Sensor devices, methods for their manufacture and methods for detecting electrical currents

Abstract

A sensor device comprises an electrically conductive substrate and a magnetic field sensor mounted on the electrically conductive substrate. The magnetic field sensor includes a first pair of first sensor elements designed to provide a first differential signal representative of a magnetic field generated by an electric current through an electrical conductor and by eddy currents generated in the electrically conductive substrate. The magnetic field sensor further comprises a second pair of second sensor elements designed to provide a second differential signal representative of a magnetic field generated by the eddy currents and independent of a magnetic field generated by the electric current through the electrical conductor.The sensor device further includes a unit designed to provide an output signal based on a difference or sum containing the first differential signal and the second differential signal.

Description

Technical FieldThe present disclosure relates to sensor devices and methods of manufacturing sensor devices. In addition, the present disclosure relates to methods for detecting electrical currents.BackgroundMagnetic field sensors may be used to sense electrical currents flowing through electrical conductors, such as PCB traces or bus bars. Temporal fluctuations of the electrical currents may result in eddy currents (eddy currents) induced in electrically conductive components of the sensor device, such as in a leadframe. These undesired eddy currents can degrade the measurement signal of the sensor device. In the worst case, eddy currents induced in a lead frame of the sensor device may lead to a deterioration of the accuracy and / or undesired events such as an unintentional activation of an overcurrent detection. Manufacturers and designers of sensor devices are constantly striving to improve their products. In particular, it may be desirable to develop sensor devices that provide measurement results independent of induced eddy currents. In addition, it may be desirable to provide methods of manufacturing such sensor devices and methods of detecting electrical currents that may be performed by such sensor devices.SummaryAn aspect of the present disclosure relates to a sensor device. The sensor device comprises an electrically conductive carrier and a magnetic field sensor mounted on the electrically conductive carrier. The magnetic field sensor comprises a first pair of first sensor elements configured to provide a first differential signal representative of a magnetic field generated by an electric current through an electric conductor and by eddy currents generated in the electrically conductive carrier. The magnetic field sensor further comprises a second pair of second sensor elements configured to provide a second differential signal representative of a magnetic field generated by the eddy currents and independent of a magnetic field generated by the electric current through the electrical conductor. The sensor device further comprises a unit configured to provide an output signal based on a difference or a sum including the first differential signal and the second differential signal.Another aspect of the present disclosure relates to a sensor device. The sensor device comprises an electrically conductive carrier and a magnetic field sensor mounted on the electrically conductive carrier. The magnetic field sensor comprises a first pair of first sensor elements configured to provide a first differential signal, wherein the first sensor elements are separated from each other in a first direction, and wherein each of the first sensor elements is sensitive to magnetic fields in the first direction. The magnetic field sensor further comprises a second pair of second sensor elements configured to provide a second differential signal, wherein the second sensor elements are separated from each other in a second direction perpendicular to the first direction, and wherein each of the second sensor elements is sensitive to magnetic fields in the second direction. The sensor device further comprises a unit configured to provide an output signal based on a difference or a sum including the first differential signal and the second differential signal.Another aspect of the present disclosure relates to a method for detecting an electric current through an electric conductor by means of a magnetic field sensor mounted on an electrically conductive carrier. The method includes an action of detecting, by a first pair of first sensor elements of the magnetic field sensor, a first differential signal representative of a magnetic field generated by the electrical current through the electrical conductor and by eddy currents generated in the electrically conductive carrier. The method further comprises an action of detecting, by a second pair of second sensor elements of the magnetic field sensor, a second differential signal representative of a magnetic field generated by the eddy currents and independent of a magnetic field generated by the electric current through the electrical conductor. The method further comprises an action of providing an output signal based on a difference or a sum including the first differential signal and the second differential signal.Another aspect of the present disclosure relates to a method for manufacturing a sensor device. The method includes an act of manufacturing a magnetic field sensor. The manufacturing of the magnetic field sensor includes an act of manufacturing a first pair of first sensor elements configured to provide a first differential signal, wherein the first sensor elements are separated from each other in a first direction and wherein each of the first sensor elements is sensitive to magnetic fields in the first direction. The manufacturing of the magnetic field sensor further comprises an act of manufacturing a second pair of second sensor elements configured to provide a second differential signal, wherein the second sensor elements are separated from each other in a second direction perpendicular to the first direction and wherein each of the second sensor elements is sensitive to magnetic fields in the second direction. The manufacturing of the magnetic field sensor further includes an action of manufacturing a unit configured to provide an output signal based on a difference or a sum including the first differential signal and the second differential signal. The method further comprises an act of providing an electrically conductive carrier. The method further includes an act of mounting the magnetic field sensor on the electrically conductive carrier.Brief Description of the DrawingsApparatuses and methods according to the disclosure will be described in more detail below based on the drawings. Like reference numerals may designate corresponding like parts. The technical features of the various illustrated examples may be combined unless they are mutually exclusive and / or may be selectively omitted unless described as necessarily required. Some of the drawings may include a scale (e.g., in mm units) to indicate the size of the components illustrated therein. The scales and lengths of the components shown are exemplary and in no way limiting. FIG. 1 includes FIGS. 1A and 1B illustrating a perspective view and a plan view of a sensor device 100 according