DE102007029819A1 - Sensor arrangement for use in e.g. automobile industry, has four magneto-resistive sensor elements e.g. anisotropic magneto resistance-sensor element, and three distances corresponded to smallest absolute phase differences of preset values - Google Patents

Abstract

The arrangement (110) has four magneto-resistive sensor elements (120) e.g. anisotropic magneto resistance-sensor element, where two sensor elements are proximately arranged in a distance. Other two sensor elements are proximately arranged in another distance. The first and third sensor elements are proximately arranged in third distance. Two distances correspond to smallest absolute phase difference of 1 degree or smaller than 90 degree in relation to a periodic magnetic field. The third distance corresponds to smallest absolute phase difference of 25 degrees. Independent claims are also included for the following: (1) a method for detecting section-wise periodic magnetic field produced or influenced by a transmitter object (2) a program with program codes executed by a processor to implement a method for detecting section-wise periodic magnetic field produced or influenced by a transmitter object.

Description

background

embodiments of the present invention relate to sensors and sensor assemblies, for example, for detecting magnetic field in a variety of Fields of technology can be used.

In In many fields of technology, information that is required for operation, for control and monitoring a machine or plant may be necessary in the form of magnetic Signals and information are provided. Therefore, in the Frame of the relevant equipment and machinery, for example, magnetic field sensors or other sensors that are capable of, the relevant information from the corresponding magnetic signals to extract. In other words, can appropriate sensors are used to generate magnetic signals to convert into electrical, allowing further processing, evaluation or processing allows becomes.

Examples for corresponding For example, information included in magnetic signals provides information in terms of a movement of objects, their position, theirs Acceleration or similar dynamic Sizes. In the automotive sector can for example, corresponding magnetic sensors and sensor arrangements can be used to angle, speed, directions of rotation, angular acceleration or gain other relevant information. Likewise, information can in terms of a linear or other curved movement in the space of a component another be detected by corresponding magnetic sensors.

Also in other areas of technology can use appropriate sensors can be used to corresponding, encompassed in magnetic signals To expose information. For example, the determination of levels, the Storage of magnetic information, its recovery or other sources of information count.

Frequently the relevant sensors in this case subjected to interference, the one accurate recording of the relevant information according to the specific Field of application and boundary conditions can disturb.

Summary

One embodiment a sensor arrangement for detecting a generated by a donor object or influenced periodic magnetic field comprises a first, second, third and fourth magneto-resistive sensor element, wherein adjacent the first and second magnetoresistive sensor elements are arranged at a first distance, wherein the third and the fourth magnetoresistive sensor element adjacent in a second Distance are arranged, wherein the first and the third magnetoresistive Sensor element are arranged at a third distance, wherein the first distance and the second distance a smallest absolute phase difference based on the periodic magnetic field of at least 1 ° and less correspond to 90 ° and wherein the third distance is a smallest absolute phase difference of at least 25 °.

One embodiment a sensor arrangement for detecting a generated by a donor object or influenced periodic magnetic field comprises a first, second and third magnetoresistive sensor element, wherein the first and the second magnetoresistive sensor element adjacent in one first spaced, the second and the third magnetoresistive sensor element arranged at a second distance are, with the first distance a smallest absolute phase difference based on the periodic magnetic field of at least 1 ° and less correspond to 90 ° and wherein the second distance is a smallest absolute phase difference of at least 25 °.

An embodiment of a sensor arrangement for detecting a periodic magnetic field generated or influenced by a donor object comprises a first, second, third and fourth magnetoresistive sensor element, wherein the first and the second magnetoresistive sensor element are arranged at a first distance, wherein the second and the third magnetoresistive sensor element are arranged at a second distance, wherein the third and the fourth magneto-resistive sensor element are arranged at a third distance, wherein the first distance and the third distance corresponds to a smallest absolute phase difference relative to the periodic magnetic field of at least 20 ° and wherein the second distance a smallest absolute phase difference related to the periodic magnetic field of at most 40 ° corresponds.

An embodiment of a sensor arrangement for detecting an at least sectionally periodic magnetic field generated or influenced by a sensor object comprises first, second, third and fourth magnetoresistive sensor elements, wherein the first and the second magnetoresistive sensor elements are arranged adjacent to one another at a first distance, the third and the third magnetoresistive sensor element fourth magnetoresistive sensor element are arranged adjacent at a second distance, wherein the first and the third magneto-resistive sensor element are arranged at a third distance, wherein the first distance ( 400 ) and the second distance ( 410 ) at least 1% of the third distance ( 420 ) and less than 50% of the third distance ( 420 ) is.

One embodiment a sensor arrangement for detecting a generated by a donor object or influenced at least partially periodic magnetic field has a first, second and third magnetoresistive sensor element wherein the first and second magnetoresistive sensor elements are adjacent are arranged at a first distance, wherein the second and the third magnetoresistive sensor element arranged at a second distance and wherein the first distance is at least 1% of the second distance and less than 50% of the second distance.

One embodiment a sensor for detecting a generated by a donor object or influenced at least partially periodic magnetic field includes first, second, third and fourth magnetoresistive Sensor element and an evaluation circuit that is configured to based on a first difference signal of the first and the second magnetoresistive sensor element and based on a second difference signal of the third and the fourth sensor element to provide a sum signal and a difference signal, wherein the sum signal is information relating to a speed of the encoder object, and wherein the difference signal is an information in terms of a direction of the donor object, wherein the first and the second magnetoresistive sensor element arranged at a first distance are, wherein the second and the third magneto-resistive sensor element are arranged at a second distance and wherein the third and the fourth magnetoresistive sensor element is arranged at a third distance are.

Brief description of the figures

embodiments The present invention will be described below with the aid of the following Figures described.

1 shows an application scenario of embodiments of sensors and sensor arrangements;

2 shows another scenario of a field of application of embodiments of a sensor or a sensor arrangement;

3 shows another application scenario of embodiments of sensors and sensor arrangements;

4 shows a block diagram of an embodiment of a sensor or a sensor arrangement;

5 schematically shows a phase relationship of signals of in 4 shown embodiment;

6a shows an equivalent circuit diagram of a half-bridge circuit;

6b shows an equivalent circuit diagram of a full bridge circuit;

7 shows a block diagram of another embodiment of a sensor or a sensor arrangement;

8th shows a further block diagram of another embodiment of a sensor or a sensor arrangement;

9 shows a block diagram of an embodiment of a sensor or a sensor arrangement;

10 shows a further block diagram of a further embodiment of a sensor and a sensor arrangement;

11 shows a block diagram of another embodiment of a sensor and a sensor arrangement with two gradiometers;

12 schematically shows two waveforms of signals from sensor elements of in 11 shown embodiment; and

13 schematically shows further courses of signals of in 11 shown embodiment of a sensor or a sensor arrangement.

Detailed description the embodiments

The 1 to 13 show block diagrams, application examples and waveforms of embodiments of sensors and sensor assemblies. Before in connection with the 4 to 13 Embodiments of sensors and sensor arrangements will be described initially in connection with the 1 to 3 various applications, application examples and principles of possible applications of embodiments of a sensor or sensor arrangement described.

1 shows a first schematic representation of a possible application scenario of an embodiment of a sensor 100 , The sensor 100 includes embodiments of a sensor arrangement 110 with a plurality of magnetoresistive sensor elements 120 , More specifically shows 1 an embodiment of a sensor 100 in which the sensor arrangement 110 is shown in cross-section, wherein for simplicity of illustration, only two individual magnetoresistive sensor elements 120 are shown.

On a back of the sensor 100 is a so-called backbias magnet 130 attached, the sensor 100 or the magnetoresistive sensor elements 120 a temporally (constant) magnetic field or a magnetic flux density exposes. The backbias magnet 130 This is often designed as a permanent magnet, the one through the in 1 has arrows indicated magnetization. Together with the embodiment of the sensor 100 , its sensor array 110 and the magnetically sensitive elements 120 is the backbias magnet 130 in a protective housing 140 embedded or even shed.

The backbias magnet 130 sets the sensor 100 with its magnetoresistive sensor elements 120 a temporally constant magnetic field or a temporally constant magnetic flux density, for example, by a donor object 150 then in dependence of a movement of another object, that with the donor object 150 mechanically coupled or connected is affected. At the in 1 shown application example is the encoder object 150 For example, designed as a toothed wheel, which may be mechanically connected or mechanically coupled to a rotating component or itself may be designed as part of the object in question. Here is the donor object 150 based on the magnetoresistive sensor elements 120 arranged at a distance, which is also referred to as a magnetic air gap (magnetic air gap) or as an air gap. This one is in 1 indicated by a double arrow.

The donor object, which is sometimes referred to as a permeable target wheel, often has a periodic structure on its circumference or by some other topology that results in a case of movement, such as rotation of the gear 150 , the magnetoresistive sensor elements 120 a periodically periodic magnetic field or a temporally periodic magnetic flux density are exposed.

In addition to the previously described gear, a donor object may alternatively or additionally also be embodied as a pinwheel or pole wheel, wherein a pole wheel may have, for example, periodically arranged regions of an alternating magnetization on its outer circumference. In other words, in the case of a pole wheel on its circumference magnetic regions may be arranged such that, for example, north poles and south poles are arranged periodically alternately. Such an example will be related to 2 explained in more detail.

In addition, the donor object can 150 be executed in the case of a linear movement or in the case of a movement to be detected as a linear movement as a rack, hole bar or pole rod, in which case again the rod in question often has a periodic structure at its periphery, which is suitable that of back-bias magnet 130 caused magnetic field in response to a movement of the respective donor object 150 periodically to modulate or change, so that an embodiment of a sensor 100 can detect this movement by detecting the periodic change of the magnetic field or by the measurement of the magnetic field.

As previously indicated, respective embodiments of sensors 100 For example, be used in the automotive sector. In the case of ABS systems (ABS = anti-lock braking system), for example, the movement of the wheels by means of embodiments of magnetic sensors 100 be detected. In such a case, for example, the donor object 150 be coupled directly to the wheel, an associated shaft or other component that moves according to the movement of the wheel. In the case of a driven wheel, for example, the donor object 150 be mechanically coupled to an output of a differential.

In the field of engine technology, corresponding embodiments of a sensor 100 be used in the range of crankshaft sensors and / or camshaft sensors, which can be used for example for detecting a rotation of the respective waves. Accordingly, examples of embodiment of a sensor can be made 100 also be used in other waves, such as in the transmission range for measuring a speed at an output of the transmission. Depending on the concrete implementation of corresponding embodiments, in particular with regard to different technologies in the field of magnetoresistive sensor elements 120 For example, embodiments of corresponding sensors 100 in the form of incremental GMR velocity sensors (GMR = Giant Magneto Resistance).

As has already been explained, in this case often either pole wheels with permanently magnetized patterns or gears as donor objects are used 150 with small permanent magnets 130 at the back of the embodiments of sensors 100 used. In both cases, it is caused by a movement of the wheel, more precisely by the movement of the encoder object 150 , on the sensor 110 a periodic, often sinusoidal or sinusoidal magnetic field. Be used instead of magnetoresistive sensor elements 120 Used Hall probes, in this case, the component is meant perpendicular to a chip or a substrate on which the respective Hall probes are manufactured or prepared. In the case of magnetoresistive sensors (xMR sensors), in general, a component parallel to the chip plane or the component is parallel to a main surface of the substrate or chip.

In the context of the present application, magnetoresistive sensor elements, that is to say, for example, the magnetoresistive sensor elements, are included here 120 For example, so-called AMR sensor elements (AMR = Anisotropic Magneto Resistance = Anistroper magnetoresistance), GMR sensor elements (GMR = Giant Magneto Resistance), CMR elements (CMR = Colossal Magneto Resistance), TMR sensor elements (TMR = Tunnel Magneto Resistance), EMR (Extraordinary Magneto Resistance) sensor elements or spin valve sensor elements (Spin Valve Sensor Elements). Depending on the technology used, corresponding magnetoresistive sensor elements have a different layer structure. In some cases, for example in the case of GMR sensor elements or TMR sensor elements, these have a soft-magnetic layer and a hard-magnetic layer, wherein the hard-magnetic layer can be embodied, for example, as a synthetic antiferromagnet (SAF), which has magnetic field strengths or their components with respect to a preferred direction can detect this preferred direction. In the case of GMR sensors, those to the GMR sensors very related spin valve structures, and in the case of TMR structures, such a synthetic antiferromagnet, for example, by a so-called conditioning process in which the structure in question above a blocking temperature designated temperature is heated and in a magnetic field of the respective direction, which coincides with the preferred direction, are cooled again. As a result, the relevant magnetic field is "inscribed" in the relevant sensor.

ever according to the structure used or depending on the sensor element technology used can other measures, For example, the design or the layout, to be taken to define a corresponding preferred direction. In the case of GMR structures, spin valve structures and TMR structures often lie parallel to the main surface of the Substrate or the chip on which they were prepared or deposited.

1 shows an example of an embodiment of a sensor 100 with an embodiment of a sensor arrangement in the case of a conventional application. This is a small permanent magnet as a backbias magnet 130 to the sensor 100 attached to generate a magnetic field. Both will then be in front of the donor object 150 , For example, a toothed, permeable disc placed.

