500 of FIG. 5A, wherein the first sensor group sg6a is configured for measuring two magnetic field gradients at the first sensor location gel, e.g. two out-of-plane gradients (dBz / dx and dBz / dy), along two orthogonal directions, e.g. as illustrated in FIG. 4A, and wherein the second sensor group sg6b is configured for measuring an in-plane component By2 oriented in the Y-direction and an out-of-plane component Bz2 oriented in the Z-direction at the second sensor location gc2. This sensor device 600 can be used in combination with a magnetic source 110 as illustrated in FIG. 1A, wherein the inner magnet portion 111 is preferably an axially magnetized dipole (e.g. as in FIG. IE), and the outer magnet portion 112 is preferably an axially magnetized ring magnet (e.g. as in FIG. 1G) or an AL magnetized ring magnet (e.g. as in FIG. 1H), but will also work if the inner magnet portion 111 is a diametrically magnetized dipole (e.g. as in FIG. ID).

[0284] The Hall elements Hl to H4 of FIG. 6 are located on a virtual circle, but that is not absolutely required, and the invention will also work if these Hall elements are located on a virtual ellipse. The distance dx between the Hall elements H3, H4 and the distance dy between the Hall elements Hl and H2 is preferably a value in the range from 600 pm to 1600 pm, or from 800 pm to 1200 pm, e.g. equal to about 1000 pm. It is important to note that the values of dx and dy do not need to be matched to the dimensions of the inner magnet portion 111. Indeed, the values of dx and dy may for example be chosen such that the ratio (dx / Dl) and (dyl / Dl) are values in the range from 25% to 150%, or in the range from 50% to 100%, or in the range from 50% to 90%.

[0285] It is noted that, using the sensor device 600, the first angle a can be determined in a manner which is highly insensitive to a magnetic disturbance field, but the second angle is sensitive to an external disturbance field.

[0286] As can be seen, the sensor device 600 has one disk-shaped IMC and six horizontal Hall elements. Everything else described above for the sensor device 500 of FIG. 5A is also applicable here, mutatis mutandis.

[0287] In a variant (not shown) of FIG. 6, the second sensor group sg6b is rotated by 90° about the Z- axis, and is capable of measuring a magnetic field component Bx2 oriented in the X-direction, and a magnet field component Bz2 oriented in the Z-direction. Such a sensor device may be better suited for use in combination with a magnetic source 110 comprising an inner magnet portion 111 that is diametrically magnetized (see e.g. FIG. ID) or preferably axially magnetized (see e.g. FIG. IE), and an outer magnet portion 112 in the form of a radially magnetized ring magnet (see FIG. IF).

[0288] In another or a further variant (not shown) of FIG. 6, the second sensor group sg6b is replaced by another 2D magnetic pixel, e.g. selected from FIG. 3B or FIG. 3C, optionally rotated by 90° rotated about the Z-axis.

[0289] In another or a further variant (not shown) of FIG. 6, the second sensor group sg6b is replaced by a 3D magnetic pixel, e.g. selected from FIG. 2A or FIG. 2C. The same advantages as were mentioned for the sensor device of FIG. 5E are also applicable here, e.g. that one of the three magnetic field components Bx2, By2, Bz2 is not absolutely required for calculating the second angle 0, but may be used for diagnostic purposes or for error detection, or can be used for automatic detection whether the ring magnet is axially or radially magnetized. FIG. 7A shows a sensor device 700 which can be seen as a variant of the sensor device 600 of FIG. 6, wherein the first sensor group is of the type shown in FIG. 4A, and wherein the second sensor group is of the type shown in FIG. 4B. The second sensor group sg7b is capable of measuring two magnetic field gradients, e.g. an in-plane gradient dBy / dy and an out-of-plane gradient dBz / dy along the Y-direction.

[0290] This sensor device 600 can be used in combination with a magnetic source 110 as illustrated in FIG. 1A, wherein the inner magnet portion 111 is a diametrically magnetized dipole (e.g. as in FIG. ID) but preferably is an axially magnetized dipole (e.g. as in FIG. IE), and wherein the outer magnet portion 112 is preferably an axially magnetized ring magnet (e.g. as in FIG. 1G).

[0291] It is a major advantage of this sensor device 700 that both the first angle a and the second angle P can be determined in a manner which is highly insensitive to an external disturbance field, hence also the overall angle 9 will be highly insensitive of an external disturbance field.

[0292] As can be seen, the sensor device 700 has two disk-shaped IMC's and eight horizontal Hall elements Hl to H8. Everything else described above for the sensor device 600 of FIG. 6A is also applicable here, mutatis mutandis.

[0293] It is noted that the distance dyl and dy2 can be chosen independently from each other. It is a further advantage that the value of dy2 does not need to be matched to the pole pitch of the ring magnet portion, but can be chosen substantially independent from the dimensions D2, D3 of the ring magnet, and also substantially independent from the number of pole pairs Npp.

[0294] In a variant (not shown) of the sensor device of FIG. 7A, the second sensor group is of the type shown in FIG. 4D, comprising two 2D pixels spaced apart in the Y-direction, wherein each 2D pixel comprises a Horizontal Hall element and two vertical Hall elements. This sensor device is functionally equivalent to the device shown in FIG. 7A. In a further variant, each 2D pixels comprises a horizontal Hall element and only one vertical Hall element (the other vertical Hall element being omitted).

[0295] FIG. 7B shows a sensor device 750 which can be seen as a variant of the sensor device of FIG. 7A, wherein the second sensor group sg7c is of the type shown in FIG. 4E, capable of measuring two magnetic field differences or gradients ABxy and ABzy along the Y-direction. The sensor device 750 may be better suited for use with a magnetic source 110 as illustrated in FIG. 1A having a ring magnet portion 112 which is diametrically magnetized (e.g. as shown in FIG. IF). The same advantages as the sensor device of FIG. 7A apply, including: highly insensitive to magnetic disturbance field, the values of dx and dyl do not need to be identical; the values of dyl and dy2 do not need to be identical; the values of dx, dyl can be chosen highly independent from the dimension DI of the inner magnet portion 111; the value of dy2 can be chosen highly independent from the dimensions D2, D3 of the outer magnet portion 112 and also highly independent from the number of pole pairs Npp. In a variant (not shown) of the sensor device of FIG. 7B, the second sensor group is of the type shown in FIG. 4F, comprising two 2D pixels spaced apart in the Y-direction, wherein each 2D pixel comprises a Horizontal Hall element and two vertical Hall elements. This sensor device is functionally equivalent to the device shown in FIG. 7B. In a further variant, each 2D pixels comprises a horizontal Hall element and only one vertical Hall element (the other vertical Hall element being omitted).

[0296] In yet another or a further variant (not shown) of FIG. 7A and FIG. 7B, the second sensor group is replaced by the sensor group sg4g of FIG. 4G or by the sensor group sg4h of FIG. 4H. This offers the additional advantage that the third magnetic field component, which is not required for calculating the second angle , can be used for diagnostic purposes, or for error detection, or for automatic determination whether the ring magnet is axially or radially magnetized.

[0297] FIG. 8 shows a sensor device 800 which can be seen as a variant of the sensor device 560 of FIG. 5C wherein the second sensor group is of the type shown in FIG. 4D and contains two 2D magnetic pixels spaced apart by a distance dy along the Y-axis.

[0298] This sensor device 800 can be used in combination with a magnetic source 110 as illustrated in FIG. 1A, wherein the inner magnet portion 111 is preferably a diametrically magnetized dipole (e.g. as in FIG. ID), and wherein the outer magnet portion 112 is preferably an axially magnetized ring magnet (e.g. as shown in FIG. 1G) or an AL magnetized ring magnet (e.g. as shown in FIG. 1H).

[0299] Even though only the second angle 0 is derived from magnetic field gradients, the overall angle 9 can still be determined in a manner which is highly insensitive to an external disturbance field, because only an approximate value of the first angle a or the first ratio R1 is required. It suffices that the signals provided by the first sensor group, or derived therefrom, are sufficiently accurate for determining the correct sector-count or sector-offset value, as explained above.

[0300] As is the case for all the sensor devices illustrated in FIG. 5A to FIG. 7, the absolute angular position 9 of the sensor device 800 can be determined inside or outside of the sensor device itself, based on the signals provided by the first sensor group sg8a and the signals provided by the second sensor group sg8b, or signals derived therefrom (e.g. R1 or a, and R2 or 0).

