Magnetic field sensor system with a temperature response-compensated output signal and method for the temperature response-compensation of an output signal of a magnetic field sensor system

Abstract

The invention relates to a magnetic field sensor system with a temperature response-compensated output signal comprising, a magnetic field sensor subsystem, which preferably comprises two interconnected subsystems, and to a method for the temperature response-compensation of an output signal.

Description

[0001] Magnetic field sensor system with a temperature-compensated output signal and method for temperature compensation of an output signal of a magnetic field sensor system

[0002] Technical area

[0003] The present invention relates to a magnetic field sensor system with a temperature-compensated output signal according to claim 1 and to a method for the temperature-compensation of an output signal of a magnetic field sensor system according to claim 11 or claim 12.

[0004] State of the art

[0005] Sensors for measuring a magnetic field, in particular Hall magnetic field sensors, are known in a sufficiently wide variety and high number from the state of the art.

[0006] The fundamentals of Hall magnetic field sensors are described in great detail, for example, in RS Popovic: "Hall-effect devices", Journal for Sensors and Actuators, Volume 17, Issues 1-2, 3 May 1989, Pages 39-53 or in RS Popovic "Hall Effect Devices", 2nd Edition CRC Press Taylor & Francis Group, LLC 2003, ISBN: 978-1-4200-3422-6.

[0007] Furthermore, the present invention builds on the disclosure of US 6366076 B1. This describes a current sensor that combines the signals from a low-frequency magnetic field sensor, such as a Hall effect sensor, and an inductive coil, such as a Rogowski coil, in a summing device and feeds these summed signals into a low-pass filter. DE 102018128469 B4 discloses a magnetic sensor system with a magnetic sensor, such as a Hall effect sensor, an induction loop, or a coil, which is connected in series with the Hall effect sensor, and the output signal is fed to a low-pass filter.

[0008] These two inventions of US 6366076 B1 and DE 102018128469 disclose a measuring principle how to obtain a broadband (current) sensor by combining a low-frequency magnetic field sensor, such as a Hall effect sensor, and an inductive coil, wherein the signals of the respective signal paths are summed explicitly (US 6366076 B1) and implicitly (DE 102018128469).

[0009] In these inventions described in US 6366076 B1 and DE 102018128469, the measuring principle and the sensor design itself, as well as the arrangement of the sensor within a measuring circuit, are associated with undesirable side effects. For example, the input measurement signal is relatively limited in its bandwidth, for example, an output measurement signal is overlaid with noise.

[0010] A well-known method for reducing offset and low-frequency noise from Hall-effect devices is the use of a switch-based three-phase current technique (spinning current) in combination with a chopper stabilization technique. The use of this combination in sensor systems that include a Hall-effect sensor and an amplifier that amplifies the Hall voltage leads to a reduction in the offset and low-frequency noise of the Hall-effect device.

[0011] Although these and other approaches described in the above-mentioned state of the art provide new methods and circuit arrangements, they do not even remotely provide a solution for stabilizing and tracking the optimal parameters for a smooth frequency response of the output signal of such a sensor system.

[0012] In addition, magnetic field sensor systems with one or more magnetic field sensors are also known from DE 10 2008 061 067 A1 or DE 10 2021 102 051 A1. The aspect that the temperature response of the one or more magnetic field sensors can be compensated for by means of the supply current of a current source clock signal derived from an oscillator is neither known from the prior art in the given context nor suggested to a person skilled in the art.

[0013] Object of the invention

[0014] The object of the invention is to stabilize the operation of a magnetic field sensor system comprising a magnetic field sensor and an inductive element, connectable in series or combined with an explicit summing element, under a wide variety of environmental influences.

[0015] Solution to the task

[0016] To achieve this objective, a magnetic field sensor system having the features of claim 1 and a method of claim 11 or claim 12 are provided. Further advantageous configurations and embodiments of a magnetic field sensor system and the method of claim 12 result from the combination of further features of subclaims 2 to 10.

[0017] Description of the invention

[0018] A magnetic field sensor system with a temperature-compensated output signal Vout comprises a magnetic field sensor subsystem for the temperature response compensation of the output signal Vout, which preferably comprises two interconnected subsystems.

[0019] A first subsystem of the magnetic field sensor subsystem comprises one or more magnetic field sensors selected from the group consisting of Hall effect sensors or other galvano-magnetic sensors such as a tunneling magnetoresistance (TMR), a giant magnetoresistance (GMR), a sensor based on the colossal magnetoresistance effect (CMR) or a sensor based on the anisotropic magnetoresistance effect (AMR).