to the disclosure. FIG. 2 is a block diagram of a circuit 200 that may be included in a sensor device according to the disclosure. FIG. 3 includes FIGS. 3A to 3C illustrating output signals from various sensor devices. FIG. 4 illustrates a top view of a sensor device 400 according to the disclosure. FIG. 5 illustrates a flow chart for a method of manufacturing a sensor device in accordance with the disclosure. FIG. 6 illustrates a flow diagram of a method for detecting an electric current according to the disclosure.Detailed DescriptionThe sensor device 100 of FIG. 1 may include an electrically conductive carrier 2 and a magnetic field sensor 4 mounted thereon. The magnetic field sensor 4 may include a first pair of sensor elements (or sensing elements) 6A, 6B and a second pair of sensor elements 8A, 8B. Optionally, the electrically conductive carrier 2 and the magnetic field sensor 4 may be at least partially encapsulated by an encapsulation material 10. The sensor device 100 may be disposed over (or mounted on) an electrical conductor 12, which may or may not be considered part of the sensor device 100.The magnetic field sensor 4 may be configured to provide differential signals, as will be explained later, and may thus be referred to as a differential magnetic field sensor. The differential sensing concepts discussed herein may be configured to cancel homogenous stray magnetic fields. In addition, the magnetic field sensor 4 can correspond to an integrated circuit or a semiconductor chip, so that it can also be referred to as an integrated magnetic field sensor circuit or magnetic field sensor chip. In the illustrated example, the upper main surface and the lower main surface of the magnetic field sensor 4 may be disposed in the x-y plane.The first sensor elements 6A and 6B may be separated from each other in a first direction, i.e., a straight line connecting the first sensor elements 6A and 6B may be parallel to the first direction. In the illustrated example, the first direction may correspond to the x direction. Each of the first sensor elements 6A and 6B may be sensitive to magnetic fields in the x-direction. That is, each of the first sensor elements 6A and 6B may be configured to detect the x-component of a magnetic field present at the location of the respective sensor element. In the following, the first sensor elements 6A and 6B may also be referred to as "right" and "left" sensor elements, respectively. It should be noted that, due to the selected coordinate system of FIG. 1B, the sensor element 6A on the left may be referred to as a "right" sensor element, while the sensor element 6B on the right may be referred to as a "left" sensor element 6B. In further examples, however, the designation of the sensor elements 6A and 6B can also be chosen differently.Similarly, the second sensor elements 8A and 8B may be separated from each other in a second direction substantially perpendicular to the first direction. That is, a straight line connecting the second sensor elements 8A and 8B may be parallel to the second direction. In the illustrated example, the second direction may correspond to the y-direction. Each of the second sensor elements 8A and 8B may be sensitive to magnetic fields in the y-direction. That is, each of the second sensor elements 8A and 8B may be configured to detect the y-component of a magnetic field present at the location of the respective sensor element. In the following, the second sensor elements 8A and 8B may also be referred to as "upper" and "lower" sensor elements, respectively.For example, the first sensor elements 6A, 6B and the second sensor elements 8A, 8B may be arranged in the x-y plane, i.e. they may have a same z-coordinate. In the illustrated case, a pitch (or distance) between the first sensor elements 6A and 6B may be substantially equal to a pitch between the second sensor elements 8A and 8B. Accordingly, the four sensor elements 6A, 6B and 8A, 8B may be arranged on a circle. In further examples, a pitch between the second sensor elements 8A and 8B may be increased or decreased, such that the four sensor elements 6A, 6B and 8A, 8B may be arranged on an ellipse in such cases.In an example, each of the sensor elements 6A, 6B and 8A, 8B may be separately implemented as a resistor bridge, which may include an example number of four resistors. In general, the magnetic field sensor 4 and its sensor elements 6A, 6B and 8A, 8B are not limited to a specific sensor technology. For example, the sensor elements 6A, 6B and 8A, 8B may be magnetoresistive xMR sensor elements, such as AMR sensor elements, GMR sensor elements or TMR sensor elements. In this regard, the first sensor elements 6A, 6B and the second sensor elements 8A, 8B may correspond to in-plane magnetoresistive elements (or current-in-plane (CIP) magnetoresistive elements). In further examples, the sensor elements 6A, 6B and 8A, 8B may be implemented as Hall sensor elements or fluxgate sensor elements.The sensor elements 6A, 6B and 8A, 8B may be integrated into a circuit of a chip. Such a circuit may also be configured to perform at least one of signal amplification, analog-to-digital conversion, digital signal processing, or offset and temperature compensation. In addition to the components of the respective sensor element, components for signal amplification and / or analog-to-digital conversion can be regarded as part of the sensor elements 6A, 6B and 8A, 8B or not. An exemplary circuit and a more detailed embodiment of sensor elements are shown and discussed in connection with FIG. 2.The electrical conductor 12 is not limited to a particular type, shape, or material, and may be, for example, a conductive trace, a printed circuit board trace, a bus bar, a bus bar, or the like. In the illustrated case, the electrical conductor 12 may exemplarily correspond to a conductive trace disposed on an upper surface of a multi-layer circuit board. The electrical conductor 12 of FIG. 1 (or the illustrated portion thereof) may have a substantially linear shape and extend in the y-direction, for example. In other examples, the electrical conductor 12 may have a different shape, such as a U-shape, as shown and discussed in connection with the example of FIG. 4 described later.As can be seen in the plan view of FIG. 1B, the electrical conductor 12 and the sensor device 100 can be aligned with one another. In this connection, an edge of the electric conductor 12 and a connecting line between the second sensor elements 8A and 8B may be aligned with each other. In particular, the right edge of the electrical conductor 12 and the connecting line between the second sensor elements 8A and 8B may be congruent. Moreover, the first sensor elements 6A and 6B may be arranged symmetrically with respect to the right edge of the electrical conductor 12. That is, the shortest distance between the sensor element 6A and the right edge of the electric conductor 12 may be substantially equal to the shortest distance between the sensor element 6B and the right edge of the electric conductor 12. A straight line connecting the sensor elements 6A and 6B may be substantially perpendicular to the right edge of the electrical conductor 12.The electrically conductive carrier 2 is not limited to a specific type, shape or material. For example, the carrier 2 may correspond to a lead frame, which may be made of metals and / or metal alloys, in particular