Will the disc then, as in 1 indicated by the arrow, rotates, the teeth of the disc pass an area in front of the sensor 100 and thus generate a small magnetic field variation or a small variation of the magnetic flux density, which then passes through the embodiment of the sensor 100 can be detected. This field variation can, for example, information about the angular position and / or the rotational speed of the disc (encoder object 150 ). Furthermore, depending on the specific embodiment of a sensor 100 in the variation of the magnetic field further information, for example, the direction of rotation may be included. A waveform of the variation of the magnetic field or the magnetic flux density caused by the rotation of the encoder object 150 is in many cases sinusoidal or nearly sinusoidal. In this case, it may be particularly advisable, at least over a region of the circumference of the gear or a comparable dimension of other donor objects 150 to periodically execute the corresponding structures or magnetizations so that in general the waveform is periodic in such a case. An amplitude of the magnetic field variation decreases drastically with increasing air gap.

Depending on the concrete implementation of an embodiment of a sensor 100 , it may also be advisable to achieve increased insensitivity to homogeneous background fields, which can be found on the relevant chip of the sensor 100 At least two sensors are at a distance that corresponds to approximately 50% of the tooth period, which is also referred to as pitch. In many application examples, are often used as conventional gears, those having a period of 5 mm, so it so in the case of an embodiment of such a gear as a donor object 150 can be advisable, the two magnetoresistive sensors 120 spaced apart from each other at a distance of about 2.5 mm, as shown in FIG 1 outlined.

Their signals can be subtracted from each other, for example, by the use of a half-bridge circuit, but also using other technical implementations. Due to the distance between both sensors 120 are their signal waveforms (sinusoidal signals) about 180 ° out of phase. A subtraction thus approximately doubles its amplitude. In other words, one gains signal strength through the use of a corresponding circuit. In addition, in the case of a corresponding interconnection, it is also advantageous in the case of some exemplary embodiments that homogeneous incidents occur on both magnetoresistive sensor elements 120 act in the ideal case, largely suppressed or eliminated due to the subtraction in the difference formation. The subtraction of the two signals can, as previously indicated, for example, by a bridge circuit in the form of a half-bridge circuit (H-bridge) directly in the field of the embodiment of the sensor 100 or in the region of the embodiment of the sensor arrangement 110 happen. In principle, however, it is also possible to perform a corresponding signal subtraction only in the subsequent signal processing, for example in the context of an evaluation circuit. As will be explained later, however, the variant explained first may provide better results in some applications and embodiments. Such a sensor configuration is also called a gradiometer, because due to the subtraction of two spatially separated signals in the case of a sufficiently small spacing of the two sensor elements 120 to one another a component of a gradient of the relevant magnetic field or the magnetic flux density, proportional signal is generated. Accordingly, embodiments of a sensor 100 having a corresponding gradiometer configuration, also referred to as differential magnetic field sensors.

In some embodiments of a sensor 100 In addition, to determine the direction of rotation of the encoder object 150 , one or more additional sensors are used. So you want to know at the same time, whether the wheel in question 150 Turning to the left or to the right, it may be advisable to provide an additional magnetoresistive sensor element at a third location on the substrate or chip.

In other words, in the context of some embodiments of a sensor 100 or in the context of some embodiments of a sensor arrangement 110 Gradiometer configurations or Gradiometer arrangements are used, which are able to detect a difference of magnetic flux or magnetic flux densities with respect to two spaced points and detect. In contrast to this, a single magnetoresistive sensor element can detect the magnetic field or the correspondingly prevailing magnetic flux density only in a single point, so that a single magnetoresistive element is thus only able to detect an absolute field strength or an absolute information regarding the magnetic flux density , Such a signal of a single magnetoresistive sensor element can therefore particularly sensitive to superimposed disturbances of the magnetic field, which act from the outside on the system in question, since they often can not be distinguished from the useful signal. Depending on the specific application example of an embodiment of a sensor 100 or a sensor arrangement 110 Therefore, a signal detection can be improved by a gradiometric arrangement of the sensor elements (for example in the form of bridge circuits) are used, since at least two sensor elements acting, rectified interference by subtraction are at least partially eliminated or compensated.

It should be noted that in the 1 . 2 and 3 shown geometries of embodiments of sensors 100 only to be understood schematically. This shows in particular 1 as explained, two magnetoresistive sensor elements. Both in terms of the number of magnetoresistive Sen sorelemente as well as their positioning relative to the backbias magnet 130 and / or an optional donor object 150 are the ones in the 1 to 3 selected representations are not complete or exhaustive. As part of the 1 to 3 Rather, only different application examples are sketched in which the individual magnetoresistive sensor elements 120 , An embodiment of a sensor 100 and the sensor assembly 110 one through the donor object 150 Periodically influenced or generated magnetic field are subjected, which can be detected and detected by the aforementioned embodiments. In other words, that means that in the 1 to 3 shown magnetoresistive sensor elements or their positions only to illustrate application areas and for the fundamental introduction with regard to the periodically influenced or generated magnetic field by the encoder object 150 optionally in connection with the backbias magnet 130 serve. Detailed descriptions of embodiments 100 and a sensor arrangement 120 be related to the 4 to 13 follow later.

2 shows a further field of application or a further application of an embodiment of a sensor 100 or a sensor arrangement 110 , Here is in 2 a corresponding sensor arrangement for two different times (t1) and (t2) is shown, wherein with respect to the time (t2) once an arrangement of the relevant embodiment of a sensor arrangement 110 for a left turn (t2 _L ) and for a right turn (t2 _R ). 2 also shows another type of donor object 150 that was explained earlier. More specifically, it is the donor object 150 to a magnetic wheel or a magnetic wheel, which is also referred to as a flywheel. At its periphery, the pole wheel 150 a plurality of periodically arranged magnetic regions 160-S . 160-N following the use of the reference symbol as south pole (S) and north pole (N), respectively. The pole wheel 150 thus generates in Be rich its surface, ie in the range of magnetic regions 160 magnetic field lines 170 as they are in 2 are drawn.

With regard to the sensor arrangement 110 these are, as explained above, with respect to the two times t1, t2 shown. The sensor arrangements 110 are here with respect to three places or with respect to three different positions 180-1 . 180-2 . 180-3 shown. At time t1, the pole wheel exercises 150 as donor object 150 on one at position 180-1 arranged first magnetoresistive sensor element due to the field lines 170 an effect represented by a plus sign (+). On a second magnetoresistive sensor element at position 180-2 will be according to the reverse direction of the corresponding field lines 170 a correspondingly rotated by 180 ° magnetic field, so that the magnetic field exerts an influence on this magnetoresistive sensor element, which is indicated by a minus sign (-). A third magnetoresistive sensor element at position 180-3 between the two positions 180-1 . 180-2 On the other hand, it is located in an area where no magnetic field acts in the configuration shown, so that the corresponding effect is represented by a number 0.

Now in the context of a left turn the encoder object 150 moves, the situation arises with respect to the sensor arrangement 110 and the donor object 150 as determined by the location of the sensor array 110 at the time t2 _L is playing. In this case, acts on the first magnetoresistive sensor element and the second magnetoresistive sensor element at the positions 180-1 . 180-2 in the horizontal direction, no magnetic component, so that the magnetic field on the relevant magnetoresistive sensor elements exerts no influence, which is represented by the numeral 0. In contrast, the third, middle magnetoresistive sensor element is at position 180-3 exposed to a magnetic flux density, which leads to an influence in 2 by a (-) play. Accordingly, there is also a situation in the case of a clockwise encoder object 150 as reproduced in the sub-figure below. More precisely, again the first and the second magnetoresistive sensor element act here 120-1 . 120-2 in the horizontal direction no magnetic flux lines on this one, so that the effect of the magnetic field on these two sensor elements is again represented by the numeral 0. Unlike the case However, a left-handed encoder object now prevails in the region of the third magnetoresistive sensor element 120-3 a magnetic field that leads to a positive effect in 2 represented by a (+). This already shows that by using a third magnetoresistive sensor element 120 between the two outer magnetoresistive sensor elements 120-1 . 120-3 an information regarding a direction of the rotation of the encoder object 150 is derivable.

When using embodiments of a magnetic field sensor 100 or a sensor 100 For incremental velocity measurement, in some cases rotating, magnetized magnetic wheels or metal gears are used as donor objects 150 which optionally uses the box one behind the actual sensor 100 attached magnets 130 distract or modulate. In the case of a pole wheel as a donor object 150 like this in 2 is shown, the measurement of the speed can be done for example by detecting the zero crossings of the differential field, as for example by the outer magnetoresistive sensor elements at the positions 180-1 . 180-2 at the in 2 shown configuration can be done. Such a differential field can be detected if two magnetic field sensor elements, for example two Hall sensor elements or magnetoresistive sensor elements (for example GMR sensor elements) are placed at a distance of a magnetic pole length or a tooth length in the relevant magnetic field.

In addition, in many or some applications, it may be necessary or advisable, in addition to the speed of the rotating encoder object 150 , So for example, the wheel or a wave, to recognize the direction of rotation. This is the case for example in the case of ABS sensors, crankshaft sensors, camshaft sensors or transmission speed sensors in the automotive sector.

So shows 3 schematically the use of a sensor module 190 , with an embodiment of a sensor and a sensor arrangement 110 , as described and explained in more detail in the further course of the present application. More precisely, shows 3 an application of a corresponding embodiment of a sensor 100 (not shown in 3 ), in the context of the sensor module 190 is included, in the case of an engine 200 who in 3 is shown schematically in cross section. As donor object 150 In this case, a gear is used with the crankshaft of the engine 200 mechanically connected or coupled.

The gear as a donor object 150 here has an index gap 210 in which at least one tooth of the gear is not executed. This makes it possible to determine a certain angular position of the crankshaft by the modulation of the magnetic field passing through the encoder object 150 is caused, is disturbed by the fact that a deviating from the other periodicity signal is generated.

3 shows so inside a motor housing 220 a cross section through a cylinder by a piston 230 moved, over a connecting rod 240 is mechanically coupled to the crankshaft. 3 also shows in the area of a cylinder head 250 in cross-section an inlet channel 260 , an outlet channel 270 , each from a valve 280 a common combustion chamber 290 above the piston 230 split off. A spark plug 300 and an injection nozzle 310 are also in the cylinder head 250 attached, that these also in the combustion chamber 290 protrude. In addition, in 3 different coolant areas 320 with a temperature sensor 330 shown. 3 Thus shows an insert of an embodiment of a sensor or a sensor arrangement 110 in the context of the sensor module 190 as a crankshaft sensor. Accordingly, similar sensor modules can also be used in the area of the camshafts, which are the valves 280 drive.

4 shows a first embodiment of a sensor 100-1 with an embodiment of a sensor arrangement 110-1 and an evaluation circuit 350 that with the embodiment of the sensor arrangement 110-1 is coupled. More specifically, the sensor assembly includes 110-1 four magnetoresistive sensor elements 120-1 , ..., 120-4 of which two each have a node 360-1 . 360-2 in series between a supply line 370 for a positive supply voltage (eg Vbridge +) and a supply line 380 are connected for a negative supply voltage (eg Vbridge-). The positive supply voltage Vbridge + can, for example, from a positive supply voltage of the sensor 100-1 derived voltage or it may be the corresponding supply voltage of the sensor itself. Accordingly, depending on the concrete implementation of an embodiment, the negative supply voltage Vbridge, via the supply line 380 the sensor elements 120 is made available, based on a reference potential negative external supply voltage, a voltage derived from such a voltage or else a reference potential, so for example Ground (GND).

The two magnetoresistive sensor elements 120-1 . 120-2 are each with a connection to the supply line 370 coupled with their second connector each at a node 360-1 . 360-2 are coupled. The other two magnetoresistive sensor elements 120-3 . 120-4 are similarly coupled with a connection to the two aforementioned nodes, with their respective other connection, but with the supply line 380 coupled. This is how the magnetoresistive sensor elements form 120-1 and 120-3 over the node 360-1 a half-bridge circuit, while the magnetoresistive sensor elements 120-2 and 120-4 along with the node 360-2 form as a corresponding center tap another half-bridge circuit. In 4 are the two resulting half-bridge circuits within the relevant magnetoresistive sensor elements 120 marked with the numbers 1 and 2. In other words, the four magnetoresistive sensor elements form 120-1 to 120-4 a total of two sensor bridges, which via their center taps in the form of nodal points 360 with the evaluation circuit 350 are coupled.

With regard to an arrangement of the magnetoresistive sensor elements 120 on a substrate or chip on which the corresponding sensor arrangement 110 For example, in the form of a thin film or thin film device can be realized, shows the horizontal arrangement of the four sensor elements 120 a possible arrangement on the relevant chip or substrate. In other words, an arrow illustrates 390 an x-axis, which is at the same time a main detection direction of the embodiment of the sensor arrangement 110-1 or the sensor 100-1 represents. In contrast to this, the in 4 this vertical direction not in the sense of orientation or arrangement of the relevant magnetoresistive sensor elements 120 to understand on the chip or the substrate. The to the main detection direction 390 vertical in 4 shown spatial direction rather serves for a clearer representation of the half-bridge circuit. In many cases of embodiments of a sensor arrangement 110 or a sensor 100 rather, the four magnetoresistive sensor elements 120-1 to 120-4 parallel to a line not correspondingly drawn in FIG. 1 with respect to the main detection direction 390 arranged.

The first two magnetoresistive sensor elements 120-1 . 120-2 are further here, based on the main detection direction 390 , so for example an x-axis, at a first distance 400 arranged. While the third and fourth magneto-resistive sensor element 120-3 . 120-4 at a second distance 410 and the first and third magneto-resistive sensor elements 120-1 . 120-3 are arranged at a third distance from each other.