[0020] A second subsystem of the magnetic field sensor subsystem comprises a power source for powering the one or more magnetic field sensors. The magnetic field sensor system also comprises a low-pass filter and one or more inductive elements electrically connected to this or these magnetic field sensors of the first subsystem, either directly or via a summer.

[0021] For the temperature response compensation of the magnetic field sensor system, the current source supplies the one or more magnetic field sensors with a supply current lh such that the temperature response of the one or more magnetic field sensors can be compensated by means of the supply current l as a function of a current source clock signal derived from an oscillator.

[0022] Preferably, the low-pass filter is designed to change its cutoff frequency fco depending on a filter clock signal such that the temperature dependence of at least one magnetic field sensor can be additionally compensated.

[0023] Preferably, the frequency of the filter clock signal and / or the current source clock signal can be changed in the event of a deviation from a nominal frequency such that the magnetic sensitivity of the one or more magnetic field sensors and the cutoff frequency fco of the low-pass filter are proportional to the frequency of a common clock signal.

[0024] Preferably, the current source for the magnetic field sensor and / or the low-pass filter each comprise one or more switched capacitor circuits.

[0025] Preferably, the capacitance of one or more capacitors of the one or more switched capacitor circuits is programmable.

[0026] Preferably, the oscillator is a voltage-controlled oscillator.

[0027] In embodiments of a magnetic field sensor system, the common clock signal is formed by synchronizing the filter clock signal and the current source clock signal.

[0028] In embodiments of a magnetic field sensor system, the magnetic field sensor system further comprises a compensation control unit configured to provide the filter clock signal, the current source clock signal, or any combination thereof. In embodiments of a magnetic field sensor system, the magnetic field sensor subsystem comprises a further subsystem as a third subsystem with an amplifier for amplifying an output voltage Vh output by at least one magnetic field sensor as a magnetic field sensor signal modulated by switchable contacts.

[0029] In embodiments of a magnetic field sensor system, the magnetic field sensor system and / or the magnetic field sensor subsystem for spinning current operation of a magnetic field sensor and / or chopper stabilization of the amplifier has, in addition to the switchable contacts, switchable contacts, both of which refer to the same clock signal.

[0030] The invention thus represents an essential optimization of a magnetic field sensor system comprising one or more magnetic field sensors, one or more inductive elements, such as an induction coil and / or one or more induction loops, as well as a low-pass filter, since those signals which are generated by a magnetic field in at least one magnetic field sensor and in at least one inductive element are combined with one another and are passed together through the low-pass filter.

[0031] This has the advantage that at relatively low magnetic field frequencies, the magnetic field sensor system produces a virtually frequency-independent signal. The signal from at least one inductive element is proportional to the frequency of the magnetic field. When these two signals are combined and passed through a low-pass filter, the sensor output signal is frequency-independent, from direct current or direct voltage up to very high frequencies.

[0032] The low-pass filter to be used is a first-order low-pass filter with a cutoff frequency equal to the frequency at which the amplitude characteristics of the magnetic field sensor subsystem for the magnetic field sensor and the inductive element are so similar that they intersect at a common point, as shown in Fig. 1. This means that the cutoff frequency f co of the low-pass filter must meet the following condition: fco = (Sh * Gh) / (2 * TT * A * Gc) (1 )

[0033] S describes the absolute magnetic sensitivity of the magnetic field sensor of the magnetic field sensor subsystem, Gh and Gc are the gain factors of the signal coming from the magnetic field sensor and from the inductive element. In the case of an induction coil as the inductive element, A is the area of ​​the induction coil or the effective area of ​​the induction coil, which is determined by

[0034] A = Nc x A a . (2) can be calculated. Nc is the number of turns of the induction coil and Aa is the average area of ​​one turn of the induction coil.

[0035] The advantage of such a magnetic field sensor system, based on the combination of a magnetic field sensor, preferably an induction coil as an inductive element and a low-pass filter, is therefore also a resulting wide bandwidth and low noise.

[0036] Embodiments of such a magnetic field sensor system may also comprise an integrator instead of a low-pass filter, since an integrator has the same technical effect as a low-pass filter if their time constants are the same.

[0037] Equation (1) shows the relationship between the parameters of the magnetic field sensor subsystem, preferably the induction coil as an inductive element and the low-pass filter, which are optimally chosen.

[0038] The present invention shows how to stabilize the parameters of the components of the magnetic field sensor system so that they retain their optimal values ​​regardless of external influences.