of at least one of copper, copper alloys, nickel, iron-nickel or the like. In the illustrated case, the leadframe 2 may exemplarily include a die pad 14 and two rows of leads (or pins or fingers) 16A, 16B arranged on opposite sides of the die pad 14. In further examples, the number and arrangement of the die pads and leads may be chosen differently.In the illustrated example, the die pad 14 may be disposed in the x-y plane. The left edge and the right edge of the die pad 14 may extend in the y-direction, and the top edge and the bottom edge of the die pad 14 may extend at least partially in the x-direction. In the plan view of FIG. 1B, a center (or geometric center) of the magnetic field sensor 4 and a center (or geometric center) of the electrically conductive carrier 2 (or of the die pad 14) may be congruent. Each row of leads 16A and 16B may include a plurality of paralleled leads, each of the leads 16A and 16B may extend substantially in the x-direction. In the non-limiting illustrated example, the leads 16A and 16B may be a "gull wing" type, and the sensor device 100 may correspond to a surface mount device.In the illustrated case, the magnetic field sensor 4 can be arranged, for example, between the electrical conductor 12 and the electrically conductive carrier 2. In particular, the magnetic field sensor 4 may be mounted on the bottom surface of the die pad 14, i.e. the magnetic field sensor 4 may be mounted in a bottom die configuration. In further examples, the electrically conductive carrier 14 can alternatively also be arranged between the electrical conductor 2 and the magnetic field sensor 4. In particular, the magnetic field sensor 4 may then be mounted in a top-die configuration, i.e. the magnetic field sensor 4 may be mounted on the top side of the die pad 14.The encapsulation material 10 may include or be made from at least one mold compound, an epoxy, a filled epoxy, an epoxy filled with glass fibers, an imide, a thermoplastic, a thermosetting polymer, a polymer blend, a laminate, or the like. The encapsulation material 10 may be formed based on at least one of compression molding, injection molding, powder molding, liquid molding, map molding, laminating, or the like. The encapsulation material 10 may be configured to protect encapsulated components of the device from threats such as mechanical shocks, chemical contamination, light exposure, etc. In the illustrated example, the encapsulation material 10 may form a body or an encapsulation having two opposing main surfaces extending in the x-y plane. Due to such encapsulation, the sensor device 100 may also be referred to as a sensor package.The electrically conductive carrier 2, the magnetic field sensor 4 and the connection conductors 16A, 16B may be at least partially encapsulated in the encapsulation material 10. In contrast, the electrical conductor 12 may be an off-package component, i.e. it may be arranged external to the encapsulation material 10. It is noted that in the top view of FIG. 1B, for purposes of illustration, the encapsulation material 10 is not shown so as not to obscure components of the device embedded therein.Electrical contacts 18 of the magnetic field sensor chip 4 can be connected to one or more of the connection conductors 16B via electrical connection elements 20. In the illustrated example, the electrical connection elements 20 may correspond to wires. In further examples, the electrical connectors 20 may include straps, clips, or the like. As can be seen from the perspective view of FIG. 1A, the connection conductors 16A and 16B can protrude at least partially from the encapsulation material 10, such that the encapsulated magnetic field sensor 4 can be electrically accessible from outside the encapsulation material 10.An exemplary operation of the sensor device 100 will be described below. During such operation, an electrical current may flow through the electrical conductor 12. An output signal of the sensor device 100 based on a measurement of the sensor elements 6A, 6B and 8A, 8B may be used to determine the magnitude of the electric current. In particular, the electrical current can be variable over time and contain or correspond to, for example, fast transient signals, high-frequency alternating current signals, direct current signals with ripple (ripple) or the like. In the illustrated example, the electrical conductor 12 may extend in the y-direction such that magnetic fields generated by electrical currents through the electrical conductor 12 may lie in the x-z plane. In addition, in the case of time-variable electrical currents, eddy currents can be induced in the electrically conductive carrier 2, in particular in the die pad 14.The first pair of first sensor elements 6A and 6B may be configured to provide a first differential signal based on the magnetic field detected at the locations of the first sensor elements 6A and 6B, respectively. In particular, the first differential signal may correspond to a difference B Rechts- B Links where B Rechts and B Links may characterize the (x-components) of the detected magnetic fields at the first sensor elements 6A and 6B, respectively (or the respective detection signals). The magnetic fields at the locations of the first sensor elements 6A and 6B may include the magnetic field generated by the electric current through the electric conductor 12. In addition, the eddy currents induced in the electrically conductive carrier 2 (or in the die pad 14) can generate differential magnetic fields at the location of the first sensor elements 6A and 6B, which are superimposed with the magnetic field of the external conductor 12. As a result, the first differential signal provided by the first sensor elements 6A and 6B may be representative of the magnetic field generated by the electric current through the electric conductor 12 and by the eddy currents generated in the electrically conductive carrier 2.Similarly, the second pair of second sensor elements 8A and 8B may be configured to provide a second differential signal based on the magnetic field sensed at the locations of the second sensor elements 8A and 8B, respectively. In particular, the second differential signal may correspond to a difference B Oben- B Unten where B Oben and B Unten may characterize the (y-components) of the detected magnetic fields at the second sensor elements 8A and 8B (or the respective detection signals). The magnetic field generated by the electric current through the electric conductor 12 may be in the x-z plane, but may not have a magnetic field component in the y direction. Due to their sensitivity in the y-direction, the second sensor elements 8A and 8B therefore cannot detect a magnetic field generated by the electric current through the electric conductor 12. Consequently, the second differential signal provided by the second sensor elements 8A and 8B may be representative of the magnetic field generated by the eddy currents and independent of the magnetic field generated by the electric current through the electric conductor 12.As discussed below, the first and second differential signals may be used to provide an output signal that is independent of the magnetic field generated by the eddy currents. The output signal may be representative of the magnitude of the electrical current through the electrical conductor 12. To this end, the sensor device 100 may include a unit configured to