Hall sensor and method for operating such a sensor

Abstract

Method for operating a Hall sensor (1) comprising the following steps: a) Providing a Hall sensor (1) comprising a Hall sensor element (2) with multiple spaced connection points (3A, 3B, 3C, 3D) and providing a current or voltage supply source (7) having supply terminals (6A, 6B) for outputting a supply current or supply voltage, b) Connecting a first terminal (3A) of the Hall sensor element (2) to a first supply terminal (6A) and connecting a second terminal (3B) of the Hall sensor element (2) to a second supply terminal (6B) at ground potential in order to apply the supply voltage to the Hall sensor element (2) or to pass the supply current through the Hall sensor element (2), characterized by the following further steps: c) Providing a lower reference value (T1) and an upper reference value (T2) for a voltage applied to a third terminal (3C) of the Hall sensor element (2) measured against ground potential, d) Recording an initial voltage value for this voltage, e) Comparing the first voltage value with the lower reference value (T1) and the upper reference value (T2), f) Generating an error signal depending on the results of these comparisons.

Description

[0001] The invention relates to a method for operating a Hall sensor according to the preamble of claim 1 and a Hall sensor according to the preamble of claim 6.

[0002] Such a procedure is known from DE 102 04 427 B4. It comprises the following steps: a) Providing a Hall sensor having a Hall sensor element with multiple spaced connection points, and providing a power supply source having supply terminals for outputting a supply current, b) Connecting a first terminal of the Hall sensor element to a first supply terminal and connecting a second terminal of the Hall sensor element to a second supply terminal at ground potential in order to pass the supply current through the Hall sensor element.

[0003] DE 102 04 427 B4 further discloses a Hall sensor with a Hall sensor element having several spaced-apart connection points, and a power supply source having a first and a second supply connection for outputting a supply current or a supply voltage, wherein the first supply connection for supplying a current to the Hall sensor element is connected to a first connection point of the Hall sensor element and the second supply connection is connected to a second connection point of the Hall sensor element. The Hall sensor is operated according to the spinning Hall principle, i.e., the direction of the supply current flowing through the Hall sensor element is changed periodically.In order to compensate for the dynamic error signals occurring in the Hall voltages, the Hall voltages tapped at the paired terminals opposite each other during switching in a first direction of rotation are summed and / or averaged with the Hall voltages tapped at the terminals during switching in a second direction of rotation.

[0004] From DE 10 2006 057 385 A1, a method for checking the measurement accuracy of at least one Hall sensor is also known, which has an electrical circuit into which at least two different measurement characteristics can be programmed. The method comprises the following steps: a) Providing a Hall sensor having a Hall sensor element with multiple spaced-apart connection points, and providing a voltage supply source having supply terminals for outputting a supply voltage, b) Connecting a first terminal of the Hall sensor element to a first supply terminal and connecting a second terminal of the Hall sensor element to a second supply terminal to apply the supply voltage to the Hall sensor element.

[0005] The Hall sensor element is placed in a predetermined magnetic field, which is generated by an excitation coil. From the Hall voltage measured by the sensor element and the measurement characteristic stored in the electrical circuit, the Hall sensor calculates a measurement value for the magnetic flux density of the magnetic field. This measurement value is then read into a test device connected to the Hall sensor. The test device compares the measurement value to a reference range. If a deviation occurs between the measurement value and the reference range, the Hall sensor's measurement characteristic is modified to reduce the deviation. If the measurement value does not match the reference range, even after repeated modifications of the measurement characteristic, the Hall sensor is marked as faulty.

[0006] From DE 102 04 427 B4, a Hall sensor is also known with an approximately plate-shaped Hall sensor element that has several connection points spaced apart from each other in the circumferential direction at its edge. The connection points are offset at uniform angular intervals with respect to a center such that two connection points are diametrically opposed to each other. When an excitation current is fed into the Hall sensor element by connecting two diametrically opposed connection points to the supply terminals of a current or voltage supply source, and the Hall sensor element is penetrated by a magnetic flux density perpendicular to its plate plane, the Lorentz force acts on the moving electrons of the current, deflecting the electrons perpendicular to their direction of motion in the plate plane.This creates an electric field perpendicular to the current direction in the Hall sensor element, which can be measured as an electrical voltage between the connection points that are not connected to the power supply terminals. This voltage is called the Hall voltage.