[0039] The fulfillment of equation (1 ) is always fulfilled as soon as the magnetic sensitivity of the magnetic field sensor and the cutoff frequency of the low-pass filter are proportional to a common clock signal as a reference clock signal.

[0040] For example, the absolute magnetic sensitivity of the magnetic field sensor is given by

[0041] Sh = K * fei (3) where Kh describes a proportionality coefficient and fei the frequency of the reference clock, and the cutoff frequency of the low-pass filter, i.e. the frequency at which the filter has attenuated the signal amplitude by -3 dB, is given by fco = K f * fei (4) with Kf as a further proportionality coefficient.

[0042] The relationships in equations (3) and (4) can be fulfilled by implementing the current source that supplies the magnetic field sensor with power and / or the low-pass filter as switched capacitors.

[0043] Suitable circuits are shown in the book “Switched Capacitor Circuits”, Phillip E Allen, Springer Netherlands, 1984. A suitable switched-capacitor current source is disclosed in US Patent US 4374357A.

[0044] The absolute magnetic sensitivity of the magnetic field sensor is proportional to the supply current lh:

[0045] Sh = Shi * lh (5) where Shi is the current-related sensitivity of the magnetic field sensor.

[0046] If this current source for the supply current of the magnetic field sensor is now implemented as a switched capacitor circuit, the average current of this source can be expressed as follows: lh = Vr * Ci* fei (6)

[0047] V r is the reference voltage, Ci is the capacitance of the capacitor in this circuit, and fd stands for the frequency of the corresponding clock signal, the current source clock signal.

[0048] If we now replace the supply current lh in equation (5) with the expression from equation (6), we obtain:

[0049] Sh = Shi * Vr * Ci * fei. (7) Now introduce the following notation:

[0050] Kh = Shi * Vr * Ch, (8)

[0051] Thus, equation (7) can be rewritten in the same form as equation (3).

[0052] The coefficient K is practically temperature independent if the reference voltage Vr is designed to have an opposite temperature dependence compared to the current-related sensitivity of the magnetic field sensor Shi.

[0053] This means that the source of the reference voltage Vr is designed to have a positive temperature coefficient when the current-related sensitivity has a negative temperature coefficient, and thus the combination of the two signals is temperature-independent. This can be expressed with the following inequality:

[0054] Shi * Vr + f (T) (9)

[0055] The condition in equation (9) is common for magnetic field sensors based on the Hall effect. Typically, Shi exhibits a linear temperature dependence of approximately -0.1% / °C. Thus, to satisfy equation (9), V r have a linear temperature coefficient of approximately +0.1% / °C.

[0056] The cutoff frequency of a 1st order low-pass filter implemented as a switched capacitor circuit can be calculated using the following equation: fco = (Ci / C2) * fcl / (2 * TT ) (10)

[0057] This expression is well known from various textbooks. If you introduce the following notation:

[0058] Kf = (Ci / C2) / (2 * TT ) (11 ) then equation (10) can be rewritten so that it takes the same form as in equation (4).

[0059] If one replaces in equation (1 ) f co by equation (10), and Shi by equation (7), the following relationships are obtained:

[0060] Ci / C2= (Shi * Vr * Ci * Gh) / (A * Gc) (12) Thus, the condition for the optimal operation of the magnetic field sensor system implemented according to the disclosed invention is shown by the validity of equation (12), which now replaces equation (1).

[0061] The validity of equation (12) can be considered to be practically independent of environmental factors if:

[0062] - Ci, C2, and Ci are implemented as integrated capacitors. If these capacitors are implemented as polysilicon or MOS capacitors (Metal Oxide Semiconductor), they are practically temperature-independent; and / or

[0063] - A is the area of ​​the induction coil or induction loop or effective area of ​​the coil, which is practically independent of temperature; and / or

[0064] - Gh / Gc is the ratio of the voltage gain factors of integrated amplifiers, which can be made largely independent of environmental influences through careful design and matching, as well as placement on the same chip substrate; and / or

[0065] - the product S hi * V r can be made temperature independent by the validity of equation (10).

[0066] Thus, the considered magnetic field sensor system is set up once, i.e. the parameters are adjusted so that equations (1 ) and (13) are satisfied and the settings are retained for any operating temperature.

[0067] Embodiments of a magnetic field sensor system have the advantage that by designing at least one of the capacitances Ci, C2 to Ci according to equation (12) as a digitally programmable capacitance, the initial setting can be advantageously designed.

