Sensor device, method for manufacturing the same, and method for sensing current

Abstract

The invention relates to a sensor device, a method of manufacturing the same, and a method for sensing current. A sensor device includes an electrically conductive carrier and a magnetic field sensor mounted on the electrically conductive carrier. The magnetic field sensor includes a first pair of first sensing elements configured to provide a first differential signal representative of a magnetic field generated by a current through the electrical conductor and by an eddy current generated in the electrically conductive carrier. The magnetic field sensor further includes a second pair of second sensing elements configured to provide a second differential signal representative of the magnetic field generated by the eddy current and independent of the magnetic field generated by the current through the electrical conductor. The sensor device further comprises a unit configured to provide an output signal based on a difference or / and comprising the first differential signal and the second differential signal.

Description

Technical Field

[0001] The present disclosure relates to a sensor device and a method for manufacturing a sensor device.Furthermore, the present disclosure relates to a method for sensing an electric current. Background Art

[0002] Magnetic field sensors can be used to sense current flowing through an electrical conductor, such as, for example, a PCB trace or busbar. Temporal variations in the current may cause eddy currents to be induced in conductive components of the sensor device, such as, for example, in a lead frame. These unwanted eddy currents may deteriorate the measurement signal of the sensor device. In the worst case, the eddy currents induced in the lead frame of the sensor device may result in reduced accuracy and / or unexpected events such as accidental activation of overcurrent detection. Manufacturers and designers of sensor devices are constantly working to improve their products. In particular, it may be desirable to develop a sensor device that provides measurement results that are independent of induced eddy currents. In addition, it may be desirable to provide methods for manufacturing such sensor devices and methods for sensing current that can be performed by such sensor devices. Summary of the invention

[0003] Aspects of the present disclosure relate to a sensor device. The sensor device includes a conductive carrier and a magnetic field sensor mounted on the conductive carrier. The magnetic field sensor includes a first pair of first sensing elements, which are configured to provide a first differential signal, the first differential signal representing a magnetic field generated by a current through the electrical conductor and by eddy currents generated in the conductive carrier. The magnetic field sensor also includes a second pair of second sensing elements, which are configured to provide a second differential signal, the second differential signal representing a magnetic field generated by the eddy currents and independent of the magnetic field generated by the current through the electrical conductor. The sensor device also includes a unit configured to provide an output signal based on a difference or a sum of the first differential signal and the second differential signal.

[0004] Another aspect of the present disclosure relates to a sensor device. The sensor device includes a conductive carrier and a magnetic field sensor mounted on the conductive carrier. The magnetic field sensor includes a first pair of first sensing elements configured to provide a first differential signal, wherein the first sensing elements are separated from each other in a first direction, and wherein each of the first sensing elements is sensitive to a magnetic field in the first direction. The magnetic field sensor also includes a second pair of second sensing elements configured to provide a second differential signal, wherein the second sensing elements are separated from each other in a second direction perpendicular to the first direction, and wherein each of the second sensing elements is sensitive to a magnetic field in the second direction. The sensor device also includes a unit configured to provide an output signal based on a difference or a sum of the first differential signal and the second differential signal.

[0005] Another aspect of the present disclosure relates to a method for sensing a current through an electrical conductor by a magnetic field sensor mounted on a conductive carrier. The method includes the act of sensing a first differential signal by a first pair of first sensing elements of the magnetic field sensor, the first differential signal representing a magnetic field generated by the current through the electrical conductor and by eddy currents generated in the conductive carrier. The method also includes the act of sensing a second differential signal by a second pair of second sensing elements of the magnetic field sensor, the second differential signal representing a magnetic field generated by the eddy currents and independent of the magnetic field generated by the current through the electrical conductor. The method also includes the act of providing an output signal based on a difference or sum including the first differential signal and the second differential signal.

[0006] Another aspect of the present disclosure relates to a method for manufacturing a sensor device. The method includes an act of producing a magnetic field sensor. Producing the magnetic field sensor includes an act of producing a first pair of first sensing elements, the first pair of first sensing elements being configured to provide a first differential signal, wherein the first sensing elements are separated from each other in a first direction, and wherein each of the first sensing elements is sensitive to a magnetic field in the first direction. Producing the magnetic field sensor also includes an act of producing a second pair of second sensing elements, the second pair of second sensing elements being configured to provide a second differential signal, wherein the second sensing elements are separated from each other in a second direction perpendicular to the first direction, and wherein each of the second sensing elements is sensitive to a magnetic field in the second direction. Producing the magnetic field sensor also includes an act of producing 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 also includes an act of providing a conductive carrier. The method also includes an act of mounting the magnetic field sensor on the conductive carrier. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The following describes the device and method according to the present disclosure in more detail based on the accompanying drawings. Similar reference signs can designate corresponding similar parts. As long as the technical features of the various illustrated examples are not mutually exclusive, they can be combined, and / or if they are not described as required, they can be selectively ignored. Some drawings may include scales (e.g., in mm) for indicating the sizes of the components illustrated herein. It should be noted that the scales and component lengths shown are exemplary and are not limiting.

[0008] Figure 1 includes Figure 1A and Figure 1B , which illustrates a perspective view and a top view of a sensor device 100 according to the present disclosure.

[0009] Figure 2 is a block diagram of a circuit arrangement 200 , which may be included in a sensor device according to the present disclosure.

[0010] Figure 3 includes FIG. 3A to FIG. 3C, which illustrates the output signals of various sensor devices.

[0011] Figure 4 A top view of a sensor device 400 according to the present disclosure is illustrated.

[0012] Figure 5 A flow chart of a method for manufacturing a sensor device according to the present disclosure is illustrated.