[0007] In practical applications of Hall sensors, however, the Hall voltage is superimposed by an undesired offset voltage. Hall sensor elements are typically manufactured as an integrated circuit together with the power supply and signal processing electronics, and mounted on a chip substrate and in a plastic housing. Due to manufacturing tolerances and during assembly, mechanical stresses can occur in the semiconductor crystal, which can cause the offset voltage.

[0008] To compensate for the offset voltages, the so-called spinning Hall principle is used in the method known from DE 102 04 427 B4. In this process, the excitation current is passed through the Hall sensor element in different directions, and the average of the measured voltages is calculated.

[0009] Although the Hall sensor and the method known from DE 102 04 427 B4 have proven their worth in numerous practical applications, there is still room for improvement. For example, the ever-increasing number of Hall sensors installed in motor vehicles has raised the demands on their reliability. The failure of just one Hall sensor can lead to a malfunction in the vehicle if the fault is not detected and, if necessary, compensated for by appropriate measures.

[0010] The task is therefore to create a Hall sensor of the type mentioned above and a method for operating a Hall sensor of the type mentioned above, which make it possible to easily detect and display any errors that may occur during the operation of the Hall sensor.

[0011] This problem is solved with respect to the method with the features of claim 1. In addition to the steps a) and b) mentioned above, these provide for the following further steps: c) Providing a lower reference value and an upper reference value for a voltage applied to a third terminal of the Hall sensor element, measured against ground potential, d) Recording an initial voltage value for this voltage, e) Comparing the first voltage value with the lower reference value and the upper reference value, f) Generating an error signal depending on the results of these comparisons.

[0012] Advantageously, an error signal is generated if the voltage at the third terminal lies outside a predetermined range and is therefore implausible. It is assumed that the voltage at the third terminal is primarily influenced by the voltage applied by the supply source between the first and second terminals, or by the excitation current conducted through the Hall sensor element via this terminal, and that the influence of the Hall voltage on the first voltage value is only minor. The difference between the lower and upper reference values ​​is therefore chosen to be larger than the highest Hall voltage that would normally be expected.

[0013] The error signal is generated in particular if the electrical connection between the third connection point and a measuring device used to detect the first voltage value is disturbed, for example if it has an open circuit and / or a short circuit to a line carrying a different potential and / or if the excitation current is not passed through the Hall sensor element or is passed through it with an incorrect current.

[0014] In a preferred embodiment of the invention, the following further steps are carried out: a) Detecting a second voltage value measured against ground potential for a voltage applied to a fourth terminal of the Hall sensor element, b) Comparing the second voltage value with the lower reference value and the upper reference value, c) Generating the error signal depending on the results of these comparisons.

[0015] This additional measure makes it possible to determine, in particular, if the electrical connection between the fourth connection point and a measuring device used to record the second voltage value is disrupted, for example because the connection has an open circuit and / or a short circuit to a line carrying a different potential.

[0016] In an advantageous embodiment of the invention, the following further steps are carried out: a) Detecting a third voltage value measured against ground potential for a voltage applied to the first terminal of the Hall sensor element, b) Comparing the third voltage value with the lower reference value and the upper reference value, c) Generating the error signal depending on the results of these comparisons.

[0017] The fault signal is therefore also activated if the potential applied from the supply source to the first connection point has an impermissible value.

[0018] In a preferred embodiment of the invention, the following further steps are carried out: a) Detecting a fourth voltage value measured against ground potential for a voltage applied to a second terminal of the Hall sensor element, b) Comparing the fourth voltage value with the lower reference value and the upper reference value, c) Generating the error signal depending on the results of these comparisons.

[0019] The fault signal is therefore also activated if the potential applied from the supply source to the second connection point has an impermissible value.