[0068] An advantageously implemented embodiment of a so-called ratiometric sensor system, which has a magnetic sensitivity proportional to a reference voltage, such as the voltage of the power supply of the magnetic field sensor system. Thus, the clock generator, which serves as the common clock source (reference clock), can be implemented as a voltage-controlled oscillator. Embodiments can also be used in a magnetic field sensor system in which the magnetic field sensor is a Hall-effect sensor with a Hall element as the sensor element or another galvanomagnetic sensor with a magnetoresistive resistance element as the sensor element.

[0069] A method for the temperature response compensation of an output signal of a magnetic field sensor system, which comprises a magnetic field sensor subsystem comprising interconnected subsystems, wherein a first subsystem comprises one or more magnetic field sensors selected from the group consisting of Hall effect sensors or other galvano-magnetic sensors, and a second subsystem of the magnetic field sensor subsystem with a power source for supplying power to the one or more magnetic field sensors, wherein the magnetic field sensor system further comprises a low-pass filter, as well as one or more inductive elements electrically connected to this or these magnetic field sensors of the subsystem, either directly or via a summer, comprises the following steps:

[0070] - determining a supply current as a function of a current source clock signal derived from an oscillator, thereby compensating for the temperature behavior of the one or more magnetic field sensors; and

[0071] - supplying the one or more magnetic field sensors with the determined supply current using the current source.

[0072] A method for the temperature response compensation of an output signal of a magnetic field sensor system with the features of one of the previously described embodiments of a magnetic field sensor system according to one of claims 1 to 10, comprises the steps:

[0073] - determining a supply current as a function of a current source clock signal derived from an oscillator, thereby compensating for the temperature behavior of the one or more magnetic field sensors; and

[0074] - Supplying the one or more magnetic field sensors with the determined supply current using the current source. Accordingly, the application of one of the previously described methods for temperature response compensation of an output signal of a magnetic field sensor system according to the previously described embodiments is also advantageous.

[0075] Further advantages are shown in the figures.

[0076] Fig. 1 shows a frequency-voltage diagram of the frequency responses of partial voltages of a magnetic field sensor system connected to an induction coil as an inductive element as a function of the frequency of a magnetic field;

[0077] Fig. 2 is a block diagram of a magnetic field sensor subsystem;

[0078] Fig. 3 is a block diagram of an embodiment of a magnetic field sensor subsystem connected in series with an induction coil as an inductive element;

[0079] Fig. 4 is a block diagram of an embodiment of a magnetic field sensor subsystem connected in parallel with an induction coil as an inductive element, wherein the respective signal paths each have a separate low-pass filter 1.

[0080] be in order;

[0081] Fig. 5 is a block diagram of another embodiment of a magnetic field sensor subsystem connected in parallel with an induction coil as an inductive element, wherein the two respective signal paths have a common first-order low-pass filter.

[0082] Detailed description of the characters

[0083] Fig. 1 shows a frequency-voltage diagram in which the respective frequency response of partial voltages of a magnetic field sensor system connected to an induction coil as an inductive element is plotted as a function of the frequency of a magnetic field B.

[0084] The curve Vhaii shows the frequency response of an unfiltered output voltage of a magnetic field sensor subsystem.

[0085] The curve Vhaii_F shows the frequency response of a magnetic field sensor subsystem's output voltage filtered with a first-order low-pass filter. The curve Vind shows the frequency response of an unfiltered output voltage of an inductive element.

[0086] The curve Vind F shows the frequency response of an output voltage of an inductive element filtered with a 1st order low-pass filter.

[0087] The curve Vout shows the frequency response of the summed low-pass filtered partial voltages Vhaii and Vind.

[0088] On the x-axis is also the cutoff frequency f co of the 1st order low-pass filter.

[0089] The low-pass filtered partial voltages Vhaii and Vind. are matched in such a way that the respective amplitude responses of the output signals of a magnetic field sensor subsystem and the output signal of an inductive element are congruent.

[0090] Both amplitude responses of the low-pass filtered partial voltages Vhaii and Vind intersect at the cutoff frequency fco of the 1st order low-pass filter.

[0091] Fig. 2 shows a block diagram of an embodiment of a magnetic field sensor subsystem 500 comprising three interconnected subsystems 400, 450 and 1061, as well as supply terminals V+ and V- and electrical contact terminals 501, 502 for outputting an unfiltered output signal Vhaii.

[0092] The subsystem 400 of an embodiment of a magnetic field sensor subsystem 500 comprises a magnetic field sensor 100, to which the switchable contacts 110, 111, 112 are assigned and which can be switched via the contact terminal 503 with control signals indicated by dashed lines.