[0013] Figure 6 A flow chart of a method for sensing current according to the present disclosure is illustrated. DETAILED DESCRIPTION

[0014] The sensor device 100 of FIG. 1 may include a conductive carrier 1 and a magnetic field sensor 4 mounted thereon. The magnetic field sensor 4 may include a first pair of sensing elements (or sensor elements) 6A, 6B and a second pair of sensing elements 8A, 8B. Optionally, the 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 arranged on (or mounted on) an electrical conductor 12, which may or may not be considered part of the sensor device 100.

[0015] As will be explained later, the magnetic field sensor 4 can be configured to provide a differential signal and can therefore be referred to as a differential magnetic field sensor. The differential sensing concept discussed herein can be configured to eliminate uniform 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 a magnetic field sensor integrated circuit or a magnetic field sensor chip. In the illustrated example, the upper main surface and the lower main surface of the magnetic field sensor 4 can be arranged in the xy plane.

[0016] The first sensing elements 6A and 6B may be separated from each other in a first direction, that is, a straight line connecting the first sensing 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 sensing elements 6A and 6B may be sensitive to a magnetic field in the x-direction. That is, each of the first sensing elements 6A and 6B may be configured to sense the x-component of the magnetic field present at the position of the corresponding sensing element. In the following, the first sensing elements 6A and 6B may also be referred to as the "left" sensing element and the "right" sensing element, respectively. It should be noted that due to Figure 1B In the selected coordinate system, the sensing element 6A on the left side may be labeled as the "right" sensing element 6A, and the sensing element 6B on the right side may be labeled as the "left" sensing element 6B. However, in another example the labeling of the sensing elements 6A and 6B may be chosen differently.

[0017] In a similar manner, the second sensing elements 8A and 8B can be separated from each other in a second direction substantially perpendicular to the first direction. That is, the straight line connecting the second sensing elements 8A and 8B can be parallel to the second direction. In the illustrated example, the second direction can correspond to the y direction. Each of the second sensing elements 8A and 8B can be sensitive to the magnetic field in the y direction. That is, each of the second sensing elements 8A and 8B can be configured to sense the y component of the magnetic field present at the position of the corresponding sensing element. In the following text, the second sensing elements 8A and 8B can also be referred to as the "upper" sensing element and the "lower" sensing element, respectively.

[0018] For example, the first sensing elements 6A, 6B and the second sensing elements 8A, 8B can be arranged in the xy plane, i.e., they can have equal z coordinates. In the illustrated case, the pitch (or distance) between the first sensing elements 6A and 6B can be substantially equal to the pitch between the second sensing elements 8A and 8B. Therefore, the four sensing elements 6A, 6B and 8A, 8B can be arranged on a circle. In another example, the pitch between the second sensing elements 8A and 8B can be increased or decreased, so that in such a case the four sensing elements 6A, 6B and 8A, 8B can be arranged on an ellipse.

[0019] In one example, each of the sensing elements 6A, 6B and the sensing elements 8A, 8B can be separately implemented as a resistor bridge, which can include an exemplary number of four resistors. In general, the magnetic field sensor 4 and its sensing elements 6A, 6B and 8A, 8B are not limited to a specific sensor technology. For example, the sensing elements 6A, 6B and 8A, 8B can be magnetoresistive xMR sensing elements (such as, for example, AMR sensing elements, GMR sensing elements, or TMR sensing elements). In this regard, the first sensing elements 6A, 6B and the second sensing elements 8A, 8B can correspond to in-plane magnetoresistive elements (or in-plane current (CIP) magnetoresistive elements). In other examples, the sensing elements 6A, 6B and 8A, 8B can be implemented as Hall sensing elements or fluxgate sensing elements.

[0020] The sensing elements 6A, 6B and 8A, 8B may be integrated into the circuit of the chip. Such 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 corresponding sensing elements, components for signal amplification and / or analog-to-digital conversion may also be considered as part of the sensing elements 6A, 6B and 8A, 8B or not be considered as part of the sensing elements 6A, 6B and 8A, 8B. It should be noted that the components of the chip may be combined with the components of the chip. Figure 2 More detailed implementations of exemplary circuit arrangements and sensing elements are shown and discussed.

[0021] The electrical conductor 12 is not limited to a specific type, shape or material, and may be, for example, one of a conductor track, a printed circuit board track, a busbar, a current track, etc. In the illustrated case, the electrical conductor 12 may exemplarily correspond to a conductor track arranged on the upper surface of a multilayer printed circuit board. The electrical conductor 12 of FIG. 1 (or a portion thereof) may have a substantially linear shape and may exemplarily extend in the y direction. In other examples, the electrical conductor 12 may have a different shape, such as, for example, in combination with the following description. Figure 4 The examples shown and discussed are of U-shape.

[0022] As from Figure 1B As can be seen in the top view of , the electrical conductor 12 and the sensor device 100 can be aligned relative to each other. In this regard, the edge of the electrical conductor 12 and the connecting line between the second sensing elements 8A and 8B can be aligned relative to each other. More specifically, the right edge of the electrical conductor 12 and the connecting line between the second sensing elements 8A and 8B can be consistent. In addition, the first sensing elements 6A and 6B can be arranged symmetrically relative to the right edge of the electrical conductor 12. That is, the shortest distance between the sensing element 6A and the right edge of the electrical conductor 12 can be substantially equal to the shortest distance between the sensing element 6B and the right edge of the electrical conductor 12. The straight line connecting the sensing elements 6A and 6B can be substantially perpendicular to the right edge of the electrical conductor 12.

[0023] The 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 a metal and / or a metal alloy (particularly at least one material of copper, copper alloy, nickel, iron-nickel, etc.). In the illustrated case, the lead frame 2 may exemplarily include a die pad 14 and two rows of leads (or pins or lead fingers) 16A, 16B arranged on opposite sides of the die pad 14. In another example, the number and arrangement of the die pad and the leads may be selected differently.