Depending on the specific embodiment of an embodiment of a sensor 100 Here are the individual distances 400 . 410 . 420 be defined relative to each other. For example, if the base distance is the third distance 420 defined, so can the first and the second distance 400 . 410 For example, in some embodiments, a fraction of this base distance may be indicated. In embodiments of the present invention, such are the first and second distances 400 . 410 less than 50% of the third distance, but greater than 1% of the third distance in question 420 , In further embodiments, furthermore, the first and the second distance can 400 . 410 based on the third distance 420 in a range between 1%, 2% and 5%, respectively, as the lower limit of the corresponding range and less than 40%, 30%, 20% or 10% of the relevant third distance 420 lie.

In many cases, corresponding embodiments of sensors 100 designed or optimized for a corresponding field of application. As previously explained, embodiments of sensors often become associated with a donor object 150 used, which provides at least partially spatially and / or temporally generated or be influenced periodic magnetic field due to its outer dimensions or over the outer dimension at least partially periodically distributed structures. In such a case, the third distance is generally based 420 on a characteristic distance, a characteristic length or a characteristic dimension of the encoder object 150 , For example, the third distance may be about a tooth length, a gap length, or another characteristic length of at least a portion of the outer dimension of the encoder object 150 distributed periodic structures correspond or at least based on these. For this reason, a description of the positioning of the individual sensor elements with respect to a corresponding at least partially periodic magnetic field is very often carried out not least to simplify the representation and the functional relationships below. Of course, the individual occurring within the scope of the further embodiments, individual distances to another distance of the relevant embodiments may be related. For example, in the case of 4 embodiment shown on the assumption that the third distance 420 with an accuracy of less than 20%, 10% or 5% of the half of the pitch of the donor object 150 corresponds to corresponding distances as phase differences to the third distance 420 be obtained. The same applies to the other explained in the context of the present application embodiments. Relative to one of a donor object 150 Thus, the spatially periodic magnetic field generated or influenced may correspond to the first distance to a smallest absolute phase difference that is greater than 1 ° and less than 90 °.

Also, the third and fourth magneto-resistive sensor elements adjacent to each other in the second distance 410 are arranged, this distance also corresponds to the main detection direction 390 and to the at least partially periodic magnetic field a smallest absolute phase difference, which is greater than or equal to 1 ° and less than 90 °. While the first and the second magnetoresistive sensor element 120-1 and 120-2 and the third and fourth magneto-resistive sensor elements 120-3 . 120-4 Thus, each adjacent to each other, is the first magnetoresistive sensor element 120-1 and the third magnetoresistive sensor element 120-3 in the third distance 420 arranged, which in turn related to the main detection direction 390 and the periodic magnetic field corresponds to a minimum absolute phase difference of at least 25 °.

In this context it should be pointed out that due to the periodicity of phases of periodic objects, effects, gradients, fields or magnetic fields, phase differences corresponding to one or several whole periods (360 °) can be arbitrarily subtracted or added without an influence on the resulting physical system to take. Due to the periodic nature of the magnetic field, as it is generated or influenced by the encoder object, this also applies to magnetic fields from a donor object 150 generated or influenced as long as this happens periodically. For this reason, for example, a phase difference of 190 ° corresponds to a smallest distance of 170 ° (= | 190 ° -360 ° |) because, as previously explained, any one-line multiple of a phase difference of 360 ° corresponding to one period is added or subtracted can be. In other words, for any phase difference that is less than 0 ° or greater than 180 °, there is a smallest absolute phase difference that is in the interval between 0 ° and 180 °. Expressed in formal terms, this means that, for each phase difference φ, there is a smallest absolute phase difference α in the interval between 0 ° and 180 ° that corresponds to the equation α = | φ - m · 2π | enough. Here m is an arbitrary integer.

Moreover, in many embodiments of sensor arrangements 110 and sensors 100 the corresponding magnetoresistive sensor elements 120 arranged according to their numbering on the substrate or chip. So are in many embodiments, like this 4 in terms of an x-coordinate according to the main detection direction 390 the second magnetoresistive sensor element on a same side of the magnetoresistive sensor element 120-1 arranged as the fourth magnetoresistive sensor element 120-4 with respect to the third magnetoresistive sensor element 120-3 , In other words, the second magnetoresistive sensor element is arranged in a predetermined direction relative to the first magnetoresistive sensor element and the fourth magnetoresistive sensor element 120-4 with respect to the third magnetoresistive sensor element 120-3 also arranged in the predetermined direction.

In many embodiments of a sensor arrangement 110 or a sensor 100 are beyond the first distance 400 and the second distance 410 essentially the same size. In other words, in many embodiments, the first distance and the second distance, possibly taking into account, for example, a process-related positioning tolerance are equal. Depending on the specific implementation of the individual magnetoresistive sensor elements, that is to say in particular with regard to the technology used, the distances are defined, for example, with regard to a center point of the relevant sensor elements, that is, for example, a centroid or another similarly defined point. In the case of meander-shaped sensor elements, for example, a base point, based on the distances 400 . 410 . 420 are defined for the individual magnetoresistive sensor elements 120 be given that a focal point of gravity, a centroid, a center or another prominent or predetermined point is used. In this context, it is in egg nigen embodiments of a sensor arrangement 110 or a sensor 100 helpful if in the case of identical or similarly shaped magnetoresistive sensor elements 120 the respective base points are chosen equal or identical.

Regarding the periodicity of the magnetic field that passes through the donor object 150 can be generated or influenced, it should be noted that the period, or more precisely, the spatial period significantly by the period of the relevant donor object 150 can be determined. In other words, in many applications, one embodiment of a sensor is 100 or a sensor arrangement 110 the (spatial) period by, for example, the pitch of the donor object 150 So, for example, the distance between two teeth in the case of a gear as a donor object 150 Are defined. In addition, it should be noted that due to the rotation or generally addressed the movement of the donor object 150 the spatial periodicity of the periodic magnetic field or of the encoder object 150 is transformed into a temporal periodicity over a corresponding speed. Depending on the specific implementation, in the case of speed, for example, it may be an angular velocity ω or a linear velocity v. Based on a phase angle or phase difference φ, this results in the case of a rotation of the encoder object 150 a phase difference φ = w · t (1) and in the case of a linear velocity, a phase difference φ = v · t / λ, (2) where λ is the pitch or the periodicity of the corresponding encoder object 150 and t represents the time. Depending on the concrete implementation of a donor object 150 This can also lead to an interruption of the periodicity of the encoder object 150 come considered as a whole. For example, like this 3 has shown an index gap 210 or integrating an index tooth in a corresponding encoder object, for example, to mark a particular angular position or another particular position. In such a case, of course, the statements made above with regard to the periodicity, the phase differences and other related variables may, if necessary, be limited to a range of the respective index tooth or the corresponding index gap 210 not included. In general, however, this is not a serious limitation since the periodicity of, for example, that of the donor object 150 Periodic magnetic field generated or influenced refers to a much smaller period, namely the pitch or the tooth spacing. A lack of one or more corresponding teeth, ie the presence of an index gap 210 Although the periodicity of the total donor object 150 but can be neglected or disregarded, since in application examples a corresponding periodicity over a certain range, not the entire encoder object 150 must be sufficient.

Thus, a corresponding donor object has an index gap 210 or a corresponding other marking, however, this leads at least to a sectionally periodic magnetic field or generates this. For example, with crankshaft sensors, which are an essential application for directional speed sensors (speed sensors), use of gears or pulleys where a longer portion serves as the absolute position marker is quite common. For this purpose, for example, a gap between two teeth is omitted so that this portion becomes a total of three times longer. If a phase shift is now considered, this differs from this absolute position marking by a phase shift that is defined with respect to the teeth or the other structures of the relevant encoder object. However, this is not a problem in the present case, since, apart from the range of absolute position marking (for example, the index gap 210 ) the modification or influence of the magnetic field caused by the encoder object is periodic at least in the area outside the index gap with respect to the shorter period length. Thus, therefore, a magnetic field also caused or influenced by such a donor object is at least partially periodic.

Accordingly, of course, a definition or definition of the distances of the individual sensor elements 120 to each other in this embodiment, as well as in the other embodiments of the present invention, are defined with respect to the encoder object. Thus, for example, the distances in question can also be related to distances of the encoder object, that is, for example, a length of a tooth, a length of a gap, or another object arranged on the outer edge of the encoder object. Of course, the distances in question can also be defined relative to each other, for example when a distance, such as the third distance at the in 4 shown embodiment is based on a characteristic length, which depends either on the (at least partially) periodic magnetic field or the corresponding encoder object.

In other words, the donor object 150 at least over part of an outer dimension of the Encoder object distributed periodic structures that are able to generate or influence an at least partially periodic magnetic field. Corresponding structures include teeth, holes, voids, magnetic regions, and regions of different magnetization.

With regard to the phase differences of the distances of the first, second and third distances 400 . 410 . 420 It should be noted that in further embodiments of a sensor 100 or a sensor arrangement 110 the first and the second distance 400 . 410 depending on the exact engineering implementation details may be in a phase range between 5 ° and 20 ° or 10 ° to 20 °. Depending on the specific implementation, the first distance and the second distance between the sensor elements 120-1 and 120-2 respectively. 120-3 and 120-4 also correspond to phase differences between 2 ° -80 °, 2 ° -40 °, 2 ° -20 °, 5 ° -80 °, 5 ° -40 ° or 5 ° -20 ° relative to the at least partially periodic magnetic field. With regard to the phase differences, the third distance 420 Depending on the concrete implementation, it may be the third distance 420 a phase angle of at least 90 °, of at least 120 ° or of at least 160 °. Accordingly, the third distance may correspond to a phase difference in some embodiments of at least 40 °, 80 °, 110 ° or 150 °. In some embodiments of a sensor arrangement 110 or a sensor 100 can the magnetoresistive sensor elements 120-1 and 120-3 be arranged at a distance corresponding to a phase difference of 180 ° +/- 5 ° or 180 ° +/- 2 °.

In the case of an embodiment of a sensor 100-1 , next to the sensor array 110-1 also the evaluation circuit 350 For example, it may be configured to be based on a first difference signal of the first and third magnetoresistive sensor elements 120-1 . 120-3 at the node acting as the center tap 360-1 the relevant half-bridge circuit can be tapped, and based on a second difference signal of the second and fourth magnetoresistive sensor element 120-2 . 120-4 at the node acting as the center tap 360-2 This half-bridge circuit is available to provide a sum signal and a difference signal. The sum signal may in this case in formations with respect to a speed of the encoder object, which result, for example, from a frequency of the sum signal itself. Accordingly, the difference signal may be information regarding a direction of rotation or direction of the speed of the encoder object 150 exhibit. Such information may, for example, result in a value of the difference signal at a specific time, which can be derived on the basis of the sum signal, for example. Depending on the concrete implementation of an evaluation circuit 350 Thus, the sum signal and / or the difference signal itself or the information obtained therefrom, for example, at one or more outputs of the evaluation circuit 350 be made available for later processing.

In one embodiment of a sensor 100-1 or a sensor arrangement 110-1 Thus, two only slightly offset bridges with the magnetoresistive sensor elements 120-1 . 120-3 and 120-2 . 120-4 used. This allows both signals of the two bridges at the junctions 360 can be tapped, used for zero point detection. A sampling of the respective two signals or differential signals can, as will be explained below, be multiplexed. By doubling the sampling rate in the case of digital or analog processing of the two differential signals by the evaluation circuit 350 Compared to an implementation of only a single half-bridge, a moving averaging can be carried out, for example, which can lead to an improvement of the signal-to-noise ratio.

The averaged signal or the sum signal corresponds to a virtual sensor which is arranged between the two individual sensors, more precisely between the two half-bridge circuits. The difference signal, based on the at the two nodes 360-1 . 360-2 tappable difference signals from the evaluation circuit 350 can be obtained, so information on, for example, by one between the magnetoresistive sensor elements 120 a half-bridge circuit located further sensor can be determined. Such another sensor in the middle of such a sensor integrated circuit (IC) would provide a 90 ° phase shifted signal against one of the (difference) signals from two of the outer sensor elements (eg sensor elements 120-1 . 120-3 or 120-2 . 120-4 ) deliver. Depending on the direction of rotation would then at a zero point of the difference signal at one of the nodes 360 such a signal of a center sensor has a minimum or a maximum. In conjunction with a derivative of the difference signal, at one of the nodes 360 can be tapped, could then give the sign of an extremum of the differential signal information about the direction of rotation, for example, if a zero point of the signal of such a middle sensor is evaluated.

If a correspondingly placed third sensor element lies in the middle between two external sensors Elements on the chip, there are signals of the three individual sensor elements, which are each phase-shifted by 90 ° to each other. By interconnecting the two outer sensor signals in the form of a half-bridge circuit, these are subtracted and a corresponding difference signal, which at a node 360 can be tapped, can be referred to as a speed signal or as a speed signal accordingly. An optional central sensor would provide a corresponding direction signal, referred to as a director signal. By observing the sign of the direction signal at the zero crossing of the speed signal, the direction of rotation of the encoder object can be derived, as illustrated in the following table. Table 1: Zero crossing speed signal CCW clockwise rising Direction signal> 0 Direction signal <0 falling Direction signal <0 Direction signal> 0

This means that, for example, when the speed signal passes a zero-line, ie goes through zero, and thereby increases, the direction signal has values that are greater than zero, in the case of a left-hand rotation and less than zero, in the case of a clockwise rotation of indicator object 150 , Accordingly, the speed signal is falling in the zero crossing, the direction signal is negative in the case of the counterclockwise rotation and positive in the case of the clockwise rotation.