[0020] In a preferred embodiment of the method, the process steps b), d), e), and f) mentioned in claim 1, and optionally the process steps mentioned in claim 2 and / or claim 3 and / or claim 4, are repeated several times, wherein, in the second and optionally each subsequent iteration, the connection points of the Hall sensor element are preferably cyclically interchanged. The number of iterations is preferably at least as large as the number of connection points of the Hall sensor. It is even possible to acquire the first, second, third, and / or fourth voltage values ​​with offset compensation, i.e., to subtract any offset voltages contained therein. However, it is also conceivable to disregard offset compensation when acquiring these voltage values.

[0021] In the method according to the invention, the voltage between the third and fourth terminals of the Hall sensor element can be measured in a manner known per se in order to determine the Hall voltage. The spinning Hall principle is preferably used in the measurement of the Hall voltage to compensate for any offset voltages contained in the measurement signal.

[0022] The aforementioned problem is solved with respect to the Hall sensor of the type mentioned above by the fact that the Hall sensor has a first comparator unit which has a first input connected to a third terminal of the Hall sensor element, a second input connected to a reference signal generator for an upper reference value signal and an output for a first comparator signal, that the Hall sensor has a second comparator unit which has a third input connected to the third terminal, a fourth input connected to a reference signal generator for a lower reference value signal and an output for a second comparator signal, and that the outputs of the first and second comparator units are connected to an evaluation unit for generating an error signal dependent on the first and second comparator signals.

[0023] Thus, the Hall sensor enables the generation of an error signal if the voltage at the third terminal lies outside a range defined by the reference signal and is therefore implausible. It is assumed that the voltage at the third terminal is primarily influenced by the voltage applied by the power supply between the first and second terminals, or by the excitation current conducted through the Hall sensor element via this terminal, and that the influence of the Hall voltage on the first voltage value is negligible.The error signal can be generated in particular if the electrical connection between the third connection point and a measuring device used to detect the first voltage value is disturbed, for example if it has an open circuit and / or a short circuit to a line carrying a different potential and / or if the excitation current is not passed through the Hall sensor element due to a fault or is passed through it with an incorrect current.

[0024] In a preferred embodiment of the invention, the Hall sensor has a third comparator unit, which has a fifth input connected to the fourth terminal, a sixth input connected to the reference signal generator for the upper reference value signal, and an output for a third comparator signal; the Hall sensor has a fourth comparator unit, which has a seventh input connected to the fourth terminal, an eighth input connected to the reference signal generator for the lower reference value signal, and an output for a fourth comparator signal; and the outputs of the third and fourth comparator units are connected to the evaluation unit, and the evaluation unit is designed such that the error signal also depends on the third and fourth comparator signals.This means that the error signal can also be generated if the electrical connection between the fourth terminal and the fifth and / or seventh input is disrupted, for example, if it has an open circuit and / or a short circuit to a line carrying a different potential.

[0025] In an advantageous embodiment of the invention, the Hall sensor has a fifth comparator unit, which has a ninth input connected to the first terminal, a tenth input connected to the reference signal generator for the upper reference value signal, and an output for a fifth comparator signal; the Hall sensor has a sixth comparator unit, which has an eleventh input connected to the first terminal, a twelfth input connected to the reference signal generator for the lower reference value signal, and an output for a sixth comparator signal; and the evaluation unit is designed such that the error signal also depends on the fifth and sixth comparator signals.This means that the error signal can also be generated if the potential applied from the supply source to the first connection point has an impermissible value, and thus an excitation current with an incorrect value is passed through the Hall sensor element, or even no excitation current at all is passed through the Hall sensor element.

[0026] In a preferred embodiment of the invention, the Hall sensor has a seventh comparator unit, which has a thirteenth input connected to the second terminal, a fourteenth input connected to the reference signal generator for the upper reference value signal, and an output for a seventh comparator signal; the Hall sensor has an eighth comparator unit, which has a fifteenth input connected to the second terminal, a sixteenth input connected to the reference signal generator for the lower reference value signal, and an output for an eighth comparator signal; and the evaluation unit is designed such that the error signal also depends on the seventh and eighth comparator signals.This measure can also detect errors in the supply of excitation current to the Hall sensor element, for example, if no excitation current is passed through the Hall sensor element due to a contact fault between one supply connection and the second connection point.