[0024] In the illustrated example, the die pad 14 may be arranged in an xy plane. The left and right edges of the die pad 14 may extend in the y direction, and the top and bottom edges of the die pad 14 may extend at least partially in the x direction. Figure 1B In the top view of the sensor 100, the center (or geometric center) of the magnetic field sensor 4 and the center (or geometric center) of the conductive carrier 2 (or the die pad 14) may be consistent. Each row of leads 16A and 16B may include a plurality of leads arranged in parallel, wherein 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 gull-wing shaped and the sensor device 100 may correspond to a surface mount device.

[0025] In the illustrated case, the magnetic field sensor 4 can be exemplarily arranged between the electrical conductor 12 and the conductive carrier 2. In particular, the magnetic field sensor 4 can be mounted on the bottom surface of the die pad 14, i.e. the magnetic field sensor 4 can be mounted in a bottom die configuration. In another example, the conductive carrier 14 can alternatively be arranged between the electrical conductor 2 and the magnetic field sensor 4. In particular, the magnetic field sensor 4 can then be mounted in a top die configuration, i.e. the magnetic field sensor 4 can be mounted on the upper surface of the die 14.

[0026] The sealing material 10 may include or may be made of at least one material in a molding compound, epoxy resin, filled epoxy resin, glass fiber filled epoxy resin, imide, thermoplastic, thermosetting polymer, polymer blend, laminate, etc. The encapsulation material 10 may be formed based on at least one molding in compression molding, injection molding, powder molding, liquid molding, map molding, laminate molding, etc. The encapsulation material 10 may be configured to protect the encapsulated device components from threats such as mechanical impact, chemical contamination, light exposure, etc. In the illustrated example, the encapsulation material 10 may form a body or encapsulation having two relative main surfaces extending in the xy plane. Due to such packaging, the sensor device 100 may also be referred to as a sensor package.

[0027] The conductive carrier 2, the magnetic field sensor 4 and the leads 16A, 16B may be at least partially encapsulated in the encapsulation material 10. In contrast, the electrical conductor 12 may be an external component of the package, i.e. it may be arranged outside the encapsulation material 10. Figure 1B In the top view of FIG. 1 , for illustrative purposes, the encapsulation material 10 is not shown so as not to obscure the device components embedded therein.

[0028] The electrical contacts 18 of the magnetic field sensor chip 4 can be electrically connected to one or more leads 16B via electrical connection elements 20. In the illustrated example, the electrical connection elements 20 can correspond to wires. In another example, the electrical connection elements 20 can include strips, clips, etc. Figure 1A As can be seen in the perspective view, leads 16A and 16B may at least partially protrude from the encapsulation material, so that encapsulated magnetic field sensor 4 is electrically accessible from outside encapsulation material 10 .

[0029] An exemplary operation of the sensor device 100 is described below. During this operation, a current may flow through the electrical conductor 12. The output signal of the sensor device 100 based on the measurement of the sensing elements 6A, 6B and 8A, 8B may be used to determine the amplitude of the current. In particular, the current may be time-varying and may, for example, include or correspond to a fast transient signal, a high frequency AC signal, a DC signal with ripple, etc. In the illustrated example, the electrical conductor 12 may extend in the y direction, so that the magnetic field generated by the current through the electrical conductor 12 may be located in the xz plane. Furthermore, in the case of a time-varying current, eddy currents may be induced in the conductive carrier 2, in particular in the die pad 14.

[0030] The first pair of first sensing elements 6A and 6B may be configured to provide a first differential signal based on the magnetic field sensed at the locations of the first sensing elements 6A and 6B, respectively. In particular, the first differential signal may correspond to the difference B Right -B Left , where B Right and B Left The (x-component) of the magnetic field sensed at the first sensing elements 6A and 6B may be labeled, respectively. The magnetic field at the location of the first sensing elements 6A and 6B may include a magnetic field generated by the current through the electrical conductor 12. In addition, the eddy currents induced in the conductive carrier 2 (or in the die pad 14) may generate a differential magnetic field at the location of the first sensing elements 6A and 6B, which overlaps with the magnetic field of the external conductor 12. Therefore, the first differential signal provided by the first sensing elements 6A and 6B may represent the magnetic field generated by the current through the electrical conductor 12 and the eddy currents generated in the conductive carrier 2.

[0031] In a similar manner, the second pair of second sensing 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 sensing elements 8A and 8B, respectively. In particular, the second differential signal may correspond to the difference B Up -B Down , where B Up and B Down The (y-component) of the magnetic field sensed at the second sensing elements 8A and 8B (or associated sensing signals) may be identified, respectively. The magnetic field generated by the current through the electrical conductor 12 may be located in the xz plane, but does not have a magnetic field component in the y direction. Due to their sensitivity in the y direction, the second sensing elements 8A and 8B may therefore not sense any magnetic field generated by the current through the electrical conductor 12. Therefore, the second differential signal provided by the second sensing elements 8A and 8B may represent the magnetic field generated by the eddy currents and may be independent of the magnetic field generated by the current through the electrical conductor 12.

[0032] As explained below, the first differential signal and the second differential signal can be used to provide an output signal that is independent of the magnetic field generated by the eddy currents. The output signal can represent the amplitude of the current through the electrical conductor 12. For this purpose, the sensor device 100 can include a unit that is configured to provide an output signal based on a difference or a sum including the first differential signal and the second differential signal. It should be noted that an exemplary circuit arrangement for providing the output signal will be shown and described in conjunction with FIG. 1 hereinafter.

[0033] The induced eddy currents may flow in a circular (or elliptical) shape in the conductive carrier 2, in particular in the xy plane of the die pad 14. Therefore, the magnetic field generated by the eddy currents may generate a differential magnetic field at the locations of the first sensing elements 6A, 6B and the second sensing elements 8A, 8B, respectively.