4 thus shows an embodiment of a sensor arrangement 110 to capture from a donor object 150 generated or influenced at least partially periodic magnetic field with a first, second, third and fourth magnetoresistive sensor element 120-1 , ..., 120-4 wherein the first and the second magnetoresistive sensor element 120-1 . 120-2 at a first distance 400 are arranged, wherein the third and the fourth magneto-resistive sensor element 120-3 . 120-4 adjacent at a second distance 410 are arranged, wherein the first and the third magneto-resistive sensor element 120-1 . 120-3 at a third distance 420 are arranged, and wherein the first distance 400 and the second distance 410 less than 50% of the third distance 420 but not less than 1% of the third distance 420 be.

5 shows schematically three courses of signals, as at the two nodes 360-1 . 360-2 of in 4 shown embodiment of a sensor 100-1 or the corresponding sensor arrangement 110-1 can be tapped. More specifically shows 5 a course 430-1 as exemplified at the node 360-1 the two magnetoresistive sensor elements 120-1 . 120-3 can be tapped. According to shows 5 another course 430-2 as he, for example, at the node 360-2 the two sensor elements 120-2 . 120-4 can be tapped. In other words, the course is the same 430-1 the left half bridge, during the course 430-2 the right half bridge corresponds to how they are in 4 are shown.

In addition, between the progressions 430-1 . 430-2 an averaged course 440 which, for example, could correspond to a course, as it is based on a summation of the two courses 430-1 . 430-2 , So as he the sum signal of the evaluation circuit 250 could correspond. The average course 440 Here, for the sake of simplicity, the same signal amplitude is shown as the two outer courses 430-1 . 430-2 , In other words, at the in 5 shown representation of the averaged course 440 neglected that the corresponding sum signal of the evaluation circuit 350 would have a signal amplitude which is about twice as large as the individual signal amplitudes of the two half-bridge circuits involved.

Regarding the in 5 It should also be noted that, for example, the time in the case of a moving donor object is shown on an abscissa of the representation shown there 150 can be applied. With regard to the ordinate shows 5 an oscillation around a zero point value marked by the abscissa (x-axis). Depending on the concrete implementation of an exemplary embodiment, as described, for example, in US Pat 4 This may require numerical or other consideration of a corresponding offset. Of course, a corresponding zero offset shift can also be realized by circuitry, for example, the evaluation circuit 350 a in 4 not shown reference signal of a reference bridge or a voltage Stel ler is provided. Such a voltage divider can be produced, for example, from poly-silicon resistor elements and / or from metallic resistor tracks. Alternatively or additionally, of course, the supply line 380 a, based on a reference potential, negative potential to be impressed, the magnitude of the potential of the supply line 370 equivalent. In one case and one symmetrical design of the magnetoresistive sensor elements 120 the two in 4 provided semiconductor bridge circuits are provided, a corresponding signal can thus be generated even without the implementation of a voltage divider or a reference bridge, the periodic oscillation around a zero value, in response to a movement of the encoder object 150 performs.

In addition, it should be pointed out that in principle it is also possible to realize a corresponding zero point consideration by the use of a full bridge circuit. For this purpose is in the 6a and 6b a comparison of a half-bridge circuit ( 6a ) and a full bridge circuit ( 6b ).

6a already showing in 4 shown series connection of the magnetoresistive sensor elements 120-1 and 120-3 via the center tap or node 360-1 , In contrast to this, in the case of 6b shown full bridge circuit of the previously described half-bridge circuit with the magnetoresistive sensor elements 120-1 . 120-3 and the node 360-1 a further half-bridge circuit with the sensor elements 120'-3 and 120'-1 and the intervening node or center tap 360'-1 connected in parallel. The magnetoresistive sensor elements 120'-1 . 120'-3 can in this case, for example, by doubling the corresponding magnetoresistive sensor structure in the region of the respective magnetoresistive sensor elements 120-1 . 120-3 be generated on the substrate or chip.

With regard to their coupling to the supply lines 370 . 380 However, in this case it should be noted that unlike the magnetoresistive sensor element 120-3 the magnetoresistive sensor element 120'-3 with the supply line 370 , So is coupled to a positive supply voltage. Accordingly, the magnetoresistive sensor elements 120'-1 electrically parallel to the magnetoresistive sensor element 120-3 with the supply line 380 coupled for the negative supply voltage (eg ground (GND)).

In addition, it may be useful to point out that in an implementation of a full bridge circuit such as 6b shows and how they are under 8th will be explained in more detail, the nodes 360'-1 and 360 ' if necessary, both with the evaluation circuit 350 can be coupled. In addition, it makes sense to point out at this point that in principle there is also the possibility of individual magnetoresistive sensor elements 120 to be replaced by corresponding polysilicon resistance elements, a metal line or another metal. Of course, in such a case, the appropriately replaced magneto-resistive sensor element could not have a magnetic field-dependent contribution to that at the corresponding node 360 deliverable differential signal or measuring signal.

In addition, the use of a full bridge circuit, as provided in 6b is shown, in addition to the already mentioned compensation of the zero point in the case of an ideal design, the further advantage of increasing the signal amplitude of the relevant signals, since these now differentially from two different nodes 360 . 360 ' can be tapped.

Before, however, in connection with the 7 to 13 further embodiments of sensors 100 and sensor arrangements 110 are explained, it should be noted at this point that in the present patent application, a first component which is (electrically) coupled to a second component, electrically connected directly to this or via another circuit or another component with this in electrical communication can stand. In other words, in the context of the present patent application, two components which are coupled to one another (electrically) are understood as meaning those which are connected to each other either directly with one another or via another circuit or component. For example, in the case of 4 embodiment shown, the two magnetoresistive sensor elements 120-1 . 120-3 indirectly via the junction 360 coupled together. Depending on the specific embodiment, these two magnetoresistive sensor elements with the respective node 360-1 however, be directly electrically connected.

In addition, it should be noted at this point that identical or similar reference numerals are used in the context of the present patent application for objects, structures and components which have the same or similar functional characteristics. Unless explicitly stated otherwise, portions of the description relating to objects, structures, and components having similar like functional characteristics and features may be interchanged. In this way, the description can be shortened precisely in terms of features, properties and other details that this in connection with various embodiments no longer need to be described professionally. In addition, in the following summary reference symbols are used for objects, structures and components that occur identically or in a similar manner in an exemplary embodiment or in a structure in a figure. Unless otherwise stated, the relevant description passages may also be interchanged with regard to such structures, components or objects. Thus, the use of summary reference numerals also serves to provide a more compact and clearer description of the embodiments of the present invention, as unnecessary repetition can be avoided.

7 shows a further embodiment of a sensor 100-1 with an embodiment of a sensor arrangement 110-1 , The sensor arrangement 110 differs from the in 4 not shown, even if in 7 the first distance 400 , the second distance 410 and the third distance 420 are not shown. Also in the context of this embodiment, the individual distances 400 . 410 . 420 with regard to phase differences with respect to the at least partially periodic magnetic field discussed and explained. The statements made above in connection with the 4 shown embodiment can be transferred accordingly.

This in 7 shown embodiment of a sensor 100 differs, however, with regard to the evaluation circuit 350 and with regard to an additional reference bridge 450 acting as a half-bridge circuit of the resistive elements 460-1 and 460-2 which in turn has a node 470 are connected in series. The reference bridge 450 is here between the two supply lines 370 . 380 , which also switches the supply voltages for the magnetoresistive sensor elements 120 of the embodiment of the sensor arrangement 110-1 out 7 supplies. The node 470 the reference bridge 450 in this case represents the center tap of the half-bridge circuit of the two resistor elements 460 and is with the evaluation circuit 350 coupled. The resistance elements 460-1 . 460-2 can be made of poly-silicon, metallic structures or other materials, as explained above, for example. Depending on the specific implementation, for example, an optionally highly doped or doped poly-silicon resistance voltage divider can be implemented in a corresponding chip, which comprises the two resistance elements 460-1 . 460-2 includes. The resistance elements 460 are also referred to as reference elements, which is why they are in 7 are referred to as "Ref".

The evaluation circuit 350 includes a multiplexer 480 , at whose entrances the two nodes 360-1 . 360-2 are connected. The multiplexer 480 thus makes it possible, either one of the two nodes 360 acting as center taps of the half-bridge circuits of the magnetoresistive sensor elements 120 serves with one of the multiplexers 480 downstream analog / digital converter 490 to pair. The multiplexer 480 thus represents a switch that is capable of at least one of the two center taps 360 the magnetoresistive half-bridge circuits with an input of the analog / digital converter 490 to pair. Another input of the analog / digital converter 490 is beyond that with the center tap or node 470 the reference bridge circuit 450 coupled.

The analog / digital converter 490 is via one or more outputs on the one hand with an addition module 500 and a subtraction module 510 coupled to each in the in 7 illustrated embodiment of a sensor 100-1 a digitized and by a reference voltage of the center tap 470 the reference bridge 450 corrected measurement signal of the two half-bridge circuits with magnetoresistive sensor elements 120 from the nodes 360-1 . 360-2 provides.

In other words, it's the addition module 500 for example, capable of providing to the subsequent modules, circuits and components a signal which is a sum of the two at the nodes 360-1 . 360-2 tapped measurement signals of the half-bridge circuits of the embodiment of a sensor arrangement 110-1 based. The subtraction module is corresponding 510 capable and trained to output a corresponding difference of the relevant measurement signals to the subsequent components. Here are the addition module 500 and the subtraction module 510 provided measurement signals by the analog / digital converter 490 digitized and the reference signal of the reference bridge 450 corrected.

The subtraction module 510 is in turn with an output to an integrator 520 coupled, which is able to temporally aufintegrieren the signals provided at its input or its inputs. To the integrator 520 is also a processing circuit 530 for further processing of the incremental direction sensor data (further incremental direction processing) coupled. The processing circuit 530 is then able to provide an output in direction out at a corresponding output. For example, the processing circuit 530 an ab having a sample and hold circuit which is capable and configured to receive at an input the respective sum signal and then to provide at a output a direction signal based on the sum signal, wherein, for example, the evaluation circuit 350 the sample and hold circuit can provide a clock signal when the difference signal of the subtraction module 510 or a signal derived therefrom has, for example, a zero crossing.

The addition module 500 is in turn connected to a minimum / maximum detection circuit 540 and a processing circuit 550 coupled for further processing of the incremental velocity sensor data. While the processing circuit 550 comparable to the processing circuit 530 On the basis of the incoming signals, an output signal relating to the speed (speed out) is the minimum / maximum detection circuit 540 capable of and adapted to the presence of a minimum or a maximum of the respective incoming signal, that is, the sum signal, as determined by the addition module 500 is issued to recognize. The minimum / maximum detection circuit 540 is beyond that with the integrator 520 coupled such that the integrator 520 by one of the minimum / maximum detection circuits 540 signal (reset signal) is reset to zero or to another value when an extreme, ie a minimum or a maximum, is present.

The signal difference between the two phase-shifted individual signals of the two half-bridge circuits with the magnetoresistive sensor elements includes with respect to the sign of the phase shift information about the direction of rotation, as already the two courses 430-1 . 430-2 out 5 in relation to the sum signal 440 or in the averaged signal 440 have shown. However, since the phase offset is smaller compared to a 90 ° phase-shifted signal, the voltage difference between the two bridges is also small. However, since the direction information is determined only twice per period anyway, the phase shift-related difference of the bridge signals can be integrated between two consecutive extreme values. This makes it possible to improve the signal-to-noise ratio and enable reliable direction detection. An embodiment of a sensor 100-1 as he is in 7 As shown, thus enabling directional detection for incremental speed sensors or speed sensors with an increased sampling rate. In addition, a change in direction of rotation entails a previous lowering of the rotational speed, so that the directional information becomes more accurate as a result of the extension of the integration period between two extreme values, the lower the rotational speed.

In other words, in the context of the evaluation circuit 350 the integrator 520 used to the possibly noisy measurement signals of the two half-bridge circuits, as at the two nodes 360 can be tapped, even to integrate, since on average noise components of the two signals can be deleted numerically by the integration. By doing that, the integrator 520 is implemented, so despite the very small compared to 90 ° phase spacing of the two magnetoresistive sensor elements 120-1 . 120-2 respectively. 120-3 . 120-4 even in the case of a strong noise superposition can still allow reliable direction detection.

8th shows a further embodiment of a sensor 100-1 with an embodiment of a sensor arrangement 110-1 and an evaluation circuit 350 , Unlike the in 7 The embodiment shown in FIG 8th shown embodiment of a sensor 100-1 with regard to the sensor arrangement 110-1 essentially in that they now have a first to fourth magnetoresistive sensor element 120-1 to 120-4 but also a fifth to eighth magnetoresistive sensor element 120'-1 to 120'-4 , which together with the first four magnetoresistive sensor elements 120-1 to 120-4 connected to two full bridge circuits, as related to 6b was explained. Accordingly, not only are the nodes 360-1 . 360-2 the two half-bridge circuits with the first four magnetoresistive sensor elements 120-1 to 120-4 in the sensor arrangement 110-1 but rather two more nodes 360'-1 and 360'-2 between the magnetoresistive sensor elements 120'-1 and 120'-3 respectively. 120'-2 and 120'-4 connected. In return, in the context of in 8th shown embodiment of a sensor 100-1 no reference bridge as in the case of 7 implemented.

In this embodiment, too, with regard to 4 made statements regarding the individual distances and their dimensions to each other or to those of the dimension of a sensor object or to those with respect to the phase differences of the periodic magnetic field.

This results in a further difference with regard to the evaluation circuit 350 in terms of the multiplexer 480 and the analog-to-digital converter 490 , This is the multiplexer 480 at the in 8th shown Embodiment with all four nodes 360 of the embodiment of the sensor arrangement 110-1 and the output of the multiplexer 480 is exclusive to the analogue to digital converter 490 coupled. In the 7 shown coupling of the analog / digital converter 490 to the reference bridge 450 is together with the reference bridge 450 at the in 8th shown embodiment omitted. In addition, further changes may possibly result, which may be a consequence of the increased signal level through the use of a full bridge circuit and other implementation-specific details.