provide an output signal based on a difference or a sum including the first differential signal and the second differential signal. It is to be understood that an exemplary circuit for providing such an output signal will be shown and described later in connection with FIG. 2.The induced eddy currents can flow in a circular (or elliptical) shape in the electrically conductive carrier 2, in particular in the x-y plane of the die pad 14.In the case of a rotationally symmetrical electrically conductive carrier (or leadframe) 2 (e.g. having the shape of a circle), the differential magnetic field at the first pair of sensor elements 6A, 6B and the differential magnetic field at the second pair of sensor elements 8A, 8B may be substantially the same size. Therefore, the component generated by the eddy currents can cancel out by differentiating the first differential signal and the second differential signal. That is, an effect of the induced eddy currents may be intrinsically suppressed, and a corresponding output signal V out of the sensor device 100 may be independent of the magnetic field generated by the eddy currents. The output signal V out can thus be representative of the electrical current through the electrical conductor 12. For the case of a rotationally symmetrical carrier 2, the output signal V can correspond to outIn the case of a non-rotationally symmetrical, electrically conductive carrier (or leadframe) 2, the differential magnetic fields generated by the eddy currents are not necessarily of the same magnitude at the locations of the first pair of sensor elements 6A, 6B and at the locations of the second pair of sensor elements 8A, 8B. In this case, at least one of the first differential signal or the second differential signal may be scaled before the difference or sum of the two differential signals is formed. For example, one or both of the differential signals may be scaled using one or two variable gain amplifiers that provide scaling factors, such as shown and described in connection with FIG. 2. In general, the output signal V may then correspond to out wherein GainS and GainL are scaling factors, which may depend in particular on a geometry or shape of the electrically conductive carrier 2. In this way, a compensation of the contribution of the eddy currents to the specific geometry or shape of the electrically conductive carrier 2 can be adjusted.In a more specific case, to take into account the geometry of the electrically conductive carrier 2, only the scaling factor GainL for the second pair of sensor elements 8A and 8B may be taken into account, while the scaling factor GainS for the first pair of sensor elements 6A and 6B may be omitted (or set to a value of 1). The output signal V may then correspond to outAs described above, in determining an output signal V out various differences (or subtractions) of signals may need to be considered. In this connection, it should be noted that in some cases, a difference (or subtraction) of signals may be replaced by a corresponding sum of signals. For example, the difference B Rechts- B Links may need to be replaced by a sum B Rechts+ B Links when, for example, a sensitivity direction of the left sensor element 6B is inverted. Such a reversal of the sensitivity can lead to a sign change of the detected value B Links which must then be taken into account accordingly by forming a sum instead of a difference. Similarly, one or more of the differences given in equations (1) through (3) may be replaced with corresponding sums if changes in the sensitivities of one or more sensor elements involved require such replacement.Sensor devices according to the disclosure may provide various technical effects described below, and may exceed conventional sensor devices in various aspects.As discussed above, the sensor device 100 may provide an intrinsic scheme for compensating for effects on the output signal resulting from induced eddy currents. By applying this compensation scheme, the output signal of the sensor device 100 cannot be degraded by eddy currents occurring. As a result, a higher overall accuracy of the sensor device 100 can be provided compared to conventional sensor devices.In conventional sensor devices, eddy currents induced in an electrically conductive carrier can be avoided by interrupting the current paths of the eddy currents in the carrier. For this purpose, electrically conductive material of the carrier can be removed. For example, geometric features such as recesses, slots, notches or cavities, which are typically arranged in the immediate vicinity of the sensor elements, can prevent the generation of eddy currents. Such modifications of the carrier may be achieved by tool processes such as stamping, etching, laser cutting or the like. In particular, special tools may be required which may be time consuming and may result in increased overall cost in manufacturing. In addition, a requalification of a respective sensor device may be required each time a standard geometry of an electrically conductive carrier is replaced or modified.In contrast, sensor devices according to the disclosure may provide intrinsic eddy current compensation without having to change the geometric shape of the electrically conductive carrier. Returning to the example of FIG. 1, the electrically conductive carrier 2 (and in particular the die pad 14) of the sensor device 100 may be free of any features configured to interrupt current paths of eddy currents. Thus, compared to conventional sensor devices, manufacturing sensor devices according to the disclosure may be less time consuming and less expensive. In addition, the conventional requalification of devices can be omitted. Rather, standard sensor packages and / or standard geometries of electrically conductive carriers can be reused.As already discussed in connection with equations (2) and (3), the use of scaling factors can provide a simple and quick adaptation of the described eddy current compensation scheme to different device and carrier geometries. Sensor devices according to the disclosure may thus be realized for a variety of device and carrier geometries.Sensor devices according to the disclosure may be used in connection with many industrial and automotive applications. In particular, the concepts described herein may be used in connection with any application that relies on high-accuracy and fast input signals. Typical applications are, for example, high-voltage eFus, electrical circuit breakers or the like. The sensor devices described herein may be configured to be used in systems for detecting an electrical overcurrent event. In this context, a higher accuracy in the measurement of electrical currents can avoid, in particular, an unintentional activation of the detection of overcurrents.The circuit 200 of FIG. 2 may be included in a sensor device according to the disclosure, such as the sensor device 100 of FIG. 1, for example, the elements of the circuit 200 may be integrated into a same semiconductor chip. The circuit 200 may include a first (upper) signal path 22A and a second (lower) signal path 22B. Returning to the example of FIG. 1, circuit 200 may be configured to provide an output signal V out as indicated by, e.g., one of equations (1) through (3). In this connection, the first signal path 22A and the second signal path 22B may be configured to provide a first differential signal and a