[0027] In a further development of the invention, the Hall sensor has a switching device connected to the supply source and in control communication with a control unit, which is designed in such a way that a) that in a first operating state - the first and third entrances with the third connection point, - the fifth and seventh entrances with the fourth connection point, - the ninth and eleventh entrances with the first connection point, - the thirteenth and fifteenth entrances are connected to the second junction, b) that in a second operating state - the first and third entrances with the fourth connection point, - the fifth and seventh entrances with the first connection point, - the ninth and eleventh entrances with the second connection point, - the thirteenth and fifteenth entrances are connected to the third junction, c) that in a third operating state - the first and third entrances with the first connection point, - the fifth and seventh entrances with the second connection point, - the ninth and eleventh entrances with the third connection point, - the thirteenth and fifteenth entrances are connected to the fourth junction, and d) that in a fourth operating state - the first and third entrances with the second connection point, - the fifth and seventh entrances with the third connection point, - the ninth and eleventh entrances with the fourth connection point, - the thirteenth and fifteenth inputs are connected to the fifth terminal, and that the second, sixth, tenth and fourteenth inputs are each connected to the reference generator for the upper reference signal and the fourth, eighth, twelfth and sixteenth inputs are each connected to the reference generator for the lower reference signal.

[0028] To measure the Hall voltage that occurs when a magnetic flux density passes through the Hall sensor element, the Hall sensor can have a measuring device with which an electrical voltage applied between the third and fourth terminals can be measured. The Hall sensor preferably operates according to the spinning Hall principle in order to compensate for any unwanted offset voltages superimposed on the Hall voltage.

[0029] It should also be mentioned that in both the inventive method and the inventive Hall sensor, the Hall sensor element can be configured as a vertical or a horizontal Hall sensor element. A vertical Hall sensor element is understood to be a Hall sensor element that is sensitive to magnetic flux densities arranged parallel to the surface of the semiconductor chip. A horizontal or lateral Hall sensor element is understood to be a Hall sensor element that is sensitive to magnetic flux densities arranged perpendicular to the surface of the semiconductor chip.

[0030] Exemplary embodiments of the invention are explained in more detail below with reference to the drawing. It shows: Fig. 1 a block diagram of a Hall sensor operating according to the spinning Hall principle, Fig. 2 a graphical representation of the electrical voltages measured against ground potential at the connection points of a Hall sensor element of the Hall sensor, Fig. 3 a table listing electrical voltages applied to connection points C1, C2, C3, C4 of the Hall sensor element, Fig. 4 a representation similar Fig. 2, in which tolerance bands and reference values ​​T1, T2 are shown, Fig. 5 a block diagram of a Hall sensor operating according to the spinning Hall principle, which has a monitoring device by means of which it can be checked whether the electrical voltages at connection points C1, C2, C3, C4 of the Hall sensor element are within the tolerance bands provided for this purpose, Fig. 6 a table comparing the voltages present at the terminals C1, C2, C3, C4 of the Hall sensor element when the Hall sensor is functioning correctly with the reference values ​​T1, T2, and Fig. 7 a representation similar Fig. 6, however, where the table values ​​given are logical signal levels generated using comparators.

[0031] A in Fig. 1 Hall sensor, designated as a whole by 1, comprises a semiconductor chip into which a plate-shaped Hall sensor element 2 is integrated. The Hall sensor element 2 consists of a semiconductor material, such as silicon, and has several spaced-apart connection points 3A, 3B, 3C, 3D at its edge, which are offset from each other by 90° with respect to an imaginary central axis that is arranged orthogonally to the plane spanned by the Hall sensor element 2 and passes through a center of symmetry 4.

[0032] Terminals 3A, 3B, 3C, and 3D are connected to a switching device that has one multiplexer 5A, 5B, 5C, and 5D for each terminal 3A, 3B, 3C, and 3D, respectively. One output terminal of each multiplexer 5A, 5B, 5C, and 5D is connected to its corresponding terminal 3A, 3B, 3C, and 3D. Each multiplexer 5A, 5B, 5C, and 5D has two inputs connected to supply terminals 6A and 6B of a current or voltage supply source 7. This supply voltage V is provided by the supply source 7. B It serves to feed an excitation current into the Hall sensor element 2.