In connection with in the 7 and 8th Furthermore, it should be pointed out that in principle an implementation of an analog / digital converter 490 can be omitted. In such a case, the evaluation circuit can also be implemented as a pure analog circuit. Furthermore, the evaluation circuit 350 further analog or digital signal processing stages include, so about a preamplifier stage and / or one or more amplifier stages. However, all of these components are considered optional components.

9 shows a further embodiment of a sensor 100-2 with an embodiment of a sensor arrangement 110-2 and an evaluation circuit 350 ' , More specifically, the embodiment includes a sensor arrangement 110-2 a first magnetoresistive sensor element 120-1 , a second magnetoresistive sensor element 120-1 and a third magnetoresistive sensor element 120-3 , The first magnetoresistive sensor element 120-1 and the second magnetoresistive sensor element 120-2 are in turn to a supply line 370 coupled, which provides a positive supply voltage Vbridge +, the respective magnetoresistive sensor elements. The third magnetoresistive sensor element 120-3 is in turn with the supply line 380 coupled, this provides a negative supply voltage Vbridge-, which may be, for example, a reference potential, so for example ground (GND).

The first and second magnetoresistive sensor elements 120-1 . 120-2 is with a multiplexer 480 Coupled on the input side. The output side is the multiplexer 480 with a node 360 and in turn coupled to the third magnetoresistive sensor element. With the help of the multiplexer 480 So can the first magnetoresistive sensor element 120-1 together with the third magnetoresistive sensor element 120-3 over the node 360 be switched as a center tap to a half-bridge circuit. Analog can be with the multiplexer 480 also the second magnetoresistive sensor element 120-2 with the third magnetoresistive sensor element 120-3 be connected in accordance with a second half-bridge circuit, the in 9 also with the numeral 1 is marked. Accordingly, the previously described half-bridge circuit with the numeral 2 in 9 characterized.

The multiplexer 480 here, as in 9 is shown, on the one hand as the actual sensor arrangement 110-2 be executed or part of the evaluation 250 ' be. In this case, the individual magnetoresistive sensor elements would be 120 not over the node 360 with the evaluation circuit 350 ' but rather with their respective not connected to the supply line 370 or 380 coupled connections. However, in terms of functionality, functionality, and other parameters, these implementation - specific details have no further impact on the 9 shown embodiment.

As already mentioned in connection with in 4 shown embodiments of a sensor 100-1 was also illustrated at the in 9 shown illustration of the arrow 390 the main detection direction, which is, for example, the x-axis of a coordinate system of the sensor 100-2 or the sensor arrangement 110-2 can act. Likewise, as in 4 , leaves the arrangement of the individual magnetoresistive sensor elements 120 with respect to a direction perpendicular to the main detection direction 390 shown direction in 9 no conclusion on their geometric arrangement on the substrate or the chip of the relevant sensor 100-2 to. This arrangement is essentially aimed at a clear and simple presentation of the relevant embodiments.

The first magnetoresistive sensor element 120-1 and the second magnetoresistive sensor element 120-2 are again at a first distance 400 arranged, based on the periodic magnetic field and the main detection direction 390 a phase difference of at least 1 ° and less than 90 °. Depending on the concrete implementation, this can be done previously in connection with the 4 to 8th explained alternative phase differences are implemented. Similarly, in this context, the context of the alternative definition of further distance made in relation to the statement in 4 referenced embodiment shown.

The second and the third magnetoresistive sensor element 120-2 . 120-3 are also at a further distance, the second distance 560 arranged, which corresponds to a smallest absolute phase difference of at least 110 °. Depending on the concrete implementation of a corresponding embodiment of a sensor 100-2 can the second distance 560 also correspond to a minimum absolute phase difference of at least 25 °, 40 °, 80 °, 110 °, 120 °, 150 ° or at least 170 °.

With regard to a definition of the first distance 400 relative to the second distance 560 Thus, for example, a ratio of the first distance 400 to the second distance 560 be defined to be less than 50%, less than 40%, less than 25%, less than 15% or less than 10%, but not less than 1%, 2% or 5%.

At the in 9 shown embodiment of a sensor 100-2 thus takes place through the multiplexer 180 not a switching back and forth between different, separate half-bridge circuits, as in the context of in the 4 . 7 and 8th shown embodiments of corresponding sensors 100-1 the case was, but within the scope of an embodiment of a sensor 100-2 or the associated sensor arrangement 110-2 , If individual magnetoresistive sensor elements connected to new sensor bridges or half bridges.

In addition, the embodiments of a sensor differ 100-2 from those of a sensor 100-1 with regard to the evaluation circuit 350 respectively. 350 ' barely. Only in terms of the exact arrangement of the multiplexer 480 and the consequent exact position of the node 360 distinguish the evaluation circuits 350 respectively. 350 ' as not least related to the in 10 shown embodiment of an embodiment of a sensor 100-2 will be explained.

Thus, also in the in 9 shown embodiment of a sensor 100-2 through the interconnections of the first magnetoresistive sensor element 120-1 with the third magnetoresistive sensor element 120-3 or the interconnection of the second with the third magnetoresistive sensor element 120-2 . 120-3 a virtual magnetoresistive sensor element between the positions of the first and second magnetoresistive sensor elements 120-1 . 120-2 created, which virtually over the node 360 with the third magnetoresistive sensor element 120-3 is connected to a half-bridge circuit. Thus, a distance of this virtual magnetoresistive sensor element corresponds to the third magneto-resistive sensor element 120-3 about one in 9 drawn distance 570 which in some embodiments correspond to a phase difference of about 180 °.

Here, phase differences φ correspond to a period λ of the encoder object 150 , also referred to as a period, a distance D that can be converted into each other according to the following equation: φ / 360 ° = D / λ (3)

So it is For example, the period 2.5 mm, so of course corresponds to one Distance D = 2.5 mm a phase difference of 360 °. Analogous A phase difference of 90 ° corresponds to a distance of about 0.625 mm and a phase difference of 180 ° a length or distance of 1.25 mm.

9 thus shows an embodiment of a sensor arrangement 100-2 to capture one from a donor object 150 generated or influenced at least partially periodic magnetic field with a first, second and third magnetoresistive sensor element 120-1 . 120-2 . 120-3 wherein the first and second magneto-resistive sensor elements are adjacent to a first distance 400 are arranged, wherein that second and third magnetoresistive sensor element 120 at a second distance 560 and wherein the first distance is less than 50% of the second distance 560 but not less than 1% of the second distance 560 is.

10 shows a further embodiment of a sensor 100-2 with an embodiment of a sensor arrangement 110-2 , This in 10 shown embodiment 100-2 differs, apart from the more detailed description of a possible implementation of an evaluation circuit 350 ' in essence, that in contrast to the in 9 embodiment shown in FIG 10 again shown embodiment based on a full bridge circuit. Thus, the sensor arrangement comprises 110-2 in addition to the aforementioned three magnetoresistive sensor elements 120-1 . 120-2 and 120-3 in its previously explained arrangement also a fourth magnetoresistive sensor element 120'-1 , a fifth magnetoresistive sensor element 120'-2 and a sixth magnetoresistive sensor element 120'-3 . via another multiplexer 480 ' and another node 260 ' in a substantially to the circuit of the first three magnetoresistive sensor elements 120 mirrored circuit are interconnected. Here are the fourth and the fifth magnetoresistive sensor element 120'-1 . 120'-2 also in the first distance or the first distance 400 arranged, wherein the fifth and the sixth magnetoresistive sensor element 120'-2 . 120'-3 also in the further or in the second distance 560 are arranged.

This makes it within the scope of an embodiment of a sensor 100-2 it is possible to switch back and forth between (at least) two full-bridge configurations by respectively the first and fourth magnetoresistive sensor elements 120-1 . 120'-1 as a sensor bridge configuration 2 or the second magnetoresistive sensor element 120-2 and the fifth magneto-resistive sensor element 120'-2 are interconnected as the first sensor bridge configuration accordingly.

With regard to the evaluation circuit 350 ' this differs from the example in 8th shown evaluation circuit 350 essentially by the fact that the multiplexer 480 out 8th in the form of two multiplexers 480 . 480 ' in the context of the sensor arrangement 110-2 can be implemented. As a result, the nodes 360 . 360 ' directly with the analog-to-digital converter 490 coupled. In addition, however, the evaluation circuits differ 350 . 350 ' from the 8th and 10 basically not.

As already related to 9 may be explained in an alternative implementation of an embodiment of a sensor 100-2 the implementation of the multiplexers 480 . 480 ' also in the form of, for example, a single or multiple multiplexers in the context of the evaluation circuit 250 ' be made. In this case, it may be advisable to use all six magnetoresistive sensor elements 120 directly with the evaluation circuit 350 ' to couple, in each case one terminal of the magnetoresistive sensor elements 120 with one of the supply lines 370 . 380 is coupled.

In addition, this differs in 10 However, for example, also with regard to the geometric arrangement of the individual magnetoresistive sensor elements not shown in the embodiment shown 9 shown. For this reason, the corresponding description with regard to the geometric arrangement of the individual sensor elements is previously referred to at this point. Also with regard to the different definitions of the individual distances to each other is related to the statements 4 and 9 directed.

11 shows a further embodiment of a sensor 100-3 in which one embodiment for the differential measurement and acquisition of two 90 ° phase shifted signals described above.

The embodiment of a sensor 100-3 thus comprises a first magnetoresistive sensor element 120-1 , a second magnetoresistive sensor element 120-2 that have a node 360-1 in series between a supply line 370 for a positive supply voltage and a supply line 380 for a negative supply voltage, for example, a reference potential (ground (GND)) are connected. The first magnetoresistive sensor element and the second magnetoresistive sensor element 120-1 . 120-2 thus form a half-bridge circuit with a center tap 360-1 , Analogously, the embodiment includes a sensor 100-3 or the sensor arrangement 110-3 a third magnetoresistive sensor element 120-3 and a fourth magnetoresistive sensor element 120-4 that have another node 360-2 connected in series with each other. As well as the first and the second magnetoresistive sensor element 120-1 . 120-2 These two magnetoresistive sensor elements also form a half-bridge circuit, which is located between the supply lines 370 and 380 is switched.

As also previously in connection with the embodiments in the 4 and 9 has been described, here are the individual magnetoresistive sensor elements 120 , relative to the main detection direction 390 of the sensor 100-3 , So for example, based on an x-coordinate, spatially distributed accordingly. Perpendicular to this, the corresponding representation is again shown for the simplified representation of the relevant circuit. Here, in the context of the present application under a main detection direction 390 such understood, for example, a direction of rotation of a donor object 150 describes above or below the sensor.

The first and the second magnetoresistive sensor element 120-1 . 120-2 are here at a first distance 580 arranged, the one smallest absolute phase difference, based on the periodic magnetic field, the corresponding sensor, for example by the encoder object 150 may be exposed, corresponding to at least 20 °. The second and the third magnetoresistive sensor element 120-2 . 120-3 are however, at a second distance 590 arranged corresponding to a minimum absolute phase difference, based on the periodic magnetic field of at most 40 °. The third magnetoresistive sensor element and the fourth magnetoresistive sensor element 120-3 . 120-4 beyond that are at a third distance 600 arranged as well as the first distance 580 a minimum absolute phase difference, referred to the periodic magnetic field, of at least 20 °.

In further embodiments of a corresponding sensor 100-3 may be the first distance 580 and the third distance 600 corresponding to a minimum absolute phase difference with respect to the periodic magnetic field of at least 30 °, 40 °, 60 ° or at least 80 °. Accordingly, in other embodiments, the second distance 590 correspond to a minimum absolute phase difference of less than 30 °, 20 °, 10 °, 5 °, 2 ° or less than 1 °. Under optimal conditions, the first distance corresponds 580 and the third distance 600 each having a minimum absolute phase difference with respect to the periodic magnetic field and the main sense direction 390 from about 90 ° (+/- 1 ° or +/- 2 °). In addition, in this case corresponds to the second distance 590 a minimum absolute phase difference of less than 1 °, 2 ° or 5 °.

Also in the context of an embodiment of a sensor 100-3 the statements made above regarding the relationship of the individual distances to each other, as they relate to 4 were explained in more detail. So in this case, for example, the second distance 590 depending on the first distance 580 or depending on the third distance 600 To be defined. Likewise, the third distance 600 depending on the first distance 580 To be defined. Depending on the circumstances, for example, the third distance 600 based on the first distance 580 in a range between 50% of the first distance and 200% of the first distance 580 lie. Accordingly, for example, the third distance 600 in terms of the first distance 580 even in a range between 80% and 120% of the first distance 580 or in a range between 90% and 110% of the first distance 580 lie. With regard to the second distance 590 this can be related to the first distance 580 in different embodiments are less than 50%, 30%, 20%, 10% or 5%.

Further, in this embodiment, the individual magnetoresistive sensor elements are arranged in parallel on a line, for example a straight line. In addition, in various embodiments of a corresponding sensor 100-3 the magnetoresistive sensor elements 120 have a common preferred direction with respect to the detection of magnetic fields. Depending on the specific technological design of the magnetoresistive sensor elements 120 For example, they may be conditioned with respect to a common direction.