[0034] In the case of a rotationally symmetric conductive carrier (or lead frame) 2 (e.g. having a circular shape), the size of the differential magnetic field at the first pair of sensing elements 6A, 6B and the differential magnetic field at the second pair of sensing elements 8A, 8B may be substantially the same. Therefore, by obtaining the difference between the first differential signal and the second differential signal, the signal component generated by the eddy current may be eliminated. That is, the influence of the induced eddy current may be inherently suppressed, and the corresponding output signal V of the sensor device 100 may be out It is independent of the magnetic field generated by eddy currents. Output signal V out The current through the electrical conductor 12 can thus be represented. For the case of a rotationally symmetrical carrier 2, the output signal V out Can correspond to

[0035] V out = (B Right - B Left ) - (B Up - B Down ). (1)

[0036] In the case of a rotationally asymmetric conductive carrier (or lead frame) 2, the size of the differential magnetic field generated by the eddy currents at the location of the first pair of sensing elements 6A, 6B and at the location of the second pair of sensing elements 8A, 8B may not necessarily be the same. In this case, at least one of the first differential signal or the second differential signal is scaled before obtaining the difference or sum of the two differential signals. For example, one or both of the differential signals may be scaled by using one or two variable gain amplifiers providing a scaling factor, for example in combination with Figure 2 Generally speaking, the output signal V out Then it can correspond to

[0037] V out = GainS·(B Right- B Left ) - GainL·(B Up - B Down ), (2)

[0038] wherein GainS and GainL are scaling factors which may depend in particular on the geometry or shape of the conductive carrier 2. By this means, the compensation of the contribution of eddy currents may be adjusted to the specific geometry or shape of the conductive carrier 2.

[0039] In a more specific case, taking into account the geometry of the conductive carrier 2, only the scaling factor GainL for the second pair of sensing elements 8A and 8B may be considered, while the scaling factor GainS for the first pair of sensing elements 6A and 6B may be discarded (or set to a value of 1). The output signal Vout may then correspond to

[0040] V out = (B Right - B Left ) - GainL·(B Up - B Down ). (3)

[0041] As mentioned above, when determining the output signal V out When the sensitivity of the left sensing element 6B is reversed, the difference value B may be replaced by the corresponding sum of the signals. Right -B Left It may be necessary to Right +B Left Such sensitivity reversal may cause the sensed value B Left The sign of , which may then need to be taken into account accordingly, forms a sum instead of a difference. In a similar manner, one or more of the differences specified by equations (1) to (3) may be replaced by a corresponding sum if a change in the sensitivity of one or more of the included sensing elements may require such a replacement.

[0042] The sensor device according to the present disclosure may provide various technical effects as described below and may be superior to conventional sensor devices in various aspects.

[0043] As discussed above, the sensor device 100 can provide an inherent solution for compensating for the effects of the output signal caused by the induced eddy current. Due to the application of the compensation solution, the output signal of the sensor device 100 will not be degraded due to the presence of eddy currents. Therefore, compared to conventional sensor devices, a higher overall accuracy of the sensor device 100 can be provided.

[0044] In conventional sensor devices, eddy currents induced in a conductive carrier can be avoided by interrupting the current path of the eddy currents in the carrier. For this purpose, the conductive material of the carrier can be removed. For example, geometric features (such as cutouts, slits, notches or cavities) that are usually arranged close to the sensing element can avoid the formation of eddy currents. Such carrier modifications can be achieved by processing techniques (such as stamping, etching, laser cutting, etc.). In particular, special tools may be required, which may be time-consuming and may lead to an increase in overall manufacturing costs. In addition, the corresponding sensor device needs to be re-qualified whenever the standard geometry of the conductive carrier is replaced or modified.

[0045] In contrast, the sensor device according to the present disclosure can provide an intrinsic eddy current compensation solution without changing the geometry of the conductive carrier. Referring back to the example of FIG. 1 , the conductive carrier 2 (and in particular the die pad 14) of the sensor device 100 may not have any features configured to interrupt the current path of the eddy current. Compared to conventional sensor devices, the manufacture of the sensor device according to the present disclosure can therefore be less time-consuming and cheaper. In addition, conventional device requalification may become obsolete. Instead, the default sensor package and / or the standard geometry of the conductive carrier can be reused.

[0046] As discussed above in connection with equations (2) and (3), the use of scaling factors allows simple and fast adaptation of the eddy current compensation scheme to various device and carrier geometries.A sensor device according to the present disclosure may thus be implemented for a variety of device and carrier geometries.

[0047] The sensor device according to the present disclosure can be used in conjunction with many industrial and automation applications. In particular, the concepts described herein can be used in conjunction with any application that relies on high precision and fast input signals. In this regard, common applications can be, for example, high voltage eFuse, circuit breakers, etc. The sensor device described herein can be configured to be used in a system for detecting overcurrent events. In this context, the higher precision for measuring current can particularly avoid any unintentional activation of overcurrent detection.

[0048] Figure 2 The circuit arrangement 200 may be included in a sensor device according to the present disclosure, such as, for example, the sensor device 100 of FIG. 1 . For example, the elements of the circuit arrangement 200 may be integrated in the same semiconductor chip. The circuit arrangement 200 may include a first (upper) signal path 22A and a second (lower) signal path 22B. Referring back to the example of FIG. 1 , the circuit arrangement 200 may be configured to provide an output signal V as specified, for example, by any of equations (1) to (3) outIn this context, 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 a scaling factor that may depend on the shape of the conductive carrier 2 as described before.

[0049] The first signal path 22A may include a first pair of first sensing elements 6A and 6B, which may be supplied by a power supply voltage VDDS. For example, each of the first sensing elements 6A and 6B may include a bridge circuit (or resistor bridge). In the illustrated example, the corresponding bridge circuit may correspond to a Wheatstone bridge circuit including four resistors 24A to 24D. Each circuit in the Wheatstone bridge circuit may have a relative or antiparallel sensitivity direction in an independent branch of the bridge, as indicated by the arrows in the resistors 24A to 24D.

[0050] It should be noted that the implementation of the first sensing elements 6A and 6B is not limited to a particular design or type. In the illustrated example, the first sensing elements 6A and 6B may include two fully differential xMR bridges. In another example, the first sensing elements 6A and 6B may include a spatially distributed differential xMR bridge. In another example, the first sensing elements 6A and 6B may include one or more Hall sensing elements, which may be spatially distributed.