second differential signal, respectively, thereby taking into account scaling factors that may depend on a shape of the electrically conductive carrier 2, as described above.The first signal path 22A may include a first pair of first sensor elements 6A and 6B, which may be supplied with a supply voltage VDDS. For example, each of the first sensor elements 6A and 6B may include a bridge circuit (or resistance bridge). In the illustrated example, the respective bridge circuit may correspond to a Wheatstone bridge circuit that includes four resistors 24A- 24D. Each of the Wheatstone bridge circuits may have opposite or antiparallel sensitivity directions in the individual legs of the bridge, as indicated by arrows in resistors 24A- 24D.Note that an embodiment of the first sensor elements 6A and 6B is not limited to a specific design or type. In the illustrated example, the first sensor elements 6A and 6B may include two fully differential xMR bridges. In another example, the first sensor elements 6A and 6B may include a spatially distributed differential xMR bridge. In another example, the first sensor elements 6A and 6B may include one or more Hall sensor elements, which may be spatially distributed.The first signal path 22A may further include a first amplifier 26A configured to provide a gain factor GainS. The first amplifier 26A may be connected to the first sensor elements 6A and 6B (or the associated bridge circuits), as exemplarily shown in FIG. 2. In particular, a first (upper) input of the first amplifier 26A may be electrically coupled to a node 28A disposed between the two resistors 24A and 24D in the first branch of the first bridge circuit and to a node 28A disposed between the two resistors 24A and 24D in the first branch of the second bridge circuit. Additionally, a second (lower) input of the first amplifier 26A may be electrically coupled to a node 28B disposed between two resistors 24B and 24C in the second branch of the first bridge circuit and to a node 28B disposed between two resistors 24B and 24C in the second branch of the second bridge circuit.Each of the first sensor elements 6A and 6B (or the associated bridge circuits) may be configured to provide a differential signal. For example, the differential signals may correspond to differential (in particular analog) output voltages. The differential signals may be provided at the inputs of the first amplifier 26A, respectively. Returning to the example of FIG. 1, an output of the first amplifier 26A may correspond to the first differential signal representative of a magnetic field generated by an electric current through the electric conductor 12 and by eddy currents generated in the electrically conductive carrier 2. Note that the first amplifier 26A may be configured to amplify the first differential signal by the gain factor GainS. That is, an output of the first amplifier 26A may be GainS·(B Rechts- B Links). The output can correspond to an (in particular analog) output voltage.As can be seen from the exemplary block diagram of FIG. 2, the second signal path 22B may be at least partially similar to the first signal path 22A. In comparison with the first sensor elements 6A and 6B of the first signal path 22A, the resistors 24A to 24D of the second sensor elements 8A and 8B may have different orientations of sensitivity. In particular, the sensitivity directions of the resistors 24A- 24D in the second signal path 22B may be rotated counterclockwise by an angle of 90 degrees compared to the resistors 24A- 24D of the first signal path 22A.Each of the second sensor elements 8A and 8B (or the associated bridge circuits) may be configured to provide a differential signal. The differential signals may be provided at the inputs of a second amplifier 26B, respectively. Returning to the example of FIG. 1, an output of the second amplifier 26B may correspond to the second differential signal representative of a magnetic field generated by the eddy currents and independent of a magnetic field generated by the electrical current through the electrical conductor 12. Note that the second amplifier 26B may be configured to amplify the second differential signal by a gain factor GainL. Returning to the example of FIG. 1, the gain factor GainL of the second amplifier 26B may be based in particular on a shape or geometry of the electrically conductive carrier 2. An output of the second amplifier 26B may thus be GainL·(B Oben- B Unten). The output can correspond to an (in particular analog) output voltage.The circuit 200 may further include a third amplifier 30. An output of the first amplifier 26A may be coupled to a first (upper) input of the third amplifier 30. Similarly, an output of the second amplifier 26B may be coupled to a second (lower) input of the third amplifier 30. The third amplifier 30 can be designed to output a difference of the signals present at its two inputs. For example, an output may correspond to an output voltage (in particular analog). In the illustrated example, an output V may be out of the third amplifier 30FIG. 3 includes FIGS. 3A to 3C illustrating output signals of various sensing devices. The output signals illustrated were obtained with the aid of simulation software for the calculation of electric and magnetic fields. Each of FIGS. 3A to 3C includes a plurality of diagrams relating to different x-displacements of the magnetic field sensor 4 with respect to the right edge of the electrical conductor 12 (see, e.g., FIG. 1B ). An x-shift of 0 μm relates to the scenario of FIG. 1B. Furthermore, an x-displacement of, for example, +100 μm (-100 μm) relates to the scenario of FIG. 1B, wherein the magnetic field sensor 4 is displaced in the positive (negative) x-direction by a distance of 100 μm. It should be noted that the discussed x-displacements of the magnetic field sensor 4 may be undesirable and may occur, in particular, due to assembly tolerances.FIG. 3A shows output signals of a sensor device including a non-conductive carrier. Since no eddy currents can occur in the non-conductive carrier, the output signal is independent of effects generated in a similar device having an electrically conductive carrier. In this regard, the scenario of FIG. 3A may be considered ideal. The magnitude of the output signal B xRechts- B xLinks is plotted against frequency (of, e.g., fast transient signals). Changes in the output signals at higher frequencies may be due purely to the skin effect in the external electrical conductor 12.FIG. 3B shows output signals of a sensor device including an electrically conductive lead frame in which eddy currents can be induced. The magnitude of the output signal B xRechts- B xLinks is plotted against frequency (of, e.g., fast transient signals). As can be seen from FIG. 3B, the eddy currents induced in the leadframe can cause a considerable amplification at higher frequencies, which can reduce the accuracy of the measurement signals and result in a potential false triggering of the detection of overcurrents.FIG. 3C shows output signals of a sensor device including an electrically conductive lead frame in which eddy currents may occur, but which may be compensated based on the compensation scheme described above. An exemplary scaling factor GainL of 3.5 was used. Comparing the scenarios of FIGS. 3A and 3C, the benefit of the compensation scheme employed becomes clear. In the scenario of FIG. 3C, the effect of the