[0301] As can be seen, the sensor device 800 of FIG. 8 has three horizontal Hall elements and eight vertical Hall elements. Everything else described above for the sensor device 550 of FIG. 5C is also applicable here, mutatis mutandis.

[0302] In a variant (not shown) of the sensor device of FIG. 8, the horizontal Hall element Hl is omitted, and / or one of the vertical Hall elements V5, V6 is omitted, and / or one of the vertical Hall elements V7, V8 is omitted.

[0303] In another or further variant of the sensor device of FIG. 8, the second sensor group is of the type shown in FIG. 4F. This second sensor group is then capable of measuring a gradient ABxy=dBx / dy and ABzy=dBz / dy from which a second ratio R2 and / or a second angle can be derived. Such sensor device would preferably be used in combination with a magnetic source 110 as shown in FIG. 1A having an inner magnet portion 111 which is axially or preferably diametrically magnetized, and an outer magnet portion 112 which is preferably radially magnetized (e.g. as shown in FIG. IF).

[0304] Looking back to FIG. 5A to FIG. 8, it can be seen that:

[0305] - the sensor devices of FIG. 5A to FIG. 5F and their variants have a first sensor group for measuring at least two magnetic field components (more specifically two in-plane components); and have a second sensor group for measuring at least two magnetic field components (more specifically an in-plane component and an out-of-plane component);

[0306] - the sensor device of FIG. 6 and its variants have a first sensor group for measuring two magnetic field gradients (more specifically, two out-of-plane gradients); and have a second sensor group for measuring at least two magnetic field components (more specifically an in-plane component and an out-of-plane component along the Y-axis);

[0307] - the sensor device of FIG. 7A and FIG. 7B and their variants have a first sensor group for measuring two magnetic field gradients (more specifically, two out-of-plane gradients); and have a second sensor group for measuring two magnetic field gradients (more specifically, an in-plane gradient and an out-of-plane gradient along the Y-axis);

[0308] - the sensor device of FIG. 8 and its variants has a first sensor group for measuring at least two magnetic field components (more specifically two in-plane components); and have a second sensor group for measuring two magnetic field gradients (more specifically, an in-plane gradient and an out-of- plane gradient along the Y-axis), but other configurations are also possible.

[0309] In a further variant of the embodiments shown in FIG. 5A to FIG. 8, the first sensor group is replaced by the sensor group sg4c of FIG. 4C, or by a variant thereof having six horizontal Hall elements spaced apart by 60°. Such sensor device can be used for example in combination with a magnetic source as shown in FIG. 1A having an inner magnet portion 111 which is axially magnetized or diametrically magnetized. As mentioned above, the first angle a can be derived from the three (or six) measured values of Bz, or from pairwise difference values, optionally after subtraction of an average value, for example using a Clarke translation, and optionally an arctangent function.

[0310] FIG. 9 shows a sensor device 900 which can be seen as a variant of the sensor device 600 of FIG. 6, or as as a variant of the sensor device 700 of FIG. 7A, having a first sensor group sg9a comprising four horizontal Hall elements Hl to H4 arranged on a circle or on an ellipse for measuring two out-of- plane magnetic field gradients dBz / dx and dBz / dy; and having a second sensor group sg9b comprising three horizontal Hall elements H5, H6, H7 spaced apart by a distance dy9 along the Y-direction, configured for providing signals h5, h6, h7 indicative of the Bz-components at the respective locations. As can be seen, two magnetic field differences diffl and diff2 can be derived from these component signals, and a ratio R2 can be calculated of these differences, and a second angle can be calculated as a function of this ratio R2, inside or outside of the sensor device 900.

[0311] If the distance dy9 is equal to half of the pole pitch of the ring magnet 112, the signals h5, h6, h7 are substantially 90° phase shifted, and the second angle 0 can be calculated in accordance with the formula: 0=arctan(R2).

[0312] If the distance dy9 is not equal to half of the pole pitch of the ring magnet 112, the second angle 0 can be calculated using a so called "modified arctangent function", e.g. in accordance with the formula: 0=arctan(R2 / C±T), where C and T are predefined constants, which can be determined during a calibration procedure, or by simulation, and may be written in a non-volatile memory incorporated in the sensor device, or connected to the sensor device, or incorporated in an external processor (e.g. an ECU, see FIG. 13). Typically C*1 and T 0 in this case.

[0313] Instead of using mathematical formulas, it is also possible to calculate the second angle using a look-up table preferably with interpolation, for converting the ratio R2 into the second angle 0.

[0314] As can be seen, the sensor device 900 has seven horizontal Hall element, but does not comprise an integrated magnetic concentrator (IMC).

[0315] It is noted that the values of dx, dyl and dy2 may be identical, or dx and dyl may be identical but different from dy2, or may be three different values.

[0316] Since both the first angle a and the second angle 0 are derived from magnetic field differences or gradients, both the first and second angle a, 0 and thus also the overall angle 9 are highly insensitive to an external disturbance field.

[0317] This sensor device 900 can be used in combination with a magnetic source 110 as shown in FIG. 1A, having a diametrically or preferably axially magnetized dipole as the inner magnet portion 111, and having a radially or an axially or an AL magnetized ring magnet portion 112 (as illustrated in FIG. IF to FIG. 1H).

[0318] In a variant of FIG. 9, the Hall elements H5, H6, H7 are not located on a straight line, but are located on a virtual circle having a radius in the range from ds*80% to ds*120%, or in the range from ds*90% to ds*110%, or substantially equal to ds. The same formulas are applicable.

[0319] It is an important advantage of the sensor device of FIG. 9 that the first and second sensor group sg9a, sg9b only contain a single type of magnetic sensor elements, namely horizontal Hall elements, without IMC.

[0320] In another or a further variant of FIG. 9, the first sensor group sg9a comprising four horizontal Hall elements without IMC (e.g. as shown in FIG. 4A) is replaced by the sensor group sg4c of FIG. 4C having only three horizontal Hall elements spaced apart by multiples of 120°, or by a sensor group (not shown) having six horizontal Hall elements spaced apart by multiples of 60°, or by a 3D magnetic pixel (e.g. as illustrated in FIG. 2A or FIG. 2B or FIG. 2C) or by a 2D magnetic pixel capable of measuring two in-plane components, (e.g. as illustrated in FIG. 3D or FIG. 3E), and the first ratio R1 or the first angle a, or a sector count value, or a sector-offset-value can be determined based on signals provided by that first sensor group.

[0321] FIG. 10 shows a variant of FIG. 9, in which the first sensor group sglOa comprises only three horizontal Hall elements without an integrated magnetic concentrator (IMC). As can be seen, H2 is 90° spaced from Hl, and H3 is 180° spaced from Hl. A first difference signal diffl can be calculated between the signals hl and h2 obtained from Hl and H2 respectively. A second difference signal diff2 can be calculated between the signals h2 and h3 obtained from H2 and H3 respectively. These difference signals are substantially 90° phase shifted, and have substantially the same amplitude. A first ratio R1 and / or a first angle a can be derived from diffl and diff2.

[0322] The sensor device 1000 can be used in the angular sensor system of FIG. 1A, in combination with a magnetic source having an inner magnet portion 111 that may be diametrically magnetized or axially magnetized (e.g. as illustrated in FIG. ID or FIG. IE), and having an outer magnet portion 112 that can be radially or axially or AL magnetized (e.g. as illustrated in FIG. IF to FIG. 1H).

[0323] The main advantages of the sensor device 1000 over that of FIG. 9 is that it has only six horizontal Hall elements instead of seven, and can be implemented on a smaller die size. A disadvantage is that the accuracy of the first angle a may become more sensitive to mounting position offset, but this is not critical for the accuracy of the overall angle 9, especially if the signals from the first sensor group are only used to determine a sector counter, in which case the the value of R1 and a need not be very accurate, and thus the value of the overall angle 9 is tolerant to a moderate mounting position offset.

[0324] The resulting angle 9 is highly insensitive to an external disturbance field, since both the first angle a and the second angle [3 are derived from magnetic field differences or gradients. Everything else mentioned above for the sensor device of FIG. 9 is also applicable here.