In addition, the embodiment of a sensor 100-3 an evaluation circuit 350 '' on, with the two nodes or center taps 360-1 . 360-2 the interconnected to two half-bridges magnetoresistive sensor elements 120 is coupled. Depending on the concrete implementation, the relevant measurement signals of the two nodes can be used here 360-1 . 360-2 one or more optional preprocessing circuits 610 For example, they may perform preamplification, filtering, and / or analog-to-digital conversion.

The possibly implemented preprocessing circuit 160 following are then in the evaluation circuit 350 '' one addition module each 620 and a subtraction module 630 downstream, with both the addition module 620 as well as the subtraction module 630 in each case the possibly preprocessing signals of the two nodes 360-1 . 360-2 to provide. The addition module 620 In this case, it is able and designed to form a summation signal based on the optional preprocessing measurement signals made available to it, which has information relating to a speed of the encoder object. This may be, for example, a frequency of the signal in question Sig, a slope or other corresponding information. The subtraction module 630 In contrast to this, it is able and designed to generate a difference on the basis of the optionally preprocessed measuring signals provided for this purpose, which in turn has information relating to a direction of the encoder object 150 which is responsible for the modulation, more specifically, the periodic modulation of the magnetic field, which is the embodiment of the sensor 100-3 is exposed.

Both the addition module 620 as well as the subtraction module 630 each have an output, possibly with an output of the evaluation circuit 350 '' and, where applicable, the relevant information in the form of further signals in the context of a 11 Not shown post-processing can be extracted.

In this connection, it should be mentioned that not only half-bridge circuits can be used in accordance with the exemplary embodiments explained above in the context of the present application, but also a full-bridge circuit or a plurality of full-bridge circuits within the scope of an exemplary embodiment of a sensor arrangement can be achieved by doubling the respective magnetoresistive sensor elements 110-3 be implemented.

11 thus shows an embodiment of a sensor 100-3 to capture one from a donor object 150 generated or influenced at least partially periodic magnetic field with a first, second, third and fourth magnetoresistive sensor element 120-1 , ..., 120-4 wherein the first and the second magnetoresistive sensor element 120-1 . 120-2 at a first distance 580 are arranged, wherein the second and the third magneto-resistive sensor element 120-2 . 120-3 at a second distance 590 are arranged, wherein the third and the fourth magneto-resistive sensor element 120-3 . 120-4 are arranged at a third distance, and the fer ner an evaluation circuit 350 configured to be based on a first difference signal of the first and the second magnetoresistive sensor element 120-1 . 120-2 and based on a second difference signal of the third and fourth sensor elements 120-3 . 120-4 to provide a sum signal and a difference signal, the sum signal having information regarding a speed of the encoder object 150 and wherein the difference signal information with respect to a direction of the encoder object 150 having.

Before under the 12 and 13 It should be noted that in the following the measurement signals or resistance values of the four magneto-resistive sensor elements are described in more detail with reference to different signal waveforms and evaluation signal courses, for example the previously explained difference signal and the previously explained sum signal 120 out 11 be denoted by the names B1, B2 and B3. This is for the measurement signals or resistance values of the two magnetoresistive sensor elements 120-2 and 120-3 the common designation B2 is used, as this, as previously explained, in the second distance 590 are arranged, based on the main detection direction 390 and the periodic magnetic field generated or influenced by the encoder object corresponds to a phase difference of at most 10 °. For this reason, the measuring signals of the second and the third magnetoresistive sensor element can to a good approximation 120-2 . 120-3 be described by a corresponding measurement signal or its identifier B2.

As will be explained below, it enables one embodiment of a sensor 100-3 To implement a method that allows a Drillrichtungserkennung whose signal to noise ratio is significantly improved over external interference fields. So shows 12 two waveforms of signals in arbitrary units as a function of time t, as explained before, about a rotational speed or another velocity v of the encoder object 150 corresponds to a corresponding coordinate, for example an x-coordinate. More precisely, is in 12 on the one hand, a course 640 of the second magnetoresistive sensor 120-2 or the third magnetoresistive sensor 120-3 , So reproduce the signal B2, which is assumed for simplicity that it is sinusoidal or cosinus-shaped signal. In addition, in 12 also as a course 650 a course of a difference signal of the individual signals B3 (of element 120-1 ) and the single signal B1 (of the element 120-4 ). This has a phase difference to the course due to the conditions described above 640 on, which may for example be at 90 °.

In other words, are in 12 the signals for the optimal case shown that the distance between the two outer sensors corresponds to half a tooth period. The tooth period or the pitch here is the sum of tooth width and gap width and it is further assumed here that the tooth width and the gap width are identical. In this case, the signal B3-B1, which can also be drawn as a speed signal (speed signal), is maximally large, namely twice as large as the direction signal (Direction Signal), which can correspond, for example, to the measurement signal B2. Conversely, the direction signal is typically only half the speed signal.

If the air gap, so the distance of the sensor 110 to the gear or the encoder object 150 becomes large, the fields become exponentially smaller, so that eventually the direction signal is now so small that external interference can have a significant impact on the detection. Optionally, the signal B2 can now be based on a flux density of approximately 1 mT. In such a case, even a small interference from the outside at the moment of a zero crossing of the speed signal can cause the relevant direction signal, for example, to assume a false sign, which may possibly lead to erroneous direction detection. An embodiment of a sensor 100-3 as it is in 11 Rather, a robust recognition and detection of a directional signal can be achieved by using a gradiometer circuit, so that in this case a measurement identifier may be replaced by the Use of an embodiment can be improved.

In the context of the corresponding embodiment of a sensor 100-3 Can basically use only 4 magnetoresistive sensor elements, like this 11 also shows a very robust direction detection can be implemented, so that no additional sensor or no additional sensor element is needed. Of course, a plurality of additional sensor elements can be used to execute, for example, a corresponding detection in the context of a full bridge circuit.

Rather, the four, in 11 shown magnetoresistive sensor elements 120 operated in several Gradiometeranordnungen, ie in the form of circuits in which a difference signal is determined based on spatially separated individual signals. In the case of in 11 This is realized, for example, by the use of two half-bridge circuits, in which the two magnetoresistive sensor elements 120 , which are involved in a half-bridge circuit, at a corresponding distance, so the first or third distance 580 . 600 are arranged.

Will the four magnetoresistive sensors 120 numbered 1, 2 and 3 starting from the left, the second magnetoresistive sensor and the third magnetoresistive sensor, as explained above, being regarded as a signal generator for the signal B2, a speed signal can be obtained, for example, on the basis of the signals B3-B1 , In addition, a difference Dir1 = B1-B2 and Dir2 = B2-B3 can be defined as a directional signal.

Due to the subtraction subtracted by the bridge circuit, the two signals Dir1 and Dir2 have now become insensitive to homogeneous disturbances as differential signals. So become the two signals Dir1 and Dir2, those at the nodes 360 can be tapped directly, through the bridge circuits of the individual sensors 120 and possibly subsequently only in the context of the preprocessing circuits 610 strengthened.

As a result, a large dc field, such as a homogeneous magnetic field, which affects the entire sensor 100-3 acts, no longer to an override of possibly in a preprocessing circuit 610 implemented preamplifier leads. In addition, small high-frequency superimposed DC fields, so-called spikes, which are frequently encountered, for example when starting a motor, by the implicit subtraction in the bridge circuits before reaching the preprocessing circuit 610 be eliminated.

In other words, these no longer run through an existing preamplifier, so that it must be made less broadband, since the signals in question in such a case no longer need to be completely transferred. This results in additional advantages with regard to an implementation of such an amplifier, since the signals should now be transmitted without distortion in a smaller frequency band. Thus, an influence of different zero-point values (offset) or different linearities of the preamplifier circuits in the context of the preprocessing circuit 610 can be implemented because corresponding signals no longer or to a good approximation, the preprocessing circuit 610 not reach anymore.

The preamplifier or amplifier can So be implemented with a lower bandwidth, on the one hand a reduction of the chip area and on the other hand a reduction of electricity and energy consumption can realize. About that In addition, it may depend on come from the concrete implementation of an embodiment to that due to the narrowband preamplifier a useful signal, if necessary less noise superimposed becomes. About that can out also non-homogeneous interference fields affect a measurement result or the measuring signals less strongly, because the corresponding preprocessing circuits in this case can be designed with a lower bandwidth or not even incurred.

In the case of digital signal processing, that is, for example, an analog / digital converter as part of a preprocessing circuit 610 In addition, a reduction of aliasing errors that can occur as a result of high-frequency interference in conjunction with a predetermined sampling rate in the context of the analog / digital conversion can also occur. In other words, embodiments of a sensor 100-3 have the additional advantage that in the case of digital billing of the signals high-frequency homogeneous shares can be better calculated.

Embodiments of a sensor 100-3 Moreover, additionally have the advantage that by the separation of the central sensors, ie by introducing the second magnetoresistive sensor 120-2 and a third magnetoresistive sensor element separated therefrom 120-3 a splitting of the measurement setup in two galvanically isolated half-bridge circuits is possible, so that a mutual interference of the two half-bridges or the infrastructure connected to it can be reduced.

In other words, depending on the specific implementation of an exemplary embodiment, a great variety of advantages can result, in that the computation or difference formation of the respective measurement signals is shifted to the bridge circuit, so that a corresponding summation no longer has to be explicitly implemented. The individual signals of the individual magnetoresistive sensor elements 120 Therefore, depending on the corresponding implementation of a sensor 100-3 not in the context of the evaluation circuit 350 '' , be performed.

Thus arise in the in 11 illustrated embodiment of a sensor 100-3 the following, in 13 shown waveforms in arbitrary units (w. E.), in turn, the gradients shown there are based on the case that the distance between the two outer sensors 120-1 . 120-4 half the period length of the gear (pitch) corresponds.

13 illustrates a directional detection with purely differential signals. More precisely, shows 13 four courses 660 . 670 . 680 and 690 , where the course 660 corresponds to the signal Dir1 = B1 - B2. Accordingly, the course relates 670 to the Dir2 signal, so the signal B2 - B3. A speed signal (speed signal) is also in 13 as a course 680 drawn, which is the sum of the two signals Dir1 and Dir2, so as a sum signal at an output of the addition module 620 results. Finally, in 13 the history 690 is drawn, which corresponds to a direction signal Dir = Dir2 - Dir1 = 2B2 - B1 - B3.

13 thus shows a further advantage, which in the case of various embodiments of a sensor 100-3 can result. So now are the amplitudes of the signals Dir1 and Dir2, those at the nodes 360 can be tapped to detect with an amplitude about 41% greater than a comparable signal B2. This results in an assignment of the signals to the direction of rotation according to the following table: TABLE 2 Zero crossing speed signal CCW clockwise rising Dir1 signal> 0 Dir1 signal <0 falling Dir1 signal <0 Dir1 signal> 0

Alternatively, this may also be expressed in terms of the Dir2 signal. This results in the following table: TABLE 3 Zero crossing speed signal CCW clockwise rising Dir2 signal <0 Dir2 signal> 0 falling Dir2 signal> 0 Dir2 signal <0

Taken together, Thus, the following relationship results in the case of zero crossing of the speed signal or

Speed signal according to the following table: Table 4: Zero-crossing CCW clockwise Speed signal rising Dir1 signal> Dir2- Dir1 signal <Dir2- signal signal falling Dir1 signal <Dir2- Dir1 signal> Dir2- signal signal

Although, in principle, it is basically possible to carry out a direction detection on the basis of the Dir1 signal or the Dir2 signal, use of the previously explained direction signal Dir based on both signals, ie the first difference signal Dir1 and the second difference signal Dir2, if necessary . the advantage of a significantly increased noise immunity. This is because, if it comes to strong disturbances, the z. B. the magnetoresistive sensor elements 120 (xMR elements) near saturation or the amplifying electronics of the preprocessing circuit 610 Although the first difference signal Dir1 or the second difference signal Dir2 may influence this somewhat, the distance of the two difference signals Dir1 and Dir2 is in many cases even more robust against such concurrent disturbances. Both direction signals or both difference signals are spaced twice as far in the zero crossing of the speed signal, such as a single signal B2.

By subtracting the two differential signals Dir1 and Dir2 again from one another, one can thus obtain a direction signal Dir = Dir2-Dir1 = 2B2-B1-B3, as this is the course 690 in 13 is registered. This signal or this course now has the same amplitude as the speed signal (speed signal) of the course 680 and the following relationships apply: TABLE 5 Zero crossing speed signal CCW clockwise rising Dir signal <0 Dir signal> 0 falling Dir signal> 0 Dir signal <0

These relationships correspond in principle to those of a single centrally arranged sensor element, except that due to the interconnection now a double signal amplitude can result under ideal conditions. Of course, it should be noted that corresponding relations also by a changed interconnection or a modified installation of the sensor with respect to the encoder object 150 can be realized, so that if necessary apply correspondingly changed relations for the individual waveforms.

Here lies the in 13 shown courses 660 to 690 based on the following mathematical relations B1 = B 0 · Cos (2π · (x - dx) / p) = B 0 · Cos (2π · (v · t - dx) / p) (4) B2 = B 0 · Cos (2π · / p) = B 0 · Cos (2π · v · t / p) (5) B3 = B 0 · Cos (2π (x + dx) / p) = B 0 · Cos (2π (vt + dx) / p) (6)

Here, B ₀ gives an amplitude of the magnetic field, x the distance relative to the circumference of the gear as a donor object 150 , dx the distance between the middle sensor and the middle sensors 120-2 and 120-3 and the right and left sensors 120-1 . 120-4 at. In addition, p is the period or the pitch of the gear or the encoder object 150 ,

Thus, in this case for the speed signal or the speed signal: B3 - B1 = 2B 0 · Sin (2π vt / p) · sin (2π dx / p) (7)

For the Dir1 signal applies accordingly Dir1 = B1 - B2 = 2 · B 0 · Sin (π · dx / p) · sin (2π · (v · t - dx / 2) / p) (8) and for the Dir2 signal dir2 = B2 - B3 = 2B 0 sin (π * dx / p) * sin (2π * (vt + dx / 2) / p). (9)

Thus, the following equation follows for the total signal or difference signal Dir: dir = dir1 - dir2 = 2B2 - B1 - B3 = 4B 0 · Cos (2π vt / p) · sin 2 (π · dx / p) (10)

So is the difference signal, Dir signal or direction signal by 90 ° to the Speed signal independent shifted from the gear period. Thus, the direction signal each sampled in a maximum or minimum, if the Speed signal (speed signal) has a zero crossing.