eddy currents induced in the leadframe may be greatly reduced.The sensor device 400 of FIG. 4 may include some or all of the features of the sensor device 100 of FIG. 1. All annotations made in connection with the examples described above may also apply to the example of FIG. 4 and will not be discussed again for the sake of simplicity. A functioning of the sensor device 400 may be similar to a functioning of sensor devices described above.In comparison to FIG. 1, for example, the electrical conductor 12 of FIG. 4 may have a different shape. In the plan view of FIG. 4, the electrical conductor 12 may have a substantially rectangular shape including two notches 32A and 32B extending from the upper edge of the electrical conductor 12 in the negative y direction and a third notch 32C extending from the lower edge of the electrical conductor 12 in the positive y direction.In a region between the two notches 32A and 32B, the electric conductor 12 may include a U-shaped portion. The u-shaped portion of the electric conductor 12 may include a first portion disposed on the left side and extending in the y direction and a second portion disposed on the right side and extending in the y direction. In addition, the u-shaped portion of the electrical conductor 12 may include a third portion that extends in the x direction and connects the first portion and the second portion.The U-shaped portion of the electrical conductor 12 and the sensor device 400 may be aligned with one another. In this connection, the sensor element 6A of the first pair of sensor elements 6A, 6B may be disposed over the first portion of the u-shaped portion, and the second sensor element 6B of the first pair of sensor elements 6A, 6B may be disposed over the second portion of the u-shaped portion. Further, the second pair of sensor elements 8A and 8B may be disposed between the first portion and the second portion of the U-shaped portion, i.e., may be disposed over the third notch 32C.FIG. 5 illustrates a flow chart for a method of manufacturing a sensor device in accordance with the disclosure. The method may be used for manufacturing any of the sensor devices described above and may thus be read in connection with the preceding figures. In the following description, reference numerals of examples described above are used. The method is generally illustrated to qualitatively specify aspects of the present disclosure. The method may be extended by one or more aspects described in connection with other examples.At 34, a magnetic field sensor 4 may be manufactured. The manufacture of the magnetic field sensor 4 may include an act 34 aof manufacturing a first pair of first sensor elements 6A and 6B configured to provide a first differential signal, wherein the first sensor elements 6A and 6B are separated from each other in a first direction and wherein each of the first sensor elements 6A and 6B is sensitive to magnetic fields in the first direction. The manufacturing of the magnetic field sensor 4 may further include an act 34 bof manufacturing a second pair of second sensor elements 8A and 8B configured to provide a second differential signal, wherein the second sensor elements 8A and 8B are separated from each other in a second direction perpendicular to the first direction and wherein each of the second sensor elements 8A and 8B is sensitive to magnetic fields in the second direction. The manufacturing of the magnetic field sensor 4 may further include an act 34 cof manufacturing a unit configured to provide an output signal based on a difference or a sum including the first differential signal and the second differential signal. At 36, an electrically conductive carrier 2 may be provided. At 38, the magnetic field sensor 4 can be mounted on the electrically conductive carrier 2.FIG. 6 illustrates a flow diagram for a method according to the disclosure. The method can be carried out with each of the sensor devices described above and can thus be read in conjunction with the preceding figures. In the following description, reference numerals of the above-described examples are used. The method can be applied for detecting an electric current through an electric conductor 12 by means of a magnetic field sensor 4 mounted on an electrically conductive carrier 2. The method is illustrated in a general manner to qualitatively specify aspects of the present disclosure. The method may be extended by one or more aspects described in connection with other examples.At 40, a first differential signal representative of a magnetic field generated by the electric current through the electric conductor 12 and by eddy currents generated in the electrically conductive carrier 2 may be detected by a first pair of first sensor elements 6A and 6B of the magnetic field sensor 4. At 42, a second differential signal representative of a magnetic field generated by the eddy currents and independent of a magnetic field generated by the electric current through the electric conductor 12 may be detected by a second pair of second sensor elements 8A and 8B of the magnetic field sensor 4. At 44, an output signal may be provided based on a difference or a sum including the first differential signal and the second differential signal.ExamplesHereinafter, sensor devices, methods for manufacturing sensor devices, and methods for detecting electric currents will be explained by way of examples.Example 1 is a sensor device comprising: an electrically conductive carrier; a magnetic field sensor mounted on the electrically conductive carrier, the magnetic field sensor comprising: a first pair of first sensor elements configured to provide a first differential signal representative of a magnetic field generated by an electric current through an electric conductor and by eddy currents generated in the electrically conductive carrier, and a second pair of second sensor elements configured to provide a second differential signal representative of a magnetic field generated by the eddy currents and independent of a magnetic field generated by the electric current through the electric conductor; and a unit configured to provide an output signal based on a difference or a sum including the first differential signal and the second differential signal.Example 2 is a sensor device according to example 1, wherein the output signal is independent of the magnetic field generated by the eddy currents.Example 3 is a sensor device according to Example 1 or 2, wherein: the first sensor elements are separated from each other in a first direction and each of the first sensor elements is sensitive to magnetic fields in the first direction, and the second sensor elements are separated from each other in a second direction perpendicular to the first direction and each of the second sensor elements is sensitive to magnetic fields in the second direction.Example 4 is a sensor device according to example 3, wherein the electrical conductor extends in the second direction.Example 5 is a sensor device according to example 3 or 4, wherein an edge of the electrical conductor and a connecting line between the second sensor elements are congruent when viewed in a third direction perpendicular to the first direction and to the second direction.Example 6 is a sensor device according to example 5, wherein the first sensor elements are arranged symmetrically with respect to the edge of the electrical conductor.Example 7 is