[0033] In a first phase of the current supply, a first supply connection 6A is connected via a first multiplexer 5A to the first connection point 3A of the Hall sensor element 2 and the second supply connection 6B is connected via a second multiplexer 5B to a second connection point 3B of the Hall sensor element 2.

[0034] In a second phase of the current supply, the second supply connection 6B is connected via a third multiplexer 5C to a third connection point 3C of the Hall sensor element 2 and the first supply connection 6A is connected via a fourth multiplexer 5D to a fourth connection point 3D of the Hall sensor element 2.

[0035] In a third phase of the current supply, the first supply terminal 6A is connected via the second multiplexer 5B to the second terminal 3B of the Hall sensor element 2, and the second supply terminal 6B is connected via the first multiplexer 5A to the first terminal 3A of the Hall sensor element 2. The excitation current thus flows in the opposite direction in the third phase as in the first phase.

[0036] In a fourth phase of the current supply, the first supply terminal 6A is connected via a third multiplexer 5C to the third terminal 3C of the Hall sensor element 2, and the second supply terminal 6B is connected via the fourth multiplexer 5D to a fourth terminal 3D of the Hall sensor element 2. The excitation current thus flows in the opposite direction in the fourth phase as in the second phase.

[0037] Two further inputs of each multiplexer 5A, 5B, 5C, 5D are electrically connected to input terminals 11, 12 of a measuring device 8, which is designed to measure the voltage between two diametrically opposed terminals 3A, 3B and 3C, 3D, respectively. The measuring device 8 includes a digital-to-analog converter (not shown in detail in the drawing) for digitizing the measured voltages. This converter is connected to a data storage device 9 for storing the measured values. The data storage device 9 is connected to an evaluation unit 47, in which the measured voltage values ​​are processed to compensate for any offset voltages superimposed on the Hall voltages. During the measurement of the Hall voltage, a magnetic flux density flows through the Hall sensor element 2 perpendicular to its plane of extension. This magnetic flux density is not shown in detail in the drawing and may, for example, extend into the plane of the drawing. Fig. 1 can flow into it.

[0038] Multiplexers 5A, 5B, 5C, and 5D each have a control input that is connected to a common control unit 10. By sending a corresponding control signal to the control input, the respective multiplexer 5A, 5B, 5C, or 5D can be configured such that the terminal 3A, 3B, 3C, or 3D connected to the output terminal of the multiplexer 5A, 5B, 5C, or 5D is selectively or alternately electrically connected to or disconnected from one of the inputs of the multiplexer 5A, 5B, 5C, or 5D.

[0039] In Fig. Figure 2 shows the voltages applied to ground potential at the individual connection points 3A, 3B, 3C, 3D during the operation of the Hall sensor 1. In the first phase, with a fault-free Hall sensor 1, the voltage at the first connection point 3A (voltage V) is present. C1 ) of the Hall sensor element 2 the supply voltage V B and at the second connection point 3B (voltage VC2 ) Ground potential. Since the Hall sensor element 2 behaves approximately like a Wheatston bridge, voltages V are present at the third and fourth connection points. C3 and V C4 ) each half of the supply voltage V B against ground when no Hall voltage and no offset voltages are present ( Fig. 3) In practical operation, the voltages at the four connection points 3A, 3B, 3C, 3D may deviate slightly from these values ​​due to the Hall voltage and the offset voltages. This is in Fig. 2 schematically represented by tolerance bands.

[0040] As in Fig. As shown in Figure 4, three tolerance bands result. A lower tolerance band extends from ground potential to a lower reference value T1. A middle tolerance band extends from the lower reference value T1 to an upper reference value T2, and an upper tolerance band extends from the upper reference value T2 to the supply voltage V. B The upper reference value T2 has the value (2 / 3)·V B and the lower reference value T1 has the value (1 / 3)·V B ., where V B The supply voltage provided by the supply source 7 is located between the first and second terminals 3A, 3B.