[0325] In a variant (not shown) of FIG. 10, the Hall elements H4, H5, H6 are not located on a straight line, but are located on a virtual circle having a radius in the range from ds*80% to ds*120%, or in the range from ds*90% to ds*110%, or substantially equal to ds. The same formulas are applicable.

[0326] In a further variant of FIG. 9 and FIG. 10, the three horizontal Hall elements of the second sensor group are replaced by three vertical Hall elements oriented in the Y-direction (similar to the second sensor group of FIG. 11). Such sensor device is preferably used in combination with a magnetic source 111 having an outer ring magnet which is axially or AL magnetized (e.g. as illustrated in FIG. 1G or FIG. 1H).

[0327] In a further variant of FIG. 9 and FIG. 10, the three horizontal Hall elements of the second sensor group are replaced by three vertical Hall elements oriented in the X-direction. Such sensor device is preferably used in combination with a magnetic source 111 having an outer ring magnet which is radially magnetized (e.g. as illustrated in FIG. IF).

[0328] FIG. 11 shows another variant of FIG. 9, comprising a first sensor group sglla having four vertical Hall elements VI to V4 located on a virtual circle, two of them (VI, V2) having an axis of maximum sensitivity oriented in the X-direction, the other two (V3, V4) having an axis of maximum sensitivity oriented in the Y-direction; and having a second sensor group sgllb comprising three vertical Hall elements V5, V6, V7 oriented in the Y-direction, and spaced apart from each other by a distance dyll.

[0329] The sensor device 1100 of FIG. 11 is preferably used in combination with a magnetic source 110 as shown in FIG. 1A, comprising an axially magnetized or preferably a diametrically magnetized dipole magnet 111, and an axially or AL magnetized ring magnet portion 112 (e.g. as illustrated in FIG. 1G or FIG. 1H).

[0330] The second angle is derived from magnetic field differences or gradients, and is therefore highly insensitive to an external disturbance field. The first ratio Rl, and the first angle a are not derived from differences or gradients, and may therefore be sensitive to an external disturbance field, but since the signals from the first sensor group may only be used to determine a sector counter, the value of Rl and a need not be very accurate, and thus the value of the overall angle 0 is tolerant to a moderate disturbance field.

[0331] In a variant (not shown) of FIG. 10, the Hall elements H4, H5, H6 are not located on a straight line, but are located on a virtual circle having a radius in the range from ds*80% to ds*120%, or in the range from ds*90% to ds*110%, or substantially equal to ds. The same formulas are applicable.

[0332] In another or further variant of FIG. 11, the vertical Hall elements VI to V4 are not oriented in a radial direction (as illustrated in FIG. 11), but are oriented in a circumferential direction, and optionally also in this case two vertical Hall elements may be omitted.

[0333] In another or further variant (not shown), VI and V3 may be omitted, resulting in a sensor device having only five vertical Hall elements, and having a smaller die size. It is noted that the die size of the semiconductor substrate comprising at least the first sensor group sglla may be further reduced by positioning the vertical Hall elements V4 at the location A, and V2 at the location B. The same formulas are applicable, but the resulting first angle a would be 45° rotated. This offset can easily be taken into account when calculating the overall angle 0.

[0334] In another or further variant (not shown) of FIG. 11, the vertical Hall elements V5 to V7 of the second sensor group are 90° rotated about the Z-axis, such that their axes of maximum sensitivity are oriented in the X-direction. This sensor device is preferably used in combination with a magnetic source 110 as shown in FIG. 1A, comprising a ring magnet portion 112 that is radially magnetized. In the embodiments illustrated in FIG. 5A to FIG. 11, it is assumed that the geometric centre gel of the first sensor group is located "on-axis", i.e. substantially above the centre of the magnetic source (e.g. as illustrated in FIG. IB), and that the geometric centre gc2 of the second sensor group is located above the outer ring magnet portion 112 at a radial distance between R2 and R3, e.g. substantially halfway between the inner and outer diameter of the ring magnet, but this radial position is not critical.

[0335] In FIG. 14 to FIG. 16 an angular position sensor system will be described where the first sensor group is located "off-axis", but first illustrative block-diagrams of the sensor device are described in FIG. 12 and FIG. 13.

[0336] FIG. 12 shows a schematic block diagram of a sensor device 1200, as can be used in angular position sensor systems proposed by the present invention, e.g. in the angular position sensor system 120 of FIG. 1A or in the angular position sensor system 1420 of FIG. 14.

[0337] The sensor device 1200 comprises a first sensor group sgl2a comprising a plurality of sensor elements (e.g. SEI, SE2) allowing to determine at least two magnetic field components (e.g. Bx, By and optionally also Bz) or at least two magnetic field differences or gradients (e.g. dBz / dx, dBz / dy) at a first sensor location having a first geometric centre gel. The at at least two magnetic field components may be two in-plane components. The at least two magnetic field differences or gradients may be two out- of-plane gradients, optionally along two orthogonal directions. Examples of suitable first sensor groups are shown e.g. in FIG. 2A to FIG. 2C, FIG. 3D, FIG. 3E, FIG. 4A and FIG. 4C, or a variant of FIG. 4C having six horizontal Hall elements on a virtual circle spaced apart by multiples of 60°, or the first sensor group sglOa of FIG. 10 having only three horizontal Hall elements on a virtual circle spaced apart by 90°, or the first sensor group sglla of FIG. 11 having four vertical Hall elements on a virtual circle spaced apart by multiples of 90°, or a variant of the first sensor group sglla of FIG. 11 having only two vertical Hall elements on a virtual circle spaced apart by 90°.

[0338] The sensor device 1200 further comprises a second sensor group sgl2b comprising a plurality of sensor elements (e.g. SE3, SE4) allowing to determine at least two magnetic field components (e.g. By, Bz and optionally also Bx; or Bx, Bz and optionally also By) or at least two magnetic field differences or gradients (e.g. dBy / dy and dBz / dy; or dBx / dy and dBz / dy; or e.g. diffl, diff2 of FIG. 9 to FIG. 11) at a second sensor location having a second geometric centre gc2.

[0339] The first geometric centre gel and the second geometric centre gc2 are spaced apart by a predefined distance ds, e.g. in the range from 2.0 mm to 4.0 mm, or in the range from 2.5 mm to 4.0 mm, or in the range from 2.75 mm to 4.0 mm.

[0340] Examples of suitable second sensor groups sgl2b are shown e.g. in FIG. 2A to FIG. 3C, a variant of FIG. 3A to FIG. 3C rotated over 90° about the Z-axis, FIG. 4B, FIG. 4D to FIG. 4H, the second sensor group sg9b of FIG. 9, the second sensor group sglOb of FIG. 10 or the second sensor group sgllb of FIG. 11 or variants hereof wherein the vertical Hall elements are oriented in the X-direction.

[0341] The sensor device 1200 further comprises a biasing and readout circuit 1251 for biasing the magnetic sensor elements or sensor circuits containing the magnetic sensor elements (such as e.g. a Wheatstone bridge, not shown). Such circuits are well known in the art, and are not the main focus of the present invention, and hence do not need to be described in full detail. The biasing and readout circuit may comprise for example one or more current sources and / or voltage sources, one or more amplifiers, multiplexers, analog-to-digital convertors (ADC), etc.

[0342] The sensor device 1200 typically also comprises at least one temperature sensor (not explicitly shown) for measuring a temperature of the magnetic sensor elements, and for correcting a sensitivity of the magnetic sensor element. It is noted that a single (first) temperature sensor may be sufficient to measure the temperature of the sensor elements of the first sensor group, especially if these sensor elements are situated at a distance of at most 400 nm distance from the temperature sensor. Since the second sensor location gc2 is located relatively far away from the first sensor location, preferably at least a second temperature sensor (not explicitly shown) is located in the vicinity of the second sensor group, especially if the first and second sensor group are implemented on two separate semiconductor substrates. Optionally the second sensor group may comprise two temperature sensors, e.g. one temperature sensor for each sensor subgroup (e.g. in case any of the sensor groups of FIG. 4B, FIG. 4D to FIG. 4H is used), especially if the two subgroups are spaced apart by more than 400 pm.

[0343] The sensor device 1200 further comprises an output circuit 1253 for outputting one or more of: the measured signals si, s2, etc; the amplified and digitized signals SI, S2, etc.; difference values diffl, diff2, etc.; the first ratio Rl, the second ratio R2, the first angle a, a sector-count, a sector-offset (related to the sector-count), the second angle [3, the overall angle 9.