As previously explained, the speed signal is identical to the sum of the two differential signals Dir1 and Dir2, as it is at the nodes 360 can be tapped. This makes it possible to construct a very economical circuit, as it does as an exemplary embodiment of a chip 100-3 in 11 is shown by way of example. It will only be the two at the nodes 360-1 . 360-2 tapped Dir1, Dir2 amplified and possibly further preprocessed, as in the context of a possible implementation of the preprocessing circuits 610 was explained. This can then be determined by an addition in the context of the addition module 620 the speed signal (speed signal) and by subtraction in the subtraction module 630 win the direction signal (Dir signal). Depending on the specific implementation, it is of course also possible to obtain further signals or signals based on the speed signal and / or the direction signal. Compared to a simple evaluation of the signals B3 - B1 and B2, this corresponds to a not significantly increased effort, since these signals are possibly also subjected to a corresponding preprocessing or preprocessing.

An embodiment of a sensor 100-3 as it is in 11 Thus, the advantage is shown that all signals are obtained from differential "fields" or difference signals and thus are substantially immune to homogeneous background fields or interference fields 100-3 the direction signal is now detected with a comparable or equal amplitude as the speed signal, so that even with larger air gaps between the sensor and the encoder object direction detection can still be done reliably. In particular, by the use of the two magnetoresistive sensor elements 120-2 . 120-3 can thus by using two half-bridge circuits from the sensor elements 120-1 . 120-2 such as 120-3 and 120-4 the two difference signals Dir1 and Dir2 are obtained with similar bridges.

An embodiment of a sensor 100-3 as he is in 11 Thus, a direction signal based on two differential signals achieved by interconnection of a gradiometer of the four in 11 shown magnetoresistive sensor elements 120 , whereby a much more robust sensor arrangement can be achieved against superimposed interference magnetic fields. If, as described, both direction signals are used for direction detection, the signal-to-noise ratio doubles compared to a simple use of a single sensor element. Depending on the exact implementation of an embodiment of a chip 100 Thus, a more robust direction detection or direction detection for incremental speed sensors (speed sensors) can be achieved if necessary using an increased sampling rate.

Depending on the circumstances, an embodiment of a method according to the invention can be implemented in hardware or in software. The implementation can be carried out on a digital storage medium, in particular a floppy disk, CD or DVD with electronically readable control signals, which can cooperate with a programmable computer system so that an embodiment of a method according to the invention is carried out. In general, an exemplary embodiment of the invention therefore also consists of a software program product or a computer program product or a program product with a program code stored on a machine-readable carrier for carrying out an exemplary embodiment of a method according to the invention, if the Software program product runs on a computer or a processor. In other words, an embodiment of the present invention can thus be described as a computer program or a software program or program with a program code for carrying out an embodiment of the method be realized when the program runs on a processor. The processor can in this case be formed by a computer, a smart card, a sensor, an application-specific integrated circuit (ASIC) or another integrated circuit (IC = Integrated Circuit).

100

sensor

110

sensor arrangement

120

magnetoresistive sensor element

130

Back-bias magnet

140

housing

150

indicator object

160

magnetic Area

170

field lines

180

position

190

sensor module

200

engine

210

Index gap

220

motor housing

230

piston

240

connecting rod

250

cylinder head

260

inlet channel

270

exhaust port

280

Valve

290

combustion chamber

300

spark plug

310

injection

320

Coolant channel

330

Coolant temperature sensor

350

evaluation

360

junction

370

supply line

380

supply line

390

Main detection direction

400

first distance

410

second distance

420

third distance

430

course

440

averaged course

450

reference bridge

460

resistive element

470

junction

480

multiplexer

490

Analog / digital converter

500

addition module

510

subtraction

520

integrator

530

Prozessierungsschaltung

540

Minimum / maximum detection circuit

550

Prozessierungsschaltung

560

second distance

570

distance

580

first distance

590

second distance

600

third distance

610

preprocessing

620

addition module

630

subtraction

640

course

650

course

660

course

670

course

680

course

690

course

Claims (54)