[0041] To check whether the voltages are within the specified tolerance bands, the Hall sensor 1 has a monitoring device. As in Fig. As can be seen from Figure 5, the monitoring device has a first comparator 13, which has a first input 14 connected to the third terminal 3C, a second input 16 connected to a first terminal of a reference signal generator 15 for an upper reference value signal, and an output 17 for a first comparator signal. A second terminal of the reference signal generator 15 is at ground potential. As can be seen from Fig. If the result is 6, then with a fault-free Hall sensor 1, the voltage at the third terminal 3C in phase 1 must be lower than the upper reference value T2. This is checked using the first comparator 13. If the comparison result does not match this, i.e., the logical value "1" ( Fig. If 7) results, an error signal is generated.

[0042] Furthermore, the Hall sensor 1 has a second comparator 18, which has a third input 19 connected to the third terminal, a fourth input 21 connected to a first terminal of a reference signal generator 20 for a lower reference value signal, and an output 22 for a second comparator signal. A second terminal of the reference signal generator 20 is at ground potential. As can be seen from Fig. If the result is 6, then with a fault-free Hall sensor 1, the voltage at the third terminal 3C in phase 1 must be greater than the lower reference value T1. This is checked using the second comparator 18. If the comparison result does not match this, i.e., if the logical value "0" ( Fig. If 7) results, the error signal is generated.

[0043] A third comparator 23 has a fifth input 24 connected to the fourth terminal 3D, a sixth input 25 connected to the reference signal generator 15 for the upper reference value signal, and an output 26 for a third comparator signal. As can be seen Fig. As can be seen from 6, with a fault-free Hall sensor 1, the voltage at the fourth connection point 3D in phase 1 must be lower than the upper reference value T2. This is checked using the third comparator 23. If the comparison result does not match this, i.e., the logical value "1" ( Fig. If 7) results, the error signal is generated.

[0044] A fourth comparator 27 of the Hall sensor 1 has a seventh input 28 connected to the fourth terminal 3D, an eighth input 29 connected to the reference signal generator 20 for the lower reference value signal, and an output 30 for a fourth comparator signal. As can be seen from Fig. If the result is 6, then with a fault-free Hall sensor 1, the voltage at the fourth connection point 3D in phase 1 must be greater than the lower reference value T1. This is checked using the fourth comparator 27. If the comparison result does not match this, i.e., if the logical value “0” ( Fig. If the result is 7), the error signal is set.

[0045] As in Fig. As can be further seen in Figure 5, the Hall sensor 1 also has a fifth comparator 31, which has a ninth input 32 connected to the first terminal 3A, a tenth input 33 connected to the reference signal generator 15 for the upper reference value signal, and an output 34 for a fifth comparator signal. As can be seen Fig. As can be seen from 6, with a fault-free Hall sensor 1, the voltage at the first connection point 3A in phase 1 must be greater than the upper reference value T2. This is checked using the fifth comparator 31. If the comparison result does not match this, i.e., if the logical value “0” ( Fig. If 7) results, the error signal is generated.

[0046] A sixth comparator 35 has an eleventh input 36 connected to the first terminal 3A, a twelfth input 37 connected to the reference signal generator 20 for the lower reference value signal, and an output 38 for a sixth comparator signal. As can be seen Fig. As can be seen from 6, with a fault-free Hall sensor 1, the voltage at the first connection point 3A in phase 1 must be greater than the lower reference value T1. This is checked using the sixth comparator 35. If the comparison result does not match this, i.e., if the logical value “0” ( Fig. If 7) results, the error signal is generated.

[0047] A seventh comparator 39 of the Hall sensor 1 has a thirteenth input 40 connected to the second terminal 3B, a fourteenth input 41 connected to the reference signal generator 15 for the upper reference value signal, and an output 42 for a seventh comparator signal. As can be seen from Fig. If the result is 6, then with a fault-free Hall sensor 1, the voltage at the second terminal 3B in phase 1 must be lower than the upper reference value T2. This is checked using the seventh comparator 39. If the comparison result does not match this, i.e., if the logical value "1" ( Fig. If 7) results, the error signal is generated.

[0048] Finally, the Hall sensor 1 has an eighth comparator 43, which has a fifteenth input 44 connected to the second terminal 3A, a sixteenth input 45 connected to the reference signal generator 20 for the lower reference value signal T1, and an output 46 for an eighth comparator signal. As can be seen Fig. As can be seen from 6, with a fault-free Hall sensor 1, the voltage at the second terminal 3B in phase 1 must be lower than the lower reference value T1. This is checked using the eighth comparator 43. If the comparison result does not match this, i.e., if the logical value “1” ( Fig. If 7) results, the error signal is generated.