[0344] The sensor device 1200 may further comprise a processing circuit 1252, e.g. a digital processing circuit, e.g. comprising a CPU or a Digital Signal Processor (DSP), e.g. configured for calculating one or more of said differences, said first ratio Rl, second ratio R2, first angle a, second angle [3, and overall angle 9.

[0345] The sensor device 1200 may further comprise a non-volatile memory 1254, e.g. flash, which may be incorporated in the processing circuit, or may be connected to the processing circuit, and which may store one or more parameters, for example selected from the following list:

[0346] - the number Npp of pole pairs;

[0347] - a parameter indicating whether the ring magnet portion is axially or radially or AL magnetized, which parameter may e.g. be used for example to determine which magnetic field components or gradients are to be used to calculate the second ratio R2 or the second angle [3 (see e.g. FIG. 7A and FIG. 7B);

[0348] - parameters C and T as explained in FIG. 9 to FIG. 11; - a look-up table for implementing the arctangent function;

[0349] - one or more values of magnetic field strength;

[0350] - one or more threshold values (e.g. a minimum and a maximum value ) related to the magnetic field strength of the envisioned inner magnet portion that is to be measured by the first sensor group;

[0351] - one or more values (e.g. a minimum and a maximum value ) related to the magnetic field strength of the envisioned outer magnet portion that is to be measured by the second sensor group;

[0352] - etc.

[0353] In preferred embodiments, the non-volatile memory also stores an angular offset value related to an angular offset between the inner magnet portion 111 and the outer magnet portion 112, which value is to be taken into account by the algorithm that determines the overall angle 9. Such a device can be used in combination with a magnetic source 110, 1410 in which the inner magnet portion and the outer magnet portion are not angularly aligned, but have a random or pseudo-random angular position relative to each other. This offset can be measured during a calibration procedure (e.g. at system-level or sub-assembly-level), and can then be stored in said non-volatile memory for use during normal operation.

[0354] In an embodiment, the overall angular position 9 is calculated inside the sensor device 1200, but the present invention is not limited hereto, and it is also possible that the angular position 9 is calculated outside of the sensor device (e.g. will be described and illustrated in FIG. 13).

[0355] In an embodiment, the first sensor group may be a 2D magnetic pixel, capable of measuring two in-plane components at the first sensor location gel, but not an out-of-plane component.

[0356] In an embodiment, the first sensor group may be a 3D magnetic pixel, capable of measuring three orthogonal components at the first sensor location gel.

[0357] In an embodiment, the first sensor group may comprise a plurality of two to six (e.g. only 2, or only 3, or only 4, or only 6) magnetic sensor elements, e.g. horizontal Hall elements or vertical Hall elements arranged on an imaginary circle having the first sensor location gel as its centre. This imaginary circle preferably has a diameter in the range from 600 pm to 1600 pm, or from 800 pm to 1200 pm, e.g. equal to about 1000 pm.

[0358] Importantly, the sensor device 1200 is a single packaged semiconductor device, typically referred to as "chip package". The sensor device 1200 may comprise a single semiconductor substrate, or more than one semiconductor substrate, e.g. a first semiconductor substrate comprising the first sensor group, and a second semiconductor substrate comprising the second sensor group. These semiconductor substrates may be mounted on a lead frame, and interconnected via bond wires, or may be interconnected by means of one or more RDL layers in a single WLP-package (Wafer Level Packaging).

[0359] Optionally, the sensor device 1200 may be further configured for determining a diagnostic signal, e.g. by calculating a sum of squares of two or three magnetic field components or magnetic field gradients measured at the first or second sensor location, and by testing if this sum falls between predefined threshold values (e.g. between a minimum value and a maximum value which are stored in the NV-memory). In some embodiments, an error is generated in case the first angle a and the second angle are inconsistent, optionally taking into account the number of pole pairs Npp, and / or the above described angular offset-value between the inner magnet portion and outer magnet portion which was stored in the NV-memory during a calibration step.

[0360] In a variant (not shown), the sensor device 1200 further comprises a third sensor group, connected to the biasing and readout circuit 1251, and the biasing and readout circuit 1251 would be further configured for also biasing the sensor of the third sensor group and for obtaining signals provided by the third sensor group; and the processing circuit 1252 (if available) may be further configured for processing also the signals obtained from the third sensor group; and the output circuit 1253 may be configured for outputting signals provided by the third sensor group. Such a sensor device may be used for example in an angular position sensor system of FIG. 22 or FIG. 24.

[0361] FIG. 13 shows a schematic block diagram of another sensor device 1300 which can be used in angular position sensor systems proposed by the present invention, e.g. in the angular position sensor system 120 of FIG. 1A or in the angular position sensor system 1420 of FIG. 14.

[0362] The sensor device 1300 of FIG. 13 can be seen as a variant of the sensor device 1200 of FIG. 12. The main difference being that the sensor device 1300 comprises at least two semiconductor substrates, including: a first semiconductor substrate 1303a comprising the first sensor group sgl3a, and a second semiconductor substrate 1303b comprising the second sensor group sgl3b; and that the angular position 9 is calculated outside of the sensor device 1300, e.g. in an external processor 1399, e.g. an ECU (Electronic Control Unit).

[0363] In the example shown in FIG. 13, each semiconductor substrate 1303a, 1303b has a sensor group sgl3a, sgl3b, a biasing and readout circuit 1351a, 1351b, an output circuit 1353a, 1353b, and optionally also a processing circuit 1352a, 1352b. As mentioned above, the biasing and readout circuits typically comprise at least one amplifier and ADC for amplifying and digitizing the measured signals, yielding digital signals SI, S2, S3, S4.

[0364] If the processing circuit 1352a is absent, the output circuit 1353a can output at least the amplified and digitized signals SI, S2. If the processing circuit 1352a is present, it may be configured to determine one or more of the following values derived from the signals provided by the first sensor group: first ratio Rl, first angle a, a sector-count, angular offset corresponding to that sector-count). In this case, the output circuit 1353a may output one or more of these derived signals, instead of, or in addition to the digital signals SI, S2. The first semiconductor substrate may also output a first error signal errorl, for example for indicating that the magnetic field strength detected by the first sensor group is too weak. Likewise, if the processing circuit 1352b is absent, the output circuit 1353b can output at least the amplified and digitized signals S3, S4. If the processing circuit 1352b is present, it may be configured to determine one or more of the following values derived from the signals provided by the second sensor group: second ratio R2, second angle [3, angle / Npp). In this case, the output circuit 1353b may output one or more of these derived signals, instead of, or in addition to the signals S3, S4. The second semiconductor substrate may also output a second error signal error2, for example for indicating that the magnetic field strength detected by the second sensor group is too weak.

[0365] Many variants of this sensor device 1300 are possible, for example, the sensor device 1300 may still comprise two semiconductor substrates, and one of the semiconductor substrates comprises a processing circuit, but the other semiconductor substrate does not comprise a processing circuit.

[0366] It is also possible that one of the semiconductor substrates provides its output signals to the other semiconductor substrates, and that the sensor device 1300 only has a single output port.

[0367] In embodiments of the present invention, the sensor device 1300 is a single packaged device having two sensor groups, which are spaced apart by the distance ds, which may be a value in the range from 1.0 to 4.0 mm, or in the range from 1.5 to 3.5 mm, or in the range from 2.0 to 3.5 mm.

[0368] While not explicitly shown, one or both of the semiconductor substrates 1303a, 1303b may comprise a non-volatile memory (e.g. flash).

[0369] In a variant (not shown), the sensor device 1300 further comprises a third semiconductor substrate similarto or identical to the second semiconductor substrate 1303b. Such a sensor device may be used for example in an angular position sensor system of FIG. 22 or FIG. 24.

[0370] FIG. 14 shows another angular position sensor system 1420 proposed by the present invention, which can be seen as a variant of the angular position sensor system 120 shown in FIG. 1A. The sensor system 1420 of FIG. 14 comprises: a magnetic source 1410 and a single packaged sensor device 1400 mounted relative to the magnetic source 1410.

[0371] The magnetic source 1410 of FIG. 14 is similar or identical to that of FIG. 1A and comprises: an inner magnet portion in the form of a magnetic dipole 1411 (e.g. diametrically or axially magnetized), and an outer magnet portion 1412 in the form of a multipole ring magnet 1412 (e.g. axially or radially or AL magnetized), having at least three or at least four or at least five or at least six pole pairs (Npp).