[0051] The first signal path 22A may further include a first amplifier 26A configured to provide a gain factor GainS. Figure 2 As exemplarily shown in , the first amplifier 26A can be interconnected with the first sensing elements 6A and 6B (or associated bridge circuits). In particular, the first (upper) input of the first gain amplifier 26A can be electrically coupled to a node 28A between two resistors 24A and 24D arranged in the first branch of the first bridge circuit, and to a node 28A between two resistors 24A and 24D arranged in the first branch of the second bridge circuit. In addition, the second (bottom) input of the first gain amplifier 26A can be electrically coupled to a node 28B between two resistors 24B and 24C arranged in the second branch of the first bridge circuit, and to a node 28B between two resistors 24B and 24C arranged in the second branch of the second bridge circuit.

[0052] Each of the first sensing elements 6A and 6B (or the associated bridge circuit) can be configured to provide a differential signal. For example, the differential signal can correspond to a differential (particularly analog) output voltage. The differential signals can be provided to the inputs of the first amplifier 26A, respectively. Referring back to the example of FIG. 1 , the output of the first amplifier 26A can correspond to a first differential signal, which represents the magnetic field generated by the current through the electrical conductor 12 and by the eddy currents generated in the conductive carrier 2. Note that the first amplifier 26A can be configured to amplify the first differential signal using an amplification factor GainS. That is, the output of the first amplifier 26A can be GainS·(B Right -B Left ). The output may correspond to a (particularly analog) output voltage.

[0053] like Figure 2 As can be seen in the exemplary block diagram of , the second signal path 22B can be at least partially similar to the first signal path 22A. The resistors 24A to 24D of the second sensing elements 8A and 8B can have different sensitivity orientations compared to the first sensing elements 6A and 6B of the first signal path 22A. In particular, the sensitivity directions of the resistors 24A to 24D in the second signal path 22B can be rotated 90 degrees counterclockwise compared to the resistors 24A to 24D of the first signal path 22A.

[0054] Each of the second sensing elements 8A and 8B (or the associated bridge circuits) may be configured to provide a differential signal. The differential signals may be provided to the inputs of the second amplifier 26B, respectively. Referring back to the example of FIG. 1 , the output of the second amplifier 26B may correspond to a second differential signal, which is representative of the magnetic field generated by the eddy currents and is independent of the magnetic field generated by the current through the electrical conductor 12. Note that the second amplifier 26B may be configured to amplify the second differential signal using an amplification factor GainL. Referring back to the example of FIG. 1 , the amplification factor GainL of the second amplifier 26B may in particular be based on the shape or geometry of the conductive carrier 2. The output of the second amplifier 26B may therefore be GainL·(B Up -B Down ). The output may correspond to a (particularly analog) output voltage.

[0055] The circuit arrangement 200 may further include a third amplifier 30. The output of the first amplifier 26A may be coupled to a first (upper) input of the third amplifier 30. In a similar manner, the output of the second amplifier 26B may be coupled to a second (bottom) input of the third amplifier 30. The third amplifier 30 may be configured to output the difference of the signals applied to its two inputs. For example, the output may correspond to a (particularly analog) output voltage. In the illustrated example, the output V of the third amplifier 30 is out Can be

[0056] V out = GainS·(B Right - B Left ) - GainL·(B Up - B Down ). (4)

[0057] Figure 3 includes FIG. 3A to FIG. 3C , which illustrates the output signals of various sensor devices. The illustrated output signals were obtained by using simulation software for calculating electric and magnetic fields. FIG. 3A to FIG. 3C Each of the figures includes a magnetic field sensor 4 relative to the right edge of the electrical conductor 12 (see, for example, Figure 1B ). In this aspect, an x ​​displacement of 0 μm is associated with Figure 1B In addition, for example, an x ​​displacement of +100 μm (-100 μm) is related to Figure 1B , in which the magnetic field sensor 4 is displaced by a distance of 100 μm in the positive (negative) x-direction. It should be noted that the x-displacement of the magnetic field sensor 4 in question may be undesirable and may occur in particular due to assembly tolerances.

[0058] Figure 3A The output signal of a sensor device comprising a non-conductive carrier is shown. Since eddy currents cannot occur in a non-conductive carrier, the output signal is independent of any influences that may have been generated in a similar device comprising a conductive carrier. In this respect, Figure 3A The situation can be regarded as an ideal state. The amplitude of the output signal B xRight -B xLeft Plotted against frequency (eg of a fast transient signal). Changes in the output signal at higher frequencies may simply be related to the skin effect of the outer electrical conductor 12 .

[0059] Figure 3B The output signal of a sensor device comprising an electrically conductive lead frame in which eddy currents can be induced is shown. The amplitude B of the output signal xRight -B xLeft Plotted against frequency (e.g. of a fast transient signal). Figure 3B It can be seen that eddy currents induced in the lead frame can cause significant amplification at higher frequencies, which may cause reduced accuracy of the measurement signal and potential fault activation of overcurrent detection.

[0060] Figure 3C The output signal of a sensor device comprising a conductive lead frame is shown, in which eddy currents may occur but can be compensated based on the compensation scheme as described above. An exemplary scaling factor GainL of 3.5 is applied. Figure 3Aand Figure 3C The benefits of the applied compensation scheme become apparent when compared to the scenario with Figure 3C In this case, the influence of eddy currents induced in the lead frame can be greatly reduced.

[0061] Figure 4 The sensor device 400 of FIG. 1 may include some or all of the features of the sensor device 100 of FIG. 1 . All comments made in conjunction with the previously described examples may also apply to Figure 4 The operation of sensor device 400 may be similar to the operation of the aforementioned sensor device.