[0049] In the second, third and fourth phases, the voltages at connection points 3A, 3B, 3C, 3D are adjusted according to the entries in rows 2, 3, and 4 of the table. Fig. 6 compared. If a deviation from the target value is detected during at least one check, the evaluation unit 47 generates the error signal and outputs it at an error signal output 48. The in Fig. The six listed (target) comparison results can be stored in the form of a table in the evaluation unit 47 or the data storage unit 9. The individual comparison results are thus linked together in the evaluation unit 47.

Claims

[1] Method for operating a Hall sensor (1), comprising the following steps: a) providing a Hall sensor (1) having a Hall sensor element (2) with a plurality of spaced-apart connection points (3A, 3B, 3C, 3D), and providing a current or voltage supply source (7) having supply terminals (6A, 6B) for outputting a supply current or a supply voltage, b) connecting a first connection point (3A) of the Hall sensor element (2) to a first supply connection (6A) and connecting a second connection point (3B) of the Hall sensor element (2) to a second supply connection (6B) at ground potential in order to apply the supply voltage to the Hall sensor element (2) or to pass the supply current through the Hall sensor element (2), characterized by following further steps: c) providing a lower reference value (T1) and an upper reference value (T2) for a voltage applied to a third connection point (3C) of the Hall sensor element (2) and measured against the ground potential, d) detecting a first voltage value for this voltage, e) comparing the first voltage value with the lower reference value (T1) and the upper reference value (T2), f) generating an error signal depending on the results of these comparisons. [2] Method according to claim 1, comprising the following further steps: a) detecting a second voltage value measured against the ground potential for a voltage applied to a fourth connection point (3D) of the Hall sensor element (2), b) comparing the second voltage value with the lower reference value (T1) and the upper reference value (T2), c) Generating the error signal depending on the results of these comparisons. [3] Method according to claim 1 or 2, comprising the following further steps: a) detecting a third voltage value measured against the ground potential for a voltage applied to the first connection point (3A) of the Hall sensor element (2), b) comparing the third voltage value with the lower reference value (T1) and the upper reference value (T2), c) Generating the error signal depending on the results of these comparisons. [4] Method according to one of claims 1 to 3, comprising the following further steps: a) detecting a fourth voltage value measured against the ground potential for a voltage applied to the second connection point (3B) of the Hall sensor element (2), b) comparing the fourth voltage value with the lower reference value (T1) and the upper reference value (T2), c) Generating the error signal depending on the results of these comparisons. [5] Method according to one of claims 1 to 4, characterized by that the method steps b), d), e) and f) mentioned in claim 1 and optionally the method steps mentioned in claim 2 and / or claim 3 and / or claim 4 are run through several times, wherein in the second and optionally each further run the connection points (3A, 3B, 3C, 3D) of the Hall sensor element (2) are each preferably exchanged cyclically. [6] Hall sensor (1) with a Hall sensor element (2) having a plurality of spaced-apart connection points (3A, 3B, 3C, 3D), with a current or voltage supply source (7) having a first and a second supply connection (6A, 6B) for outputting a supply current or a supply voltage, wherein the first supply connection (6A) for feeding a current into the Hall sensor element (2) is connected to a first connection point (3A) of the Hall sensor element (2) and the second supply connection (6B) is at ground potential and is connected or connectable to a second connection point (3B) of the Hall sensor element (2), characterized bythat the Hall sensor (1) has a reference signal generator (15) for an upper reference signal, which has a first connection and a second connection at ground potential, between which the upper reference value signal is present, that the Hall sensor (1) has a first comparison device (13) which has a first input (14) connected to a third connection point (3C), a second input (16) connected to the first connection of the reference signal generator (15) for the upper reference value signal, and an output (17) for a first comparison signal, that the Hall sensor (1) has a reference signal generator (20) for a lower reference signal, which has a first connection and a second connection at ground potential, between which the lower reference value signal is present, that the Hall sensor (1) has a second comparison device (18) which has a third input (19) connected to the third connection point (3C),a fourth input (21) connected to the first terminal of the reference