Sensor arrangement ( 110 ) for capturing one of a donor object ( 150 ) generated or influenced at least sections of periodic magnetic field, with the following features: a first, second, third and fourth magnetoresistive sensor element ( 120 ), wherein the first and the second magnetoresistive sensor element ( 120 ) adjacent at a first distance ( 400 ) are arranged; wherein the third and the fourth magnetoresistive sensor element ( 120 ) adjacent at a second distance ( 410 ) are arranged; wherein the first and third magnetoresistive sensor elements ( 120 ) at a third distance ( 420 ) are arranged; where the first distance ( 400 ) and the second distance ( 410 ) correspond to a minimum absolute phase difference with respect to the periodic magnetic field of at least 1 ° and less than 90 °; and wherein the third distance ( 440 ) corresponds to a minimum absolute phase difference of at least 25 °. Sensor arrangement ( 110 ) according to claim 1, wherein the first, second, third and fourth magnetoresistive sensor elements ( 120 ) parallel on a line with respect to a main detection direction ( 390 ) of the sensor arrangement ( 110 ) are arranged. Sensor arrangement ( 110 ) according to one of the preceding claims, in which the first, second, third and fourth magnetoresistive sensor elements ( 120 ) have a common preferred direction for detecting a magnetic field. Sensor arrangement ( 110 ) according to one of the preceding claims, in which the first, second, third and fourth magnetoresistive sensor elements ( 120 ) have conditioning with respect to a common direction. Sensor arrangement ( 110 ) according to one of the preceding claims, in which the sensor arrangement further comprises an evaluation circuit ( 350 ) configured to determine, based on a first difference signal of the first and third magnetoresistive sensor elements ( 120 ) and based on a second difference signal of the second and the fourth magnetoresistive sensor element ( 120 ) provide a sum signal and a difference signal, wherein the sum signal information with respect to a speed of the encoder object ( 150 ), wherein the difference signal information with respect to a direction of the speed of the encoder object ( 150 ) having. Sensor arrangement according to Claim 5, in which the evaluation circuit ( 350 ) an integrator ( 520 ), which is configured to aufintegrieren the difference signal, and in which the evaluation circuit ( 350 ) is further configured so that the integrated difference signal information with respect to the direction of the speed of the encoder object ( 190 ) having. Sensor arrangement ( 110 ) according to claim 6, wherein the evaluation circuit further comprises a minimum / maximum detector ( 540 ) which is connected to the integrator ( 520 ) is configured and configured in such a way that, in the presence of a maximum or a minimum of the sum signal, the integrator ( 520 ) reset. Sensor arrangement ( 110 ) according to one of claims 5 to 7, in which the evaluation circuit ( 350 ) an analog / digital converter ( 490 ) and in which the evaluation circuit ( 350 ) is further configured to digitally process and / or provide the first difference signal, the second difference signal, the sum signal and the difference signal. Sensor arrangement ( 110 ) according to one of the preceding claims, in which the first and the third magnetoresistive sensor element ( 120 ) in series with a half-bridge circuit having a center tap ( 360 ) between the first and the third magnetoresistive sensor element ( 120 ) and in which the second and the fourth magnetoresistive sensor element ( 120 ) as a series connection to a further half-bridge circuit with a center tap ( 360 ) between the second and the fourth magnetoresistive sensor element ( 120 ) are coupled. Sensor arrangement ( 110 ) according to one of the preceding claims, in which the first distance ( 400 ) and the second distance ( 410 ) is less than 20% of the first distance ( 400 ). Sensor arrangement ( 110 ) according to one of claims 5 to 10, further comprising a fifth, sixth, seventh and eighth magnetoresistive sensor element ( 120 ), wherein the fifth and the sixth magnetoresistive sensor element ( 120 ) at the first distance ( 400 ), wherein the seventh and the eighth magnetoresistive sensor element ( 120 ) in the second distance ( 410 ), wherein the fifth and the seventh magnetoresistive sensor element ( 120 ) in the third distance ( 420 ) are arranged, and wherein the evaluation circuit ( 350 ) is further configured to provide the difference signal and the sum signal based on the first difference signal and the second difference signal, the first difference signal on the first, third, fifth and seventh sensor elements ( 120 ), and wherein the second difference signal on the second, fourth, sixth and eighth magnetoresistive sensor element ( 120 ). Sensor arrangement ( 110 ) according to claim 11, wherein the first and the fifth magnetoresistive sensor element ( 120 ) at a fourth distance relative to a main detection direction ( 390 ) of the sensor arrangement ( 110 ), wherein the fourth distance is less than or equal to the first distance ( 400 ). Sensor arrangement ( 110 ) according to one of claims 11 or 12, in which the fifth and the seventh magnetoresistive sensor element ( 120 ) as a series connection to a half-bridge circuit with a center tap ( 360 ) and wherein the sixth and the eighth magnetoresistive sensor element ( 120 ) as a series connection to a half-bridge circuit with a center tap ( 360 ) are coupled. Sensor arrangement ( 110 ) for capturing one of a donor object ( 150 ) generated or influenced at least sections of periodic magnetic field, with the following features: a first, second and third magnetoresistive sensor element ( 120 ), wherein the first and the second magnetoresistive sensor element ( 120 ) adjacent at a first distance ( 400 ) are arranged; wherein the second and the third magnetoresistive sensor element ( 120 ) at a second distance ( 560 ) are arranged; where the first distance ( 400 ) correspond to a minimum absolute phase difference with respect to the periodic magnetic field of at least 1 ° and less than 90 °; and wherein the second distance ( 560 ) corresponds to a minimum absolute phase difference of at least 25 °. Sensor arrangement ( 110 ) according to claim 14, wherein the sensor arrangement further comprises an evaluation circuit ( 350 ) configured to determine, based on a first difference signal of the first and third magnetoresistive sensor elements ( 120 ) and based on a second difference signal of the second and the third magnetoresistive sensor element ( 120 ) provide a sum signal and a difference signal, wherein the sum signal information with respect to a speed of the encoder object ( 150 ), wherein the difference signal information with respect to a direction of the speed of the encoder object ( 150 ) having. Sensor arrangement ( 110 ) according to claim 15, in which the evaluation circuit ( 350 ) an integrator ( 520 ), which is configured to aufintegrieren the difference signal, and in which the evaluation circuit ( 350 ) is further configured so that the integrated difference signal information with respect to the direction of the speed of the encoder object ( 150 ) having. Sensor arrangement ( 110 ) according to claim 16, wherein the evaluation circuit further comprises a minimum / maximum detector ( 540 ) which is connected to the integrator ( 520 ) is configured and configured in such a way that, in the presence of a maximum or a minimum of the sum signal, the integrator ( 520 ) reset. Sensor arrangement ( 110 ) according to one of claims 15 to 17, in which the evaluation circuit ( 350 ) an analog / digital converter ( 490 ) and in which the evaluation circuit ( 350 ) is further configured to digitally process and / or provide the first difference signal, the second difference signal, the sum signal and the difference signal. Sensor arrangement ( 110 ) according to one of claims 15 to 18, further comprising a fourth, fifth and sixth magnetoresistive sensor element ( 120 ), wherein the fourth and the fifth magnetoresistive sensor element ( 120 ) at the first distance ( 400 ), wherein the fifth and the sixth magnetoresistive sensor element ( 120 ) in the second distance ( 560 ) are arranged, and wherein the evaluation circuit ( 350 ) is further configured to provide the difference signal and the sum signal based on the first difference signal and the second difference signal, wherein the first difference signal on the first, third, fourth and sixth sensor elements ( 120 ), and wherein the second difference signal on the second, third, fifth and sixth magnetoresistive sensor element ( 120 ). Sensor ( 100 ) for capturing one of a donor object ( 150 ) generated or influenced at least sections of periodic magnetic field, with the following features: a first, second, third and fourth magnetoresistive sensor element ( 120 ); and an evaluation circuit ( 350 ), wherein the first and the second magnetoresistive sensor element ( 120 ) adjacent at a first distance ( 400 ) are arranged; wherein the third and the fourth magnetoresistive sensor element ( 120 ) adjacent at a second distance ( 410 ) are arranged; wherein the first and third magnetoresistive sensor elements ( 120 ) at a third distance ( 420 ) are arranged; where the first distance ( 400 ) and the second distance ( 410 ) correspond to a minimum absolute phase difference with respect to the periodic magnetic field of at least 1 ° and less than 90 °; where the third distance ( 420 ) corresponds to a minimum absolute phase difference of at least 25; wherein the evaluation circuit ( 350 ) is configured to be based on a first difference signal of the first and the third magnetoresistive sensor element ( 120 ) and based on a second difference signal of the second and the fourth magnetoresistive sensor element ( 120 ) provide a sum signal and a difference signal, wherein the evaluation circuit ( 330 ) an integrator ( 520 ) configured to integrate the difference signal; wherein the sum signal information with respect to a speed of the encoder object ( 150 ) having; and wherein the integrated difference signal contains information relating to a direction of the velocity of the encoder object ( 150 ) having. Sensor ( 100 ) according to claim 20, wherein the evaluation circuit ( 350 ) a minimum / maximum detector ( 540 ) which is connected to the integrator ( 520 ) and configured to reset the integrator when a maximum or a minimum of the sum signal is present ( 520 ) to effect. Sensor according to one of claims 20 or 21, further comprising a fifth, sixth, seventh and eighth magnetoresistive sensor element ( 120 ), wherein the fifth and the sixth magnetoresistive sensor element ( 120 ) at the first distance ( 400 ), wherein the seventh and the eighth magnetoresistive sensor element ( 120 ) in the second distance ( 410 ), wherein the fifth and the seventh magnetoresistive sensor element ( 120 ) in the third distance ( 420 ) are arranged, and wherein the evaluation circuit ( 350 ) is further configured to provide the sum signal and the difference signal based on the first difference signal and the second difference signal, wherein the first difference signal on the first, third, fifth, and seventh magnetoresistive sensor elements ( 120 ), and wherein the second difference signal on the second, fourth, sixth and eighth magnetoresistive sensor element ( 120 ). Sensor ( 100 ) according to claim 22, wherein the first and third magnetoresistive sensor elements ( 120 ), the second and the fourth magnetoresistive sensor element ( 120 ), the fifth and the seventh magnetoresistive sensor element ( 120 ) and the sixth and eighth magnetoresistive sensor elements ( 120 ) in each case as series circuits to a half-bridge circuit with a respective center tap ( 360 ) between the respective magnetoresistive sensor elements ( 120 ) are coupled. Method for detecting one of a donor object ( 150 ) generated or influenced at least sections of periodic magnetic field with a first, second, third and fourth magnetoresistive sensor element ( 120 ), wherein the first and the second magnetoresistive sensor element ( 120 ) adjacent at a first distance ( 400 ), wherein the third and the fourth magnetoresistive sensor element ( 120 ) adjacent at a second distance ( 410 ), wherein the first and the third magnetore sistive sensor element at a third distance ( 420 ), the first distance ( 400 ) and the second distance ( 410 ) having a smallest absolute phase difference with respect to the periodic magnetic field of at least 1 ° and less than 90 °, and wherein the third distance ( 420 ) corresponds to a minimum absolute phase difference of at least 25 °, comprising: providing a sum signal based on a first difference of signals of the first and third magnetoresistive sensor elements ( 120 ) and a second difference of signals of the second and fourth magnetoresistive sensor elements ( 120 ) that provides information regarding the speed of the encoder object ( 150 ) having; and providing a difference signal based on the first difference and the second difference, the information relating to a direction of the speed of the encoder object ( 150 ) having. The method of claim 24, further comprising integrating the difference signal such that the integrated difference signal is the information relating to the direction of the encoder object. 150 ) having. The method of claim 25, further comprising detection a minimum or a maximum of the sum signal comprises and a reset the integration of the difference signal, if a maximum or a Minimum of the sum signal is present. Method for detecting one of a donor object ( 150 ) generated or influenced, at least in sections, periodic magnetic field with a first, second and third magnetoresistive sensor element ( 120 ), wherein the first and the second magnetoresistive sensor element ( 120 ) adjacent at a first distance ( 400 ), wherein the second and the third magnetoresistive sensor element ( 120 ) at a second distance ( 560 ), the first distance ( 400 ) correspond to a minimum absolute phase difference with respect to the periodic magnetic field of at least 1 ° and less than 90 °, and wherein the second distance ( 560 ) corresponds to a minimum absolute phase difference of at least 25 °, comprising: providing a sum signal based on a first difference of signals of the first and third magnetoresistive sensor elements ( 120 ) and a second difference of signals of the second and third magnetoresistive sensor elements ( 120 ) that provides information regarding the speed of the encoder object ( 150 ) having; and providing a difference signal based on the first difference and the second difference, the information relating to a direction of the speed of the encoder object ( 150 ) having. The method of claim 27, further comprising integrating the difference signal such that the integrated difference signal is the information relating to the direction of the encoder object. 150 ) having. The method of claim 28, further comprising detection a minimum or a maximum of the sum signal comprises and a reset the integration of the difference signal, if a maximum or a Minimum of the sum signal is present. Sensor arrangement ( 110 ) for capturing one of a donor object ( 150 ) generated or influenced at least sections of periodic magnetic field, with the following features: a first, second, third and fourth magnetoresistive sensor element ( 120 ), wherein the first and the second magnetoresistive sensor element ( 120 ) at a first distance ( 580 ) are arranged; wherein the second and the third magnetoresistive sensor element ( 120 ) at a second distance ( 590 ) are arranged; wherein the third and the fourth magnetoresistive sensor element ( 120 ) at a third distance ( 600 ) are arranged; where the first distance ( 580 ) and the third distance ( 600 ) corresponds to a minimum absolute phase difference with respect to the periodic magnetic field of at least 20 °; and wherein the second distance ( 590 ) corresponds to a minimum absolute phase difference with respect to the periodic magnetic field of at most 40 °. Sensor arrangement ( 110 ) according to claim 30, wherein the first, second, third and fourth magnetoresistive sensor elements ( 120 ) parallel on a line with respect to a main detection direction ( 390 ) of the sensor arrangement are arranged. Sensor arrangement according to one of claims 30 or 31, wherein the first, second, third and fourth magnetoresistive sensor element ( 120 ) have a common preferred direction with respect to the detection of magnetic fields. Sensor arrangement ( 110 ) according to one of claims 30 to 32, in which the first, second, third and fourth magnetoresistive sensor elements ( 120 ) have conditioning with respect to a common direction. Sensor arrangement ( 110 ) according to one of claims 30 to 33, in which the sensor arrangement ( 110 ) Furthermore, an evaluation circuit ( 350 configured to be based on a first difference signal of the first and second magnetoresistive sensor elements ( 120 ) and based on a second difference signal of the third and the fourth sensor element ( 120 ) provide a sum signal and a difference signal, wherein the sum signal information with respect to a speed of the encoder object ( 150 ), and wherein the difference signal information with respect to a direction of the encoder object ( 150 ) having. Sensor arrangement ( 110 ) according to claim 34, wherein the evaluation circuit ( 350 ) has a sample and hold circuit configured to receive at one input the sum signal and to provide at one output a direction signal based on the sum signal, the evaluation circuit being further configured to provide a clock signal to the sample and hold circuit the difference signal has a zero crossing. Sensor arrangement ( 110 ) according to one of claims 30 to 35, in which the first distance ( 580 ) and the third distance ( 600 ) is less than 20% of the first distance ( 580 ). Method for detecting one of a donor object ( 150 ) generated or influenced at least sections of periodic magnetic field with a first, second, third and fourth magnetoresistive sensor element ( 120 ), wherein the first and the second magnetoresistive sensor element ( 120 ) at a first distance ( 580 ), wherein the second and the third magnetoresistive sensor element ( 120 ) at a second distance ( 590 ), wherein the third and the fourth magnetoresistive sensor element ( 120 ) at a third distance ( 600 ), wherein the first stand from ( 580 ) and the third distance ( 600 ) corresponds to a minimum absolute phase difference with respect to the periodic magnetic field of at least 20 °, and wherein the second distance ( 590 ) corresponds to a minimum absolute phase difference with respect to the periodic magnetic field of at most 40 °, comprising: providing a sum signal based on a first difference of signals of the first and second magnetoresistive sensor elements ( 120 ) and based on a second difference of signals of the third and the fourth magnetoresistive sensor element ( 120 ), wherein the sum signal contains information relating to a speed of the encoder object ( 150 ) having; and providing a difference signal based on the first difference and the second difference, the difference signal having information regarding a direction of the speed of the encoder object ( 150 ) having. Sensor arrangement ( 110 ) for capturing one of a donor object ( 150 ) generated or influenced at least sections of periodic magnetic field, with the following features: a first, second, third and fourth magnetoresistive sensor element ( 120 ), wherein the first and the second magnetoresistive sensor element ( 120 ) adjacent at a first distance ( 400 ) are arranged; wherein the third and the fourth magnetoresistive sensor element ( 120 ) adjacent at a second distance ( 410 ) are arranged; wherein the first and third magnetoresistive sensor elements ( 120 ) at a third distance ( 420 ) are arranged; and wherein the first distance ( 400 ) and the second distance ( 410 ) at least 1% of the third distance ( 420 ) and less than 50% of the third distance ( 420 ) is. Sensor arrangement ( 110 ) according to claim 38, wherein the first, second, third and fourth magnetoresistive sensor elements ( 120 ) parallel on a line with respect to a main detection direction ( 390 ) of the sensor arrangement ( 110 ) are arranged. Sensor arrangement ( 110 ) according to one of claims 38 or 39, wherein the sensor arrangement further an evaluation circuit ( 350 ) configured to determine, based on a first difference signal of the first and third magnetoresistive sensor elements ( 120 ) and based on a second difference signal of the second and the fourth magnetoresistive sensor element ( 120 ) provide a sum signal and a difference signal, wherein the sum signal information with respect to a speed of the encoder object ( 150 ), wherein the difference signal information with respect to a direction of the speed of the encoder object ( 150 ) having. Sensor arrangement according to Claim 40, in which the evaluation circuit ( 350 ) an integrator ( 520 ), which is configured to aufintegrieren the difference signal, and in which the evaluation circuit ( 350 ) is further configured so that the integrated difference signal information with respect to the direction of the speed of the encoder object ( 190 ) having. Sensor arrangement ( 110 ) according to claim 41, wherein the evaluation circuit further comprises a minimum / maximum detector ( 540 ) which is connected to the integrator ( 520 ) is configured and configured in such a way that, in the presence of a maximum or a minimum of the sum signal, the integrator ( 520 ) reset. Sensor arrangement ( 110 ) according to one of claims 38 to 42, at the third distance ( 420 ) a period length of an at least partially over a part of an outer dimension of a donor object ( 150 ) corresponds to distributed periodic structure. Sensor arrangement ( 110 ) for capturing one of a donor object ( 150 ) generated or influenced at least sections of periodic magnetic field, with the following features: a first, second and third magnetoresistive sensor element ( 120 ), wherein the first and the second magnetoresistive sensor element ( 120 ) adjacent at a first distance ( 400 ) are arranged; wherein the second and the third magnetoresistive sensor element ( 120 ) at a second distance ( 560 ) are arranged; and wherein the first distance ( 400 ) at least 1% of the second distance ( 560 ) and less than 50% of the second distance ( 560 ) corresponds. Sensor arrangement ( 110 ) according to claim 44, wherein the first, second and third magnetoresistive sensor elements ( 120 ) parallel on a line with respect to a main detection direction ( 390 ) of the sensor arrangement ( 110 ) are arranged. Sensor arrangement ( 110 ) according to claim 45, wherein the sensor arrangement further comprises an evaluation circuit ( 350 ) configured to determine, based on a first difference signal of the first and third magnetoresistive sensor elements ( 120 ) and based on a second difference signal of the second and the third magnetoresistive sensor element ( 120 ) provide a sum signal and a difference signal, wherein the sum signal information with respect to a speed of the encoder object ( 150 ), wherein the difference signal information with respect to a direction of the speed of the encoder object ( 150 ) having. Sensor arrangement ( 110 ) according to claim 46, wherein the evaluation circuit ( 350 ) an integrator ( 520 ), which is configured to aufintegrieren the difference signal, and in which the evaluation circuit ( 350 ) is further configured so that the integrated difference signal information with respect to the direction of the speed of the encoder object ( 150 ) having. Sensor arrangement ( 110 ) according to claim 47, wherein the evaluation circuit further comprises a minimum / maximum detector ( 540 ) which is connected to the integrator ( 520 ) is configured and configured in such a way that, in the presence of a maximum or a minimum of the sum signal, the integrator ( 520 ) reset. Sensor arrangement ( 110 ) according to one of claims 44 to 48, wherein the second distance ( 560 ) a period length of an at least partially over a part of an outer dimension of a donor object ( 150 ) corresponds to distributed periodic structure. Sensor ( 100 ) for capturing one of a donor object ( 150 ) generated or influenced at least sections of periodic magnetic field, with the following features: a first, second, third and fourth magnetoresistive sensor element ( 120 ); and an evaluation circuit ( 350 ) configured to determine, based on a first difference signal of the first and second magnetoresistive sensor elements ( 120 ) and based on a second difference signal of the third and the fourth sensor element ( 120 ) provide a sum signal and a difference signal, wherein the sum signal information with respect to a speed of the encoder object ( 150 ), and wherein the difference signal information with respect to a direction of the encoder object ( 150 ), wherein the first and the second magnetoresistive sensor element ( 120 ) at a first distance ( 580 ) are arranged; wherein the second and the third magnetoresistive sensor element ( 120 ) at a second distance ( 590 ) are arranged; wherein the third and the fourth magnetoresistive sensor element ( 120 ) at a third distance ( 600 ) are arranged. A sensor according to claim 50, wherein the second distance ( 590 ) is less than 50% of the first distance ( 580 ) having. Sensor according to one of claims 50 or 51, in which the third distance ( 600 ) has a length of at least 50% and not more than 200% of the first distance ( 580 ) having. Sensor according to one of claims 50 to 52, wherein the first and the second sensor element ( 120 ) via one with the evaluation circuit ( 350 ) coupled nodes are connected in series and in which the third and the fourth sensor element ( 120 ) via one with the evaluation circuit ( 350 ) coupled nodes are connected in series. Program with a program code for performing a the method of any one of claims 24, 27 or 37 when the Program runs on a processor.