[0062] Compared with the example in Figure 1, Figure 4 The electrical conductor 12 can have different shapes. Figure 4 In a top view of , the electrical conductor 12 may substantially have a rectangular shape including two notches 32A and 32B and a third notch 32C, wherein the notches 32A and 32B extend from an upper edge of the electrical conductor 12 in the negative y direction, and the third notch 32C extends from a bottom edge of the electrical conductor 12 in the positive y direction.

[0063] In the area between the two notches 32A and 32B, the electrical conductor 12 may include a u-shaped portion. The u-shaped portion of the electrical conductor 12 may include a first section, which is arranged on the left side and extends in the y direction, and a second section, which is arranged on the right side and extends in the y direction. In addition, the u-shaped portion of the electrical conductor 12 may include a third section, which extends in the x direction and connects the first section and the second section.

[0064] The u-shaped portion of the electrical conductor 12 and the sensor device 400 can be aligned relative to each other. In this aspect, the sensing element 6A of the first pair of sensing elements 6A, 6B can be arranged on the first section of the u-shaped portion, and the second sensing element 6B of the first pair of sensing elements 6A, 6B can be arranged on the second section of the u-shaped portion. In addition, the second pair of sensing elements 8A and 8B can be arranged between the first section and the second section of the u-shaped portion, i.e., they can be arranged on the third notch 32C.

[0065] Figure 5 A flow chart of a method for manufacturing a sensor device according to the present disclosure is illustrated. The method can be used to manufacture any of the aforementioned sensor devices and can therefore be read in conjunction with the foregoing figures. The following description uses the reference numerals of the aforementioned examples. The method is illustrated in a general manner in order to qualitatively specify aspects of the present disclosure. The method can be extended by one or more aspects described in conjunction with other examples.

[0066] At 34, the magnetic field sensor 4 can be produced. Producing the magnetic field sensor 4 can include an act 34a, which produces a first pair of first sensing elements 6A and 6B configured to provide a first differential signal, wherein the first sensing elements 6A and 6B are separated from each other in a first direction, and wherein each of the first sensing elements 6A and 6B is sensitive to a magnetic field in the first direction. Producing the magnetic field sensor 4 can further include an act 34b, which produces a second pair of second sensing elements 8A and 8B configured to provide a second differential signal, wherein the second sensing elements 8A and 8B are separated from each other in a second direction perpendicular to the first direction, and wherein each of the second sensing elements 8A and 8B is sensitive to a magnetic field in the second direction. Producing the magnetic field sensor 4 can further include an act 34c, which produces 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, a conductive carrier 2 can be provided. At 38, the magnetic field sensor 4 can be mounted on the conductive carrier 2.

[0067] Figure 6 A flow chart of a method according to the present disclosure is illustrated. The method may be performed by any of the aforementioned sensor devices and may therefore be read in conjunction with the aforementioned figures. The following description uses the reference numerals of the aforementioned examples. The method may be applied to sensing a current through an electrical conductor 12 by a magnetic field sensor 4 mounted on a conductive carrier 2. The method is illustrated in a general manner in order to qualitatively specify aspects of the present disclosure. The method may be extended by one or more aspects described in conjunction with the other examples.

[0068] At 40, a first differential signal is representative of a magnetic field generated by the current through the electrical conductor 12 and by eddy currents generated in the conductive carrier 2, which magnetic field can be sensed by a first pair of first sensing elements 6A and 6B of the magnetic field sensor 4. At 42, a second differential signal is representative of a magnetic field generated by the eddy currents and is independent of a magnetic field generated by the current through the electrical conductor 12, which magnetic field can be sensed by a second pair of second sensing elements 8A and 8B of the magnetic field sensor 4. At 44, an output signal can be provided based on a difference or a sum including the first differential signal and the second differential signal.

[0069] Example

[0070] A sensor device, a method for manufacturing a sensor device and a method for sensing an electric current are explained below by way of example.

[0071] Example 1 is a sensor device, comprising: a conductive carrier; a magnetic field sensor mounted on the conductive carrier, wherein the magnetic field sensor comprises: a first pair of first sensing elements and a second pair of second sensing elements, the first pair of first sensing elements being configured to provide a first differential signal, the first differential signal representing a magnetic field generated by a current passing through an electrical conductor and by eddy currents generated in the conductive carrier, the second pair of second sensing elements being configured to provide a second differential signal, the second differential signal representing a magnetic field generated by the eddy currents and being independent of the magnetic field generated by the current passing through the electrical conductor; and a unit configured to provide an output signal based on a difference or a sum of the first differential signal and the second differential signal.

[0072] 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.

[0073] Example 3 is a sensor device according to Example 1 or 2, wherein: the first sensing elements are separated from each other in a first direction, and each of the first sensing elements is sensitive to a magnetic field in the first direction, and the second sensing elements are separated from each other in a second direction perpendicular to the first direction, and each of the second sensing elements is sensitive to a magnetic field in the second direction.

[0074] Example 4 is a sensor device according to Example 3, wherein the electrical conductor extends in the second direction.

[0075] Example 5 is the sensor device according to example 3 or 4, wherein the edge of the electrical conductor and the connection line between the second sensing elements are coincident when viewed in a third direction perpendicular to the first direction and the second direction.

[0076] Example 6 is the sensor device according to Example 5, wherein the first sensing element is arranged symmetrically with respect to an edge of the electrical conductor.

[0077] Example 7 is the sensor device according to Example 3, wherein the electrical conductor comprises a u-shaped electrical conductor.

[0078] Example 8 is a sensor device according to Example 7, wherein the u-shaped electrical conductor includes: a first segment and a second segment extending in the second direction, and a third segment extending in the first direction, the third segment connecting the first segment and the second segment.

[0079] Example 9 is a sensor device according to Example 8, wherein, when viewed in a third direction perpendicular to the first direction and the second direction: the first sensing element of the first pair of sensing elements is arranged above the first segment, and the second sensing element of the first pair of sensing elements is arranged above the second segment, and the second pair of sensing elements is arranged between the first segment and the second segment.