[0372] The sensor device 1400 of FIG. 14 is a single packaged semiconductor device (also known as "chip"), and like the sensor device 100 of FIG. 1A, the sensor device 1400 also comprises a first sensor group 1401 for measuring signals generated by the inner magnet portion 1411, and a second sensor group 1402 for measuring signals generated by the outer magnet portion 1412, but in contrast to the sensor device of FIG. 1A, the geometric centre gel of the first sensor group is not located on the rotation axis of the magnet. This offers the advantage that the distance "ds" between the geometric centre gel of the first sensor group 1401 and the geometric centre gc2 of the second sensor group 1402 may be smaller than the distance "dec" between the centre of the inner magnet portion 1411 and the centre track 1414 of the ring magnet 1412. This also allows the size of the packaged device to be reduced. This is particularly interesting if the packaged device comprises a single semiconductor substrate, because a decreased distance "ds" also means a reduced size of the single semiconductor die, and thus a higher degree of miniaturization and a reduced cost.

[0373] It was found that the signals provided by the first sensor group of such device may experience somewhat more cross-talk from the ring magnet portion. It was also found that the amount of cross-talk may be reduced by increasing the diameter of the inner magnet portion.

[0374] In FIG. 14, the geometric centre gc2 of the second sensor group 1402 is located at a radius x2 between R2 and R3 from the rotation axis at the centre of the magnetic source 1410, and gc2 may be located on the centreline 1414 of the ring magnet portion, but that is not absolutely required, and other positions between R2 and R3 are also possible.

[0375] In preferred embodiments of FIG. 14, ds < (R2+R3) / 2, wherein D2 is the inner diameter of the ring magnet 1412, and D3 is the outer diameter of the ring magnet 1412.

[0376] In an embodiment with Rl=1.0 mm, the value of xl may be a value in the range from 0.3 mm to 0.9 mm, or in the range from 0.5 mm to 0.9 mm. In general, for a given ring magnet with inner radius R2 and outer radius R3, the ratio of (R1 / R2) may be a value in the range from 50% to 100%, and the ratio of (xl / Rl) may be a value in the range from 30% to 90%, or from 50% to 75%. As mentioned above, the radius R1 may be substantially equal to or only marginally smaller than the radius R2, or in practice (R1 / R2) may be a value in the range from 90% to 99%.

[0377] FIG. 15 shows a first variant of the sensor device 1400 of FIG. 14, wherein each of the first sensor group sgl5a and the second sensor group sgl5b is configured for measuring two magnetic field components. In this case, the first sensor group 1401 may comprise a 2D magnetic pixel capable of measuring at least two magnetic field components, more specifically, an in-plane component By and an out-of-plane component Bz, e.g. as illustrated in FIG. 15, but other 2D magnetic pixels for measuring By and Bz may also be used, e.g. the 2D magnetic pixel of FIG. 3B or FIG. 3C. Alternatively the first sensor group 1401 may comprise a 3D magnetic pixel, e.g. any of the 3D magnetic pixels shown in FIG. 2A to FIG. 2C.

[0378] In the embodiment of FIG. 15, the second sensor group sgl5b is also the 2D magnetic pixel of FIG. 3A, configured for measuring By2, Bz2 at the second sensor location, but other sensor groups can also be used, for example any of the second groups of the sensor devices shown in FIG. 5A to FIG. 11, or the variants described therein.

[0379] FIG. 16 shows a second variant of the sensor device 1400 of FIG. 14, wherein the first sensor group sgl6a is configured for measuring two magnetic field components Byl, Bzl, (the same components as the sensor device 1500 of FIG. 15), but wherein the second sensor group sgl6b is configured for measuring two magnetic field gradients.

[0380] In the example shown in FIG. 16, which may preferably be used in combination with a magnetic source comprising an axially magnetized ring magnet, the gradients dBz / dy and dBy / dy are determined.

[0381] In the example shown in FIG. 16, the first sensor group comprises the 2D magnetic pixel sg3a of FIG. 3A, but other 2D magnetic pixels may also be used, e.g. the 2D magnetic pixel of FIG. 3B or FIG. 3C. Alternatively the first sensor group may comprise a 3D magnetic pixel, e.g. any of the 3D magnetic pixels shown in FIG. 2A to FIG. 2C.

[0382] In the example shown in FIG. 16, the second sensor group sgl6b comprises the sensor group sg4b of FIG. 4B, which is capable of measuring two magnetic field gradients, one gradient of an in-plane component (e.g. By) and one gradient of an out-of-plane component (e.g. Bz), but other sensor groups capable of measuring an in-plane gradient (e.g. dBx / dy or dBy / dy) and an out-of-plane gradient (e.g. dBz / dy) may also be used, e.g. the sensor group sg4d of FIG. 4D also capable of determining dBy / dy and dBz / dy which is preferably used in combination with a magnetic source 1410 comprising a ring magnet that is axially magnetized; or the sensor group sg4e of FIG. 4E or the sensor group sg4f of FIG. 4F which are both capable of determining dBx / dy and dBz / dy, which are preferably used in combination with a magnetic source 1410 comprising a ring magnet that is radially magnetized. In yet another variant, the second sensor group comprises a sensor group as shown in FIG. 4G or FIG. 4H comprising two 3D pixels spaced apart in the Y-direction. Such a sensor device can e.g. be used with a magnetic source comprising an outer magnet portion which is radially or axially or AL magnetized. The sensor device may be configured for automatically detecting the magnetization direction of the ring magnet, and select the corresponding set of formulas, for example in the manner explained above. While only two gradients are required for determining the second angle [3, the third gradient may also be used for diagnostic purposes, e.g. to test if the distance "g" between the magnetic course and the ring magnet lies without predefined boundaries, for example by determining a sum of squares of gradients and comparing this sum with one or two threshold values.

[0383] It is a major advantage of the embodiments represented by FIG. 16, that the distance dy of the second sensor group is independent of the pole pitch of the ring magnet, and can thus be used in combination with magnetic sources having a ring magnet having various numbers of pole pairs Npp.

[0384] FIG. 17A shows a simulation model for the magnetic source 110, 1410 shown in FIG. 1A and in FIG. 14. In the specific example shown, the inner magnet portion 1711a has a diameter of 2.0 mm, and the ring magnet portion 1712a has an inner diameter of 4.0 mm and an outer diameter of 8.0 mm, but the present invention is not limited hereto. The magnetic source may have a height (or thickness) in axial direction in the range from 0.5 mm to 3.0 mm, or in the range from 0.5 to 2.5 mm, or in the range from 0.75 mm to 2.0 mm, or in the range from 0.75 mm to 1.5 mm, e.g. equal to about 0.8 mm, or equal to about 0.9 mm, or equal to about 1.0 mm, or equal to about 1.1 mm, or equal to about 1.2 mm. Simulations were performed using a software-tool commercially available under the name COMSOL.

[0385] FIG. 17A shows a magnetic source 1710a having an inner and an outer magnet portion that are magnetized using a block-wise magnetization. FIG. 17B shows a magnetic source 1710b having an inner and an outer magnet portion that are magnetized using a sinusoidal magnetization. The same formulas mentioned above are applicable in both cases, and in both cases a linearization function (e.g. using a piecewise linear approximation) may be used to slightly adapt / correct the value of the second angle .

[0386] FIG. 17A and FIG. 17B show grayscale pictures. FIG. 17C and FIG. 17D also show grayscale pictures but using a different color conversion to better illustrate the location of the north and south poles. FIG. 17E and FIG. 17F show dithered pictures. FIG. 17C to FIG. 17F are provided for illustrative purposes only.

[0387] In variants (not shown), the inner magnet portion may be axially magnetized, and / or the ring magnet portion may be tangentially magnetized or radially magnetized.

[0388] FIG. 18 and FIG. 19 shows a simulation result for the three orthogonal magnetic field components Bx, By, Bz of the combined magnetic fields generated by the magnetic source 1710 shown in FIG. 17B having an inner magnet portion 1711b in the form of a diametrically magnetized dipole, and an outer magnet portion 1712b in the form of an axially magnetized ring magnet.