a sensor device according to example 3, wherein the electrical conductor comprises a U-shaped electrical conductor.Example 8 is a sensor device according to example 7, wherein the U-shaped electrical conductor comprises: a first portion and a second portion extending in the second direction, and a third portion extending in the first direction and connecting the first portion and the second portion.Example 9 is a sensor device according to example 8, wherein, viewed in a third direction perpendicular to the first direction and the second direction: a first sensor element of the first pair of sensor elements is arranged over the first portion and the second sensor element of the first pair of sensor elements is arranged over the second portion, and the second pair of sensor elements is arranged between the first portion and the second portion.Example 10 is a sensor device according to one of Examples 3 to 9, wherein the electrically conductive carrier is arranged in a plane defined by the first direction and the second direction.Example 11 is a sensor device according to one of Examples 3 to 10, wherein a center of the magnetic field sensor and a center of the electrically conductive carrier are congruent when viewed in a third direction perpendicular to the first direction and the second direction.Example 12 is a sensor device according to any of the preceding examples, further comprising: an amplifier configured to amplify the second differential signal, wherein a gain factor of the amplifier is based on a shape of the electrically conductive carrier.Example 13 is a sensor device according to any of the preceding examples, wherein: a first of the second sensor elements comprises a first bridge circuit including a first branch and a second branch, the second of the second sensor elements comprises a second bridge circuit including a first branch and a second branch, a first input of the amplifier is electrically coupled to a node arranged between two resistors in the first branch of the first bridge circuit and to a node arranged between two resistors in the first branch of the second bridge circuit, and a second input of the amplifier is electrically coupled to a node arranged between two resistors in the second branch of the first bridge circuit and to a node arranged between two resistors in the second branch of the second bridge circuit.Example 14 is a sensor device according to one of the preceding examples, wherein the magnetic field sensor is arranged between the electrical conductor and the electrically conductive carrier.Example 15 is a sensor device according to one of the preceding examples, wherein the electrically conductive carrier is free of any features configured to interrupt current paths of the eddy currents.Example 16 is a sensor device according to one of the preceding examples, wherein: the magnetic field sensor is encapsulated in an encapsulation material and the electrical conductor is arranged externally to the encapsulation material.Example 17 is a sensor device according to any of the preceding examples, wherein the sensor device is configured to be used in a system for detecting an electrical overcurrent event.Example 18 is a sensor device comprising: an electrically conductive carrier; a magnetic field sensor mounted on the electrically conductive carrier, the magnetic field sensor comprising: a first pair of first sensor elements configured to provide a first differential signal, wherein the first sensor elements are separated from each other in a first direction and wherein each of the first sensor elements is sensitive to magnetic fields in the first direction, and a second pair of second sensor elements configured to provide a second differential signal, wherein the second sensor elements are separated from each other in a second direction perpendicular to the first direction and wherein each of the second sensor elements is sensitive to magnetic fields in the second direction; and a unit configured to provide an output signal based on a difference or a sum including the first differential signal and the second differential signal.Example 19 is a sensor device according to example 18, wherein: the first differential signal is representative of a magnetic field generated by an electric current through an electric conductor and by eddy currents generated in the electrically conductive carrier, and the second differential signal is representative of a magnetic field generated by the eddy currents and is independent of a magnetic field generated by the electric current through the electric conductor, and the output signal is independent of the magnetic field generated by the eddy currents.Example 20 is a sensor device according to example 18 or 19, wherein the first sensor elements and the second sensor elements are arranged on a circle or an ellipse.Example 21 is a sensor device according to one of Examples 18 to 20, wherein the first sensor elements and the second sensor elements are in-plane magnetoresistive elements.Example 22 is a method for detecting an electric current through an electric conductor by means of a magnetic field sensor mounted on an electrically conductive carrier, the method comprising: detecting a first differential signal through a first pair of first sensor elements of the magnetic field sensor representative of a magnetic field generated by the electric current through the electric conductor and by eddy currents generated in the electrically conductive carrier; detecting a second differential signal through a second pair of second sensor elements of the magnetic field sensor representative of a magnetic field generated by the eddy currents and independent of a magnetic field generated by the electric current through the electric conductor; and providing an output signal based on a difference or a sum including the first differential signal and the second differential signal.Example 23 is a method of manufacturing a sensor device, the method comprising: manufacturing a magnetic field sensor, wherein manufacturing the magnetic field sensor comprises: manufacturing a first pair of first sensor elements configured to provide a first differential signal, wherein the first sensor elements are separated from each other in a first direction and wherein each of the first sensor elements is sensitive to magnetic fields in the first direction, and manufacturing a second pair of second sensor elements configured to provide a second differential signal, wherein the second sensor elements are separated from each other in a second direction perpendicular to the first direction and wherein each of the second sensor elements is sensitive to magnetic fields in the second direction; manufacturing a unit configured to provide an output signal based on a difference or a sum including the first differential signal and the second differential signal; providing an electrically conductive carrier; and mounting the magnetic field sensor on the electrically conductive carrier.Although the present disclosure has been described by way of illustrative examples, this description is not to be understood in a limited sense. Various modifications and combinations of the illustrative examples, as well as other examples of the disclosure, will be apparent to those skilled in the art from the description. It is therefore intended that the appended claims cover all such modifications or examples.