[0080] Example 10 is the sensor device of any of Examples 3 to 9, wherein the conductive carrier is arranged in a plane defined by the first direction and the second direction.

[0081] Example 11 is the sensor device according to any one of Examples 3 to 10, wherein a center of the magnetic field sensor and a center of the conductive carrier are coincident when viewed in a third direction perpendicular to the first direction and the second direction.

[0082] 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 an amplification factor of the amplifier is based on a shape of the conductive carrier.

[0083] Example 13 is a sensor device according to any of the preceding examples, wherein: the first of the second sensing elements includes a first bridge circuit including a first branch and a second branch, the second of the second sensing elements includes a second bridge circuit including a first branch and a second branch, a first input of the gain amplifier is electrically coupled to a node between two resistors arranged in the first branch of the first bridge circuit and is electrically coupled to a node between two resistors arranged in the first branch of the second bridge circuit, and a second input of the gain amplifier is electrically coupled to a node between two resistors arranged in the second branch of the first bridge circuit and is electrically coupled to a node between two resistors arranged in the second branch of the second bridge circuit.

[0084] Example 14 is the sensor device according to any of the preceding examples, wherein the magnetic field sensor is arranged between the electrical conductor and the conductive carrier.

[0085] Example 15 is the sensor device of any of the preceding examples, wherein the conductive carrier does not have any features configured to interrupt a current path of eddy currents.

[0086] Example 16 is a sensor device according to any of the preceding examples, wherein: the magnetic field sensor is encapsulated in an encapsulation material, and the electrical conductor is arranged outside the encapsulation material.

[0087] Example 17 is a sensor device according to any of the preceding examples, wherein the sensor device is configured for use in a system for detecting an overcurrent event.

[0088] Example 18 is a sensor device comprising: a conductive carrier; a magnetic field sensor mounted on the conductive carrier, wherein the magnetic field sensor comprises: a first pair of first sensing elements configured to provide a first differential signal, wherein the first sensing elements are separated from each other in a first direction, and wherein each of the first sensing elements is sensitive to a magnetic field in the first direction, and a second pair of second sensing elements configured to provide a second differential signal, wherein the second sensing elements are separated from each other in a second direction perpendicular to the first direction, and wherein each of the second sensing elements is sensitive to a magnetic field in the second direction; and a unit configured to provide an output signal based on a difference or a sum of the first differential signal and the second differential signal.

[0089] Example 19 is a sensor device according to Example 18, wherein: the first differential signal represents a magnetic field generated by the current through the electrical conductor and by eddy currents generated in the conductive carrier, and the second differential signal represents the magnetic field generated by the eddy currents and is independent of the magnetic field generated by the current through the electrical conductor, and the output signal is independent of the magnetic field generated by the eddy currents.

[0090] Example 20 is the sensor device according to example 18 or 19, wherein the first sensing element and the second sensing element are arranged on a circle or an ellipse.

[0091] Example 21 is a sensor device according to any of Examples 18 to 20, wherein the first sensing element and the second sensing element are in-plane magnetoresistive elements.

[0092] Example 22 is a method for sensing current passing through an electrical conductor by a magnetic field sensor mounted on a conductive carrier, the method comprising: sensing a first differential signal by a first pair of first sensing elements of the magnetic field sensor, the first differential signal representing a magnetic field generated by the current passing through the electrical conductor and by eddy currents generated in the conductive carrier; sensing a second differential signal by a second pair of second sensing elements of the magnetic field sensor, the second differential signal representing a magnetic field generated by the eddy currents and being independent of the magnetic field generated by the current passing through the electrical conductor; and providing an output signal based on a difference or a sum of the first differential signal and the second differential signal.

[0093] Example 23 is a method for manufacturing a sensor device, the method comprising: producing a magnetic field sensor, wherein producing the magnetic field sensor comprises: producing a first pair of first sensing elements, which are configured to provide a first differential signal, wherein the first sensing elements are separated from each other in a first direction, and wherein each of the first sensing elements is sensitive to a magnetic field in the first direction, and producing a second pair of second sensing elements, which are configured to provide a second differential signal, wherein the second sensing elements are separated from each other in a second direction perpendicular to the first direction, and wherein each of the second sensing elements is sensitive to a magnetic field in the second direction; producing a unit, which is configured to provide an output signal based on a difference or a sum of the first differential signal and the second differential signal; providing a conductive carrier; and mounting the magnetic field sensor on the conductive carrier.

[0094] Although the present disclosure has been described with reference to illustrative examples, this description is not intended to be interpreted in a limiting sense. Various modifications and combinations of the illustrative examples and other examples of the present disclosure will be apparent to those skilled in the art when referring to this description. Therefore, the appended claims are intended to cover any such modifications or examples.

Claims

1. A sensor device, comprising: A conductive carrier (2); A magnetic field sensor (4) is mounted on the conductive carrier (2), wherein the magnetic field sensor (4) comprises: a first pair of first sensing elements (6A, 6B) configured to provide a first differential signal representative of a magnetic field generated by a current through an electrical conductor (12) and by eddy currents generated in the conductive carrier (2), and a second pair of second sensing 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 current through the electrical conductor (12); as well as A unit is configured to provide an output signal based on a difference or a sum of the first differential signal and the second differential signal. 2 . The sensor device of claim 1 , wherein the output signal is independent of the magnetic field generated by the eddy currents.

3. The sensor device according to claim 1 or 2, wherein: The first sensing elements (6A, 6B) are separated from each other in a first direction, and each of the first sensing elements (6A, 6B) is sensitive to a magnetic field in the first direction, and The second sensing elements (8A, 8B) are separated from each other in a second direction perpendicular to the first direction, and each of the second sensing elements (8A, 8B) is sensitive to a magnetic field in the second direction.