[0389] FIG. 18 shows the simulation results at 0.5 mm distance above the centre of the inner magnet portion (i.e. at radial position r=0.0 mm) as a function of the rotation angle 9, as can be measured by the first sensor group 101 of the sensor device 100 of FIG. 1A. As can be seen, (i) the amplitudes of the magnetic field components are surprisingly high (e.g. almost 40 mT) for such a small magnet (DI is only 2.0 mm), and (ii) there is surprisingly almost no cross-talk from the outer magnet portion to the first sensor location, which was very surprising, and may be related to the fact that the inner magnet portion and the outer magnet portion are magnetized in perpendicular directions.

[0390] FIG. 19 shows the simulation results at 0.5 mm distance above the centreline 1714b of the outer magnet portion 1712b (i.e. at radial position r=3.0 mm) as a function of the rotation angle 9, as can be measured by the second sensor group 102 of the sensor device 100 of FIG. 1A. As can be seen, (i) the amplitudes of two of the magnetic field components are surprisingly high (e.g. almost 40 mT) for such a narrow ring magnet (the track width tw is only 2.0 mm), (ii) the signals By and Bz are almost perfect quadrature signals, (iii) the signal Bx not only has a very small value (only about 7 mT), and (iv) surprisingly has only a minimal distortion (ripple) at the frequency or periodicity of the inner magnet portion. This simulation show that there is also almost no cross-talk from the inner magnet portion to the second sensor location above the ring magnet, which again was very surprising, and may be related to the fact that the inner magnet portion and the outer magnet portion are magnetized in perpendicular directions. FIG. 20 shows a simulation similarto that of FIG. 18, but at a distance of 1.0 mm above the inner magnet portion 1711b, and FIG. 21 shows a simulation similar to that of FIG. 19, but at a distance of 1.0 mm above the centreline 1714b of the ring magnet portion 1712b. As can be seen, if the sensor device is positioned further away from the magnetic source, the signal levels drop dramatically to about 12 mT in FIG. 20 and to about 10 mT in FIG. 21, but the cross-talk caused by the outer magnet portion measured above the inner magnet portion (FIG. 20) and the cross-talk caused by the inner magnet portion measured above the ring magnet portion remain surprisingly low.

[0391] It shall be clear that the signal levels and amount of cross-talk may slightly differ for other magnetic sources and sensor positions.

[0392] FIG. 22A to FIG. 22C show an illustrative example of another angular position sensor system 2220, proposed by the present invention, comprising a first sensor group above the inner magnet portion, and a second and a third sensor group above the ring magnet, angularly spaced apart by 180°. The angular position sensor system of FIG. 22 can be seen as a variant of the angular position sensor system of FIG. 1, the main differences being: i) that the sensor system of FIG. 22A not only comprises a first sensor group 2201 having a first geometric centre gel located above the inner magnet portion 2211, and a second sensor group 2202 having a second geometric centre gc2 located above the outer magnet portion 2212, but further comprises a third sensor group 2203 having a third geometric centre gc3, also located above the outer magnet portion, but diametrically opposite the second geometric centre gc2; ii) that the overall angular position will be calculated in a different manner. This will be explained further in FIG. 23, which will explain further, by means of an example, how the signals from the three sensor groups can be combined to provide an overall angle.

[0393] Everything else described above, e.g. regarding the dimensions and magnetization of the magnet assembly, is also applicable here, mutatis mutandis. For example, as mentioned above, the inner magnet portion may e.g. be diametrically magnetized or axially magnetized, and the outer magnet portion may be axially magnetized, radially magnetized or AL (axial-lateral or arc shaped) magnetized. All six combinations are contemplated, but the present invention is not limited hereto, and other suitable types of magnetization for the inner magnet portion and the outer magnet portion may also be used.

[0394] The third sensor group 2203 may have the same structure as the second sensor group (e.g. using one of the sensor structures shown in FIG. 5A to FIG. 11), but that is not absolutely required, and in some embodiments, the second and the third sensor group are implemented using different sensor structures.

[0395] The sensor device 2200 may comprise three semiconductor dies, each semiconductor die comprising one of the first, second and third sensor groups, and optionally also further circuitry, e.g. similar as described in FIG. 13. These semiconductor dies may be mounted on a substrate, or assembled in another suitable manner.

[0396] The sensor device 2200 of FIG. 22 may be implemented as a single packaged semiconductor device (known as a "chip"), e.g. as a WLP (wafer level packaged) device, but that is not absolutely required, and the sensor device 2200 can also be implemented as a substrate (e.g. a printed circuit board) comprising said semiconductor dies.

[0397] FIG. 22B shows a cross-section of the sensor system 2220 of FIG. 22A in a plane A-A, in case the inner magnet portion 2211 is a diametrically magnetized dipole having a cylindrical shape, and in case the outer magnet portion 2212 is an axially magnetized ring magnet having a single track and (2N+1) pole pairs, N being an integer, and / or if the number of magnetic poles of the ring magnet visible to the sensor device 2200 is (4N+2), e.g. 6, 10, 14, etc.

[0398] FIG. 22B is a variant of FIG. IB, wherein the sensor device 2200 has three sensor groups instead of only two. Everything else described above for FIG. IB is also applicable here, mutatis mutandis.

[0399] FIG. 22C shows a cross-section of the sensor system 2220 of FIG. 22A in a plane A-A, in case the inner magnet portion 2211 is a diametrically magnetized dipole having a cylindrical shape, and in case the outer magnet portion 2212 is an axially magnetized ring magnet having a single track and (2N) pole pairs, N being an integer, and / or if the number of magnetic poles of the ring magnet visible to the sensor device 2200 is (4N), e.g. 8, 12, 16, 20 etc.

[0400] FIG. 22C is a variant of FIG. 1C, wherein the sensor device 2200 has three sensor groups instead of only two. Everything else described above for FIG. 1C is also applicable here, mutatis mutandis.

[0401] FIG. 23 shows an illustrative example of a sensor device 2200 that can be used in the angular position sensor system of FIG. 22. In the example shown, the first and sensor group sgl, sg2 are those of FIG. 6, and the third sensor group sg3 uses the same structure as the second sensor group.

[0402] But the present invention is not limited to this particular combination, and in variants of FIG. 23, the first and the second sensor group can be any of the combinations shown in FIG. 5A to FIG. 11, with the addition of a third sensor group having the same structure as the second sensor group, but shifted and optionally rotated over 180°.

[0403] The absolute angular position can be determined in different ways, for example: i) In a first manner, the absolute angular position (e.g. 91) is determined by: a) determining a coarse signal (e.g. a) based on the signals obtained from the first sensor group sgl (e.g. as described in FIG. 5A to FIG. 11); b) determining a first fine signal (e.g. (32) based on the signals obtained from the second sensor group sg2 (e.g. as described in FIG. 5A to FIG. 11); c) determining a second fine signal (e.g. (33) based on the signals obtained from the third sensor group sg3 (e.g. as described in FIG. 5A to FIG. 11); d) determining the absolute angular position (e.g. 91) based on the coarse signal (e.g. a) and based on an average (e.g. avg) of the first and second fine signal (e.g. ( 2, (33).

[0404] This first technique may be particularly useful in combination with a magnet assembly having 4N or (4N+2) magnetic poles facing the sensor device, N being an integer, in which case (ideally) the magnetic field sensed by the second and third sensor group are equal, or opposite (in the absence of a magnetic disturbance field). The absolute angular position 91 thus determined may have an improved signal-to-noise ratio (SNR), a reduced sensitivity to mounting offset, eccentricity, magnet imperfections, manufacturing tolerances of the sensor device and / or the magnet assembly, vibrations, or combinations hereof. ii) In a second manner, the absolute angular position (e.g. 92) is determined by: a) determining a coarse signal (e.g. a) based on the signals obtained from the first sensor group sgl (e.g. as described in FIG. 5A to FIG. 11); b) determining a fine signal (e.g. sum) based on a first and a second sum (e.g. suml, sum2) of magnetic field components obtained from the second and third sensor group sg2, sg3 (e.g. as described in FIG. 5A to FIG. 11); c) determining the absolute angular position (e.g. 92) based on the coarse signal (e.g. a) and based on the fine signal (e.g. sum).