Claims

A sensor device comprising: an electrically conductive support (2); a magnetic field sensor (4) mounted on the electrically conductive support (2), the magnetic field sensor (4) comprising: a first pair of first sensor elements (6A, 6B) configured to provide a first differential signal representative of a magnetic field generated by an electric current through an electric conductor (12) and by eddy currents generated in the electrically conductive support (2) and a second pair of second sensor elements (8A, 8B) configured to provide a second differential signal representative of a magnetic field generated by the eddy currents and independent of a magnetic field generated by the electric current through the electric conductor (12); and a unit configured to provide an output signal based on a difference or a sum including the first differential signal and the second differential signal.The sensor device of claim 1, wherein the output signal is independent of the magnetic field generated by the eddy currents.The sensor device according to claim 1 or 2, wherein: the first sensor elements (6A, 6B) are separated from each other in a first direction and each of the first sensor elements (6A, 6B) is sensitive to magnetic fields in the first direction, and the second sensor elements (8A, 8B) are separated from each other in a second direction perpendicular to the first direction and each of the second sensor elements (8A, 8B) is sensitive to magnetic fields in the second direction.The sensor device of claim 3, wherein the electrical conductor (12) extends in the second direction.The sensor device according to claim 3 or 4, wherein an edge of the electrical conductor (12) and a connection line between the second sensor elements (8A, 8B) are congruent when viewed in a third direction perpendicular to the first direction and the second direction.Sensor device according to claim 5, wherein the first sensor elements (6A, 6B) are arranged symmetrically with respect to the edge of the electrical conductor (12).The sensor device according to claim 3, wherein the electrical conductor (12) comprises a U-shaped electrical conductor.The sensor device of claim 7, wherein the U-shaped electrical conductor comprises: a first portion and a second portion extending in the second direction, and a third portion extending in the first direction and connecting the first portion to the second portion.The sensor device according to claim 8, wherein when viewed in a third direction perpendicular to the first direction and the second direction: a first sensor element (6A) of the first pair of sensor elements (6A, 6B) is disposed over the first portion and the second sensor element (6B) of the first pair of sensor elements (6A, 6B) is disposed over the second portion, and the second pair of sensor elements (8A, 8B) is disposed between the first portion and the second portion.Sensor device according to one of Claims 3 to 9, wherein the electrically conductive carrier (2) is arranged in a plane which is defined by the first direction and the second direction.Sensor device according to one of Claims 3 to 10, wherein a center of the magnetic field sensor (4) and a center of the electrically conductive carrier (2) are congruent when viewed in a third direction perpendicular to the first direction and to the second direction.The sensor device according to any one of the preceding claims, further comprising: an amplifier (26B) configured to amplify the second differential signal, wherein a gain of the amplifier (26B) is based on a shape of the electrically conductive carrier (2).The sensor device of any preceding claim, wherein: a first one of the second sensor elements (8A, 8B) comprises a first bridge circuit including a first branch and a second branch; the second one of the second sensor elements (8A, 8B) comprises a second bridge circuit including a first branch and a second branch; a first input of the amplifier (26B) is electrically coupled to a node (28A) disposed between two resistors (24A, 24D) in the first branch of the first bridge circuit and to a node (28A) disposed between two resistors (24A, 24D) in the first branch of the second bridge circuit; and a second input of the amplifier (26B) is electrically coupled to a node (28B), which is arranged between two resistors (24B, 24C) in the second branch of the first bridge circuit, and with a node (28B) arranged between two resistors (24B, 24C) in the second branch of the second bridge circuit.Sensor device according to one of the preceding claims, wherein the magnetic field sensor (4) is arranged between the electrical conductor (12) and the electrically conductive carrier (2).Sensor device according to one of the preceding claims, wherein the electrically conductive carrier (2) is free of any features which are designed to interrupt current paths of the eddy currents.Sensor device according to one of the preceding claims, wherein: the magnetic field sensor (4) is encapsulated in an encapsulation material (10), and the electrical conductor (12) is arranged externally to the encapsulation material (10).The sensor device according to any of the preceding claims, wherein the sensor device is configured to be used in a system for detecting an electrical over-current event.A sensor device comprising: an electrically conductive support (2); a magnetic field sensor (4) mounted on the electrically conductive support (2), the magnetic field sensor (4) comprising: a first pair of first sensor elements (6A, 6B) configured to provide a first differential signal, wherein the first sensor elements (6A, 6B) are separated from each other in a first direction and wherein each of the first sensor elements (6A, 6B) is sensitive to magnetic fields in the first direction, and a second pair of second sensor elements (8A, 8B) configured to provide a second differential signal, wherein the second sensor elements (8A, 8B) are separated from each other in a second direction perpendicular to the first direction and wherein each of the second sensor elements (8A, 8B) is sensitive to magnetic fields in the second direction; and a unit configured to provide an output signal based on a difference or a sum including the first differential signal and the second differential signal.The sensor device according to claim 18, wherein: the first differential signal is representative of a magnetic field generated by an electric current through an electric conductor (12) and by eddy currents generated in the electrically conductive carrier (2), and the second differential signal is representative of a magnetic field generated by the eddy currents and independent of a magnetic field generated by the electric current through the electric conductor (12), and the output signal is independent of the magnetic field generated by the eddy currents.Sensor device according to Claim 18 or 19, wherein the first sensor elements (6A, 6B) and the second sensor elements (8A, 8B) are arranged on a circle or an ellipse.Sensor device according to one of Claims 18 to 20, wherein the first sensor elements (6A, 6B) and the second sensor elements (8A, 8B) are in-plane magnetoresistive elements.A method for detecting an electric current through an electric conductor (12) by means of a magnetic field sensor (4) mounted on an electrically conductive support (2), the method comprising: detecting, by a first pair of first sensor elements (6A, 6B) of the magnetic field sensor (4), a first differential signal representative of a magnetic field generated by the electric current through the electric conductor (12) and by eddy currents generated in the electrically conductive support (2); detecting, by a second pair of second sensor elements (8A, 8B) of the magnetic field sensor (4), a second differential signal representative of a magnetic field generated by the eddy currents and independent of a magnetic field generated by the electric current through the electric conductor (12); providing an output signal based on a difference or a sum including the first differential signal and the second differential signal.A method of manufacturing a sensor device, the method comprising: manufacturing a magnetic field sensor (4), wherein manufacturing the magnetic field sensor (4) comprises: manufacturing a first pair of first sensor elements (6A, 6B) configured to provide a first differential signal, wherein the first sensor elements (6A, 6B) are separated from each other in a first direction and wherein each of the first sensor elements (6A, 6B) is sensitive to magnetic fields in the first direction, and manufacturing a second pair of second sensor elements (8A, 8B) configured to provide a second differential signal, wherein the second sensor elements (8A, 8B) are separated from each other in a second direction perpendicular to the first direction and wherein each of the second sensor elements (8A, 8b) sensitive to magnetic fields in the second direction; manufacturing a unit configured to provide an output signal based on a difference or a sum including the first differential signal and the second differential signal; providing an electrically conductive carrier (2); and mounting the magnetic field sensor (4) on the electrically conductive carrier (2).

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