4. The sensor device according to claim 3, wherein the electrical conductor (12) extends in the second direction.

5. The sensor device according to claim 3 or 4, wherein an edge of the electrical conductor (12) and a connection line between the second sensing elements (8A, 8B) are coincident when viewed in a third direction perpendicular to the first and second directions.

6. The sensor device according to claim 5, wherein the first sensing elements (6A, 6B) are arranged symmetrically with respect to the edge of the electrical conductor (12).

7. The sensor device according to claim 3, wherein the electrical conductor (12) comprises a u-shaped electrical conductor.

8. The sensor device of claim 7, wherein the u-shaped electrical conductor comprises: a first section and a second section extending in the second direction, and The third section extends in the first direction and connects the first section and the second section.

9. The sensor device according to claim 8, wherein when viewed in a third direction perpendicular to the first direction and the second direction: The first sensing element (6A) of the first pair of sensing elements (6A, 6B) is arranged on the first section, and the second sensing element (6B) of the first pair of sensing elements (6A, 6B) is arranged on the second section, and The second pair of sensing elements (8A, 8B) is arranged between the first section and the second section.

10. The sensor device according to any one of claims 3 to 9, wherein the electrically conductive carrier (2) is arranged in a plane defined by the first direction and the second direction.

11. The sensor device according to any one of claims 3 to 10, wherein a center of the magnetic field sensor (4) and a center of the conductive carrier (2) are coincident when viewed in a third direction perpendicular to the first direction and the second direction.

12. The sensor device according to any one of the preceding claims, further comprising: An amplifier (26B) is configured to amplify the second differential signal, wherein an amplification factor of the amplifier (26B) is based on the shape of the conductive carrier (2).

13. A sensor device according to any one of the preceding claims, wherein: A first one of the second sensing elements (8A, 8B) comprises a first bridge circuit, the first bridge circuit comprising a first branch and a second branch, A second one of the second sensing elements (8A, 8B) comprises a second bridge circuit, the second bridge circuit comprising a first branch and a second branch, a first input of the gain amplifier (26B) being electrically coupled to a node (28A) between two resistors (24A, 24D) arranged in the first branch of the first bridge circuit and to a node (28A) between two resistors (24A, 24D) arranged in the first branch of the second bridge circuit, and A second input of the gain amplifier (26B) is electrically coupled to a node (28B) between two resistors (24B, 24C) arranged in the second branch of the first bridge circuit, and is electrically coupled to a node (28B) between two resistors (24B, 24C) arranged in the second branch of the second bridge circuit.

14. The sensor device according to any of the preceding claims, wherein the magnetic field sensor (4) is arranged between the electrical conductor (12) and the electrically conductive carrier (2).

15. The sensor device according to any of the preceding claims, wherein the electrically conductive carrier (2) does not have any features configured to interrupt the current path of the eddy currents.

16. A sensor device according to any 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 outside the encapsulation material (10).

17. The sensor device of any of the preceding claims, wherein the sensor device is configured for use in a system for detecting overcurrent events.

18. A sensor device comprising: A conductive carrier (2); A magnetic field sensor (4) is mounted on the conductive carrier (2), wherein the magnetic field sensor (4) comprises: a first pair of first sensing elements (6A, 6B) configured to provide a first differential signal, wherein the first sensing elements (6A, 6B) are separated from each other in a first direction, and wherein each of the first sensing elements (6A, 6B) is sensitive to a magnetic field in the first direction, and a second pair of second sensing elements (8A, 8B) configured to provide a second differential signal, wherein the second sensing elements (8A, 8B) are separated from each other in a second direction perpendicular to the first direction, and wherein each of the second sensing elements (8A, 8B) is sensitive to a magnetic field in the second direction; as well as A unit is configured to provide an output signal based on a difference or a sum of the first differential signal and the second differential signal.

19. The sensor device of claim 18, wherein: The first differential signal is representative of a magnetic field generated by a current through an electrical conductor (12) and by eddy currents generated in the conductive carrier (2), 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 current through the electrical conductor (12), and The output signal is independent of the magnetic field generated by the eddy currents.

20. The sensor device according to claim 18 or 19, wherein the first sensing elements (6A, 6B) and the second sensing elements (8A, 8B) are arranged on a circle or an ellipse.

21. The sensor device according to any one of claims 18 to 20, wherein the first sensing element (6A, 6B) and the second sensing element (8A, 8B) are in-plane magnetoresistive elements.

22. A method for sensing a current through an electrical conductor (12) by a magnetic field sensor (4) mounted on a conductive carrier (2), the method comprising: sensing a first differential signal by a first pair of first sensing elements (6A, 6B) of the magnetic field sensor (4), the first differential signal being representative of a magnetic field generated by the current through the electrical conductor (12) and by eddy currents generated in the conductive carrier (2); sensing a second differential signal by a second pair of second sensing elements (8A, 8B) of the magnetic field sensor (4), the second differential signal being representative of a magnetic field generated by the eddy currents and being independent of a magnetic field generated by the current through the electrical conductor (12); as well as An output signal is provided based on a difference or a sum of the first differential signal and the second differential signal.

23. A method for manufacturing a sensor device, the method comprising: Producing a magnetic field sensor (4), wherein producing the magnetic field sensor (4) comprises: producing a first pair of first sensing elements (6A, 6B) configured to provide a first differential signal, wherein the first sensing elements (6A, 6B) are separated from each other in a first direction, and wherein each of the first sensing elements (6A, 6B) is sensitive to a magnetic field in the first direction, and producing a second pair of second sensing elements (8A, 8B) configured to provide a second differential signal, wherein the second sensing elements (8A, 8B) are separated from each other in a second direction perpendicular to the first direction, and wherein each of the second sensing elements (8A, 8B) is sensitive to a magnetic field in the second direction; a production unit configured to provide an output signal based on a difference or a sum of the first differential signal and the second differential signal; providing a conductive carrier (2); and The magnetic field sensor (4) is mounted on the conductive carrier (2).

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