[0405] This second technique may be particularly useful in combination with a magnet assembly having 4N magnetic poles facing the sensor device, N being an integer, in which case (ideally) the magnetic field components sensed by the second and third sensor group are equal (in the absence of a magnetic disturbance field). The absolute angular position 92 thus determined may have an improved signal-to-noise ratio (SNR), a reduced sensitivity to mounting offset, eccentricity, magnet imperfections, manufacturing tolerances of the sensor device and / or the magnet assembly, vibrations, or combinations hereof. iii) In a third manner, the absolute angular position (e.g. 93) is determined by: a) determining a coarse signal (e.g. a) based on the signals obtained from the first sensor group (e.g. as described in FIG. 5A to FIG. 11); b) determining a fine signal (e.g. (Bdiff) based on a first and a second difference (e.g. diffl, diff2) of magnetic field components obtained from the second and third sensor group (e.g. as described in FIG. 5A to FIG. 11); c) determining the absolute angular position (e.g. 93) based on the coarse signal (e.g. a) and based on the fine signal (e.g. (Bdiff).

[0406] This third technique may be particularly useful in combination with a magnet assembly having (4N+2) magnetic poles facing the sensor device, N being an integer, in which case (ideally) the magnetic field components sensed by the second and third sensor group have opposite sign (in the absence of a magnetic disturbance field). The absolute angular position 93 thus determined may have an improved signal-to-noise ratio (SNR), a reduced sensitivity to mounting offset, eccentricity, magnet imperfections, manufacturing tolerances of the sensor device and / or the magnet assembly, vibrations, or combinations hereof, and will also have a reduced sensitivity to an external disturbance field. FIG. 24A to FIG. 24C show an illustrative example of another angular position sensor system 2420, proposed by the present invention, comprising a first sensor group 2401 above the inner magnet portion, and a second and a third sensor group 2402, 2403 above the ring magnet, angularly spaced apart by 90°. The angular position sensor system of FIG. 24 can be seen as a variant of the angular position sensor system of FIG. 22, the main differences being: i) that the third sensor group is not located diametrically opposite the second sensor group, but a first virtual line segment from the first to the second geometric centre gel, gc2, and a second virtual line segment from the first to the third geometric centre gel, gc3 form an angle of 90°; ii) that the overall angular position will be calculated in a different manner, explained further in FIG. 25;

[0407] The third sensor group 2403 may have the same structure as the second sensor group 2402 (e.g. using one of the sensor structures shown in FIG. 5A to FIG. 11), but that is not absolutely required, and in some embodiments, the second and the third sensor group are implemented using different sensor structures.

[0408] The sensor device 2200 may comprise three semiconductor dies, each semiconductor die comprising one of the first, second and third sensor groups, and optionally also further circuitry, e.g. similar as described in FIG. 13. These semiconductor dies may be mounted on a substrate, or assembled in another suitable manner.

[0409] The sensor device 2400 of FIG. 24 may be implemented as a single packaged semiconductor device (known as a "chip"), e.g. as a WLP (wafer level packaged) device, but that is not absolutely required, and the sensor device 2400 can also be implemented as a substrate (e.g. a printed circuit board) comprising said semiconductor dies.

[0410] FIG. 24B shows a cross-section of the sensor system 2420 of FIG. 24A in a plane parallel to the Z-axis, along the broken line [C-B] and [C-A], in case the inner magnet portion 2411 is a diametrically magnetized dipole having a cylindrical shape, and in case the outer magnet portion 2412 is an axially magnetized ring magnet having a single track with (4N+2) pole pairs, or (8N+4) magnetic poles facing the sensor device, N being an integer number. The second and third sensor group sg2, sg3 will sense magnetic fields originating from the magnet assembly 2410 oriented in opposite directions.

[0411] FIG. 24C shows a cross-section of the sensor system 2420 of FIG. 24A in a plane parallel to the Z-axis, along the broken line [C-B] and [C-A], in case the inner magnet portion 2411 is a diametrically magnetized dipole having a cylindrical shape, and in case the outer magnet portion 2412 is an axially magnetized ring magnet having a single track with (4N) pole pairs, or (8N) magnetic poles facing the sensor device, N being an integer number. The second and third sensor group sg2, sg3 will sense magnetic fields originating from the magnet assembly 2410 oriented in the same direction. It is pointed out, however, that the inner magnet portion and the outer magnet portion may be magnetized in another suitable manner.

[0412] FIG. 25 shows an illustrative example of a sensor device 2400 that can be used in the angular position sensor system of FIG. 24. In the example shown, the first and sensor group sgl, sg2 are those of FIG. 6, and the third sensor group sg3 uses the same structure as the second sensor group, but is shifted and rotated over 90°. But the present invention is not limited to this particular combination, and in variants of FIG. 23, the first and the second sensor group can be any of the combinations shown in FIG. 5A to FIG. 11, with the addition of a third sensor group having the same structure as the second sensor group, but shifted and rotated over 90°. The sensor device 2400 may have an overall square shape.

[0413] The absolute angular position can be determined in different ways, for example: i) In a first manner, the absolute angular position (e.g. 91) is determined by: a) determining a coarse signal (e.g. a) based on the signals obtained from the first sensor group sgl (e.g. as described in FIG. 5A to FIG. 11); b) determining a first fine signal (e.g. (32) based on the signals obtained from the second sensor group sg2 (e.g. as described in FIG. 5A to FIG. 11); c) determining a second fine signal (e.g. (33) based on the signals obtained from the third sensor group sg3 (e.g. similar to those described in FIG. 5A to FIG. 11, but taking into account a 90° rotation); d) determining the absolute angular position (e.g. 91) based on the coarse signal (e.g. a) and based on an average (e.g. |3avg) of the first and second fine signal (e.g. [32, (33).

[0414] This first technique may be particularly useful in combination with a magnet assembly having 8N or (8N+4) magnetic poles facing the sensor device, N being an integer, in which case (ideally) the magnetic field sensed by the second and third sensor group are equal, or opposite (in the absence of a magnetic disturbance field). The absolute angular position 91 thus determined may have an improved signal-to-noise ratio (SNR), a reduced sensitivity to mounting offset, eccentricity, magnet imperfections, manufacturing tolerances of the sensor device and / or the magnet assembly, vibrations, or combinations hereof. ii) In a second manner, the absolute angular position (e.g. 92) is determined by: a) determining a coarse signal (e.g. a) based on the signals obtained from the first sensor group sgl (e.g. as described in FIG. 5A to FIG. 11); b) determining a fine signal (e.g. |3sum) based on a first and a second sum (e.g. suml, sum2) of magnetic field components obtained from the second and third sensor group sg2, sg3 (e.g. similar to those described in FIG. 5A to FIG. 11, taking into account a 90° rotation for the third sensor group); c) determining the absolute angular position (e.g. 93) based on the coarse signal (e.g. a) and based on the fine signal (e.g. |3sum).

[0415] This second technique may be particularly useful in combination with a magnet assembly having 8N magnetic poles facing the sensor device, N being an integer, in which case (ideally) the magnetic field components sensed by the second and third sensor group are equal (in the absence of a magnetic disturbance field). The absolute angular position 92 thus determined may have an improved signal-to-noise ratio (SNR), a reduced sensitivity to mounting offset, eccentricity, magnet imperfections, manufacturing tolerances of the sensor device and / or the magnet assembly, vibrations, or combinations hereof. iii) In a third manner, the absolute angular position (e.g. 93) is determined by: a) determining a coarse signal (e.g. a) based on the signals obtained from the first sensor group (e.g. as described in FIG. 5A to FIG. 11); b) determining a fine signal (e.g. (Bdiff) based on a first and a second difference (e.g. diffl, diff2) of magnetic field components obtained from the second and third sensor group (e.g. similar to those described in FIG. 5A to FIG. 11, taking into account a 90° rotation for the third sensor group); c) determining the absolute angular position (e.g. 93) based on the coarse signal (e.g. a) and based on the fine signal (e.g. (Bdiff).

[0416] This third technique may be particularly useful in combination with a magnet assembly having (8N+4) magnetic poles facing the sensor device, N being an integer, in which case (ideally) the magnetic field components sensed by the second and third sensor group have opposite sign (in the absence of a magnetic disturbance field). The absolute angular position 93 thus determined may have an improved signal-to-noise ratio (SNR), a reduced sensitivity to mounting offset, eccentricity, magnet imperfections, manufacturing tolerances of the sensor device and / or the magnet assembly, vibrations, or combinations hereof.