signal generator (20) for the lower reference value signal and an output (22) for a second comparison signal, and that the outputs (17, 22) of the first and second comparison devices (13, 18) are connected to an evaluation device (47) for generating an error signal dependent on the first and second comparison signals. [7] Hall sensor (1) according to claim 6, characterized bythat the Hall sensor (1) has a third comparison device (23) which has a fifth input (24) connected to the fourth connection point (3D), a sixth input (25) connected to the first connection of the reference signal generator (15) for the upper reference value signal and an output (26) for a third comparison signal, that the Hall sensor (1) has a fourth comparison device (27) which has a seventh input (28) connected to the fourth connection point (3D), an eighth input (29) connected to the first connection of the reference signal generator (20) for the lower reference value signal and an output (30) for a fourth comparison signal, and that the outputs (30) of the third and fourth comparison devices (23, 27) are connected to the evaluation device (47) and the evaluation device (47) is designed such that the error signal is also dependent on the third and fourth comparison signals. [8] Hall sensor (1) according to claim 6 or 7, characterized by that the Hall sensor (1) has a fifth comparison device (31) which has a ninth input (32) connected to the first connection point (3A), a tenth input (33) connected to the first connection of the reference signal generator (15) for the upper reference value signal and an output (34) for a fifth comparison signal, that the Hall sensor (1) has a sixth comparison device (35) which has an eleventh input (36) connected to the first connection point (3A), a twelfth input (37) connected to the first connection of the reference signal generator (20) for the lower reference value signal and an output (38) for a sixth comparison signal, and that the evaluation device (47) is designed such that the error signal is also dependent on the fifth and sixth comparison signals. [9] Hall sensor (1) according to one of claims 6 to 8, characterized bythat the Hall sensor (1) has a seventh comparison device (39) which has a thirteenth input (40) connected to the second connection point (3B), a fourteenth input (41) connected to the first connection of the reference signal generator (15) for the upper reference value signal and an output (42) for a seventh comparison signal, that the Hall sensor (1) has an eighth comparison device (43) which has a fifteenth input (44) connected to the second connection point (3B), a sixteenth input (45) connected to the first connection of the reference signal generator (20) for the lower reference value signal and an output (46) for an eighth comparison signal, and that the evaluation device (47) is designed such that the error signal is also dependent on the seventh and eighth comparison signals. [10] Hall sensor (1) according to claim 9, characterized bythat the Hall sensor (1) has a switching device connected to the supply source (7) and in control connection with a control device, which is designed in such a way a) that in a first operating state - the first and third entrance (14, 19) with the third connection point (3C), - the fifth and seventh input (24, 28) with the fourth connection point (3D), - the ninth and eleventh entrance (32, 36) with the first connection point (3A), - the thirteenth and fifteenth inputs (40, 44) are connected to the second connection point (3B), b) that in a second operating state - the first and third input (14, 19) with the fourth connection point (3D), - the fifth and seventh inputs (24, 28) with the first connection point (3A), - the ninth and eleventh entrance (32, 36) with the second connection point (3B), - the thirteenth and fifteenth inputs (40, 44) are connected to the third connection point (3C), c) that in a third operating state - the first and third inputs (14, 19) with the first connection point (3A), - the fifth and seventh inputs (24, 28) with the second connection point (3B), - the ninth and eleventh entrance (32, 36) with the third connection point (3C), - the thirteenth and fifteenth inputs (40, 44) are connected to the fourth connection point (3D), d) that in a fourth operating mode - the first and third inputs (14, 19) with the second connection point (3B), - the fifth and seventh input (24, 28) with the third connection point (3C), - the ninth and eleventh entrance (32, 36) with the fourth connection point (3D), - the thirteenth and fifteenth inputs (40, 44) are connected to the first connection point (3A), and that the second, sixth, tenth and fourteenth inputs (16, 25, 33, 41) are each connected to the first connection of the reference signal generator (15) for the upper reference value signal and the fourth, eighth, twelfth and sixteenth inputs (21, 29, 37, 45) are each connected to the first connection of the reference signal generator (20) for the lower reference value signal.

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