[0417] REFERENCES:

[0418] (References modulo 100)

[0419] -00 sensor device (single packaged device)

[0420] -01 first sensor group

[0421] -02 second sensor group

[0422] -03 semiconductor substrate

[0423] -10 magnetic source

[0424] -11 inner magnet portion

[0425] -12 outer magnet portion

[0426] -13 rotation axis

[0427] -14 centreline of the track formed by the outer magnet portion

[0428] -20 angular sensor assembly or angular sensor system

[0429] -50 sensor device (single packaged device)

[0430] -51 biasing and readout circuit

[0431] -52 processing circuit

[0432] -53 output circuit -54 non-volatile memory (e.g. flash)

[0433] -60 sensor device (single packaged device)

[0434] -70 sensor device (single packaged device)

[0435] -80 sensor device (single packaged device)

[0436] -90 sensor device (single packaged device)

[0437] -99 external processor, e.g. ECU

[0438] (other References:) sg sensor group sgl, sgNa first sensor group (see FIG. N) sg2, sgNb second sensor group (see FIG. N) sg3 third sensor group a first angle (derivable from signals from first sensor group)

[0439] P, 2 second angle (derivable from signals from second sensor group) 3 third angle (derivable from signals from third sensor group)

[0440] 0 absolute angle gc geometric centre ds distance between first and second geometric centre sp spacing between inner and outer magnet portion (if any) tw track width

[0441] Vi vertical Hall element (number i) vi signal from vertical Hall element Vi

[0442] Hi horizontal Hall element (number i) hi signal from horizontal Hall element Hi atan2 two-argument arctangent function

[0443] Bx,By,Bz magnetic field component oriented in the X-direction, Y-direction, Z-direction dBz / dx magnetic field component oriented in the Z-direction along the X-direction

[0444] DI, D2, D3 first, second, third diameter

[0445] Rl, R2, R3 first, second, third radius

Claims

Claims1. A sensor device (100; 1400) for determining an absolute angular position (9) of said device relative to a magnetic source (110; 1410) having an inner magnet portion (111, 1411) in the form of a magnetic dipole, and an outer magnet portion (112, 1412) in the form of a multipole ring magnet, wherein the sensor device comprises at least one semiconductor substrate defining a first and a second direction (X, Y) parallel to the semiconductor substrate, and a third direction (Z) perpendicular to the semiconductor substrate; the sensor device being a single packaged semiconductor device comprising:- a first sensor group (101; 1401) for measuring a first set of at least two magnetic field components or at least two magnetic field differences or gradients at a first sensor location (gel);- a second sensor group (102; 1402) for measuring a second set of at least two magnetic field components or at least two magnetic field differences or gradients at a second sensor location (gc2) spaced from the first sensor location (gel) by a predefined distance (ds);- output means for outputting the first and second set of signals, or one or more signals (Rl, R2, a, P, 9) derived therefrom, for allowing the determination of the absolute angular position (9).

2. A sensor device (100; 1400) according to any of the previous claims, wherein the first sensor group (101; 1401) is configured for measuring at least one of the following: i) at least two or three orthogonal magnetic field components (Bx, By; By, Bz) ii) a magnetic field component (Bx) oriented in the first direction (X) and a magnetic field component (By) oriented in the second direction (Y); iii) a magnetic field component (By) oriented in the second direction (Y) and a magnetic field component (Bz) oriented in the third direction (Z); iv) at least three orthogonal magnetic field components (Bx, By, Bz); v) at least three magnetic field components (Bzl, Bz2, Bz3) oriented in the third direction (Z); vi) at least four magnetic field components (Bzl, Bz2, Bz3, Bz4) oriented in the third direction; vii) at least two magnetic field differences or two magnetic field gradients (dBz / dx, dBz / dy).

3. A sensor device (100; 1400) according to any of the previous claims, wherein the second sensor group (102; 1402) is configured for measuring one of the following: i) at least two orthogonal magnetic field components (By2, Bz2); ii) a magnetic field component (By) oriented in the second direction (Y) and a magnetic field component (Bz) oriented in the third direction (Z); iii) at least three magnetic field components (Bzl, Bz2, Bz3) oriented in the third direction (Z);iv) at least three magnetic field components (Byl, By2, By3) oriented in the second direction (Y); v) at least three magnetic field components (Bxl, Bx2, Bx3) oriented in the first direction (X); vi) at least two sets of two orthogonal magnetic field components (By2,Bz2; By3,Bz3); vii) at least two sets of three orthogonal magnetic field components (Bx2,By2,Bz2; Bx3,By3,Bz3). viii) at least two magnetic field differences (diffl, diff2) or two magnetic field gradients (dBy / dy, dBz / dy; dBx / dy, dBz / dy).

4. A sensor device according to any of the previous claims, wherein at least one of the first sensor group and the second sensor group comprises an integrated magnetic concentrator (IMC) and a plurality of horizontal Hall elements arranged near a periphery of that integrated magnetic concentrator; or wherein each of the first sensor group and the second sensor group comprises an integrated magnetic concentrator (IMC) and a plurality of horizontal Hall elements arranged near a periphery of a corresponding integrated magnetic concentrator.

5. A sensor device according to any of the previous claims, wherein at least one of the first sensor group and the second sensor group comprises at least two Hall elements without an integrated magnetic concentrator (IMC); or wherein each of the first sensor group and the second sensor group comprises at least two Hall elements without an integrated magnetic concentrator (IMC).

6. A sensor device according to any of the previous claims, wherein the absolute angular position (9) is determined by: a) determining a coarse signal (Rl, a) based on the signals obtained from the first sensor group; b) determining a fine signal (R2, ) based on the signals obtained from the second sensor group; c) determining the absolute angular position (9) based on the coarse signal and the fine signal.

7. A magnetic source (110; 1410) comprising:- an inner magnet portion (111; 1411) in the form of a magnetic dipole;- an outer magnet portion (112; 1412) in the form of a multipole ring magnet.

8. A magnetic source (110; 1410) according to claim 7, wherein the ring magnet portion (112; 1412) is axially or axial-lateral magnetized.

9. A magnetic source (110; 1410) according to claim 7 or 8,wherein the ring magnet portion (112; 1412) has a single track of alternating magnetic poles.

10. A magnetic source (110; 1410) according to any of the claims 7 to 9, wherein the number of pole pairs of the ring magnet portion (112; 1412) is an even number.

11. A magnetic source (110; 1410) according to any of the claims 7 to 10, wherein the inner magnet portion (111; 1411) has a cylindrical shape; or wherein the inner magnet portion (111; 1411) has a prism shape with a polygonal crosssection.

12. A magnetic source according to any of the claims 7 to 11, wherein the outer magnet portion (112; 1412) has a ring shape with an inner radius R2 and an outer radius R3; and wherein (R2 / R3) is a value of at most 60%.

13. A magnetic source according to any of the claims 7 to 12, having one or more of the following features: wherein the inner magnet portion (111; 1411) as a cylindrical shape with an outer diameter of at most 5.0 mm; wherein the ring magnet portion (112; 1412) has an outer diameter of at most 12.0 mm; wherein the ring magnet portion (112; 1412) has a width in the radial direction in the range from 1.5 mm to 5.0 mm; wherein the inner magnet portion (111; 1411) and the outer magnet portion (112; 1412) are separated in a radial direction by a distance (sp) of at most 1.5 mm; wherein the inner magnet portion (111; 1411) and the outer magnet portion (112; 1412) are separated by a non-ferromagnetic material; wherein one or both of the inner magnet portion and the outer magnet portion are made of an isotropic material.

14. An angular position sensor system (120; 1420) comprising:- a sensor device (100; 1400) according to any of the claims 1 to 6;- a magnetic source (110; 1410) according to any of the claims 7 to 13; wherein the magnetic source is rotatable about a rotation axis; and wherein the sensor device is mounted such that its first sensor group is facing the inner magnet portion (111; 1411), and the second sensorgroup is facing the outer magnet portion (112; 1412).

15. A angular position sensor system (120; 1420) according to claim 14, wherein the sensor device (100; 1400) comprises a non-volatile memory for storing an angular offset value between the inner magnet portion (111) and the outer magnet portion (112), which value is determined during a calibration procedure; and wherein the absolute angular position (9) is determined taking into account the angular offset value stored in the non-volatile memory.

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