[0093] In the illustrated embodiment, the magnetic field sensor 100 comprises the magnetic field sensor element 10, which can be selectively coupled via the switchable contacts 110, 111, 112. These switchable contacts thus enable the well-known spinning current technique, wherein the interconnection is preferably designed such that the unamplified sensor signal is modulated by the switchable contacts 110 and 111, and the switchable contact 112 serves to contact the sensor with the amplifier during the measurement process. The magnetic field sensor 100 can comprise one or more such magnetic field sensor elements 10, which can be designed, for example, as planar or vertical Hall sensor elements. The interconnection of the one or more magnetic field sensor elements 10 is achieved via their terminals 1, 2, 3, and 4.

[0094] In the case of a plurality of magnetic field sensor elements 10, such magnetic field sensor elements 10 can be connected to one another in parallel or in series or can be connected to one another in a combination of series and / or parallel connection.

[0095] In embodiments of a magnetic field sensor subsystem 500, other types of magnetic field sensors may also be used, for example sensors that use a galvano-magnetic or magnetoresistive effect (xMR sensors), for example, a tunneling magnetoresistance (TMR), a giant magnetoresistance (GMR), a colossal magnetoresistance effect (CMR), or an anisotropic magnetoresistance effect (AMR).

[0096] Subsystem 450 of an embodiment of a magnetic field sensor subsystem 500 preferably includes an amplifier 40 for amplifying the modulated magnetic field sensor signal Vh and connected switchable contacts 113 for signal demodulation to provide the output signal Vhaii between contact terminals 502 and 503. The control signals for the switchable contacts 113, indicated by dashed lines, are fed via contact terminal 503.

[0097] The subsystem 1061 of an embodiment of a magnetic field sensor subsystem 500 further includes a power source 61 for supplying power to the magnetic field sensor 100.

[0098] The current I of the current source 61 of the subsystem 1061 is preferably variable by means of one or more switched capacitor circuits 62 as a function of the current source clock signal 1702a indicated by dashed lines, which is fed in via the contact terminal 504.

[0099] Fig. 3 shows an embodiment of a magnetic field sensor system comprising a magnetic field sensor subsystem 500, wherein the magnetic field sensor subsystem 500 is connected in series with an inductive element 150, for example in the form of an induction loop or an induction coil. The magnetic field sensor subsystem 500, based on the spinning current technique with the switches 110, 111, 112, 113 (not shown), serves to implement this and includes the subsystem 1061 for the electrical supply of the subsystem 400.

[0100] The output signal Vhaii of subsystem 450, or of magnetic field sensor subsystem 500, is applied as the input signal of the series-connected inductive element 150. The resulting summed signal of the magnetic field sensor subsystem 500 and the inductive element 150 can preferably be amplified with a downstream amplifier 41 with a gain factor Gc, and the signal can be fed to a first-order low-pass filter 1200.

[0101] The sum of the signals of the magnetic field sensor subsystem 500 and the signal of the inductive element 150 is thus filtered.

[0102] The clock signals indicated by dashed lines, namely the current source clock signal 1702a for controlling the current source 1061, the spinning current clock signal 1702b for controlling the switches 110, 111, 112, 113 for the spinning current technique, i.e. the signal modulation and signal demodulation, and the filter clock signal 1702c for controlling the switched capacitor low-pass filter (in German: low-pass filter with switched capacitors) are formed by coordination with the common clock signal 1700.

[0103] Figure 3 also shows that subsystem 1061 and first-order low-pass filter 1200 can be controlled with a common clock signal as a reference clock signal. This means that the respective clock signals, namely current source clock signal 1702a and filter clock signal 1702c, are coordinated with the common clock signal.

[0104] The clock signals 1702a, 1702b, 1702c are coordinated and provided by the compensation control unit 1701. The compensation control unit 1701 is configured such that the clock signals 1702a, 1702b, 1702c are derived from the reference clock signal 1700. The reference clock signal 1700 is provided by the oscillator 1703 as a clock generator. The clock signals 1702a and 1702c are also provided by the compensation control unit 1701 such that the clock signals are proportional to the reference clock signal 1700.

[0105] The output signal Vout of the magnetic field sensor system is ultimately located between the two contact terminals 501 and 502 (not shown).

[0106] Fig. 4 shows a block diagram of an embodiment of a magnetic field sensor system with a magnetic field sensor subsystem 500 comprising the subsystems 400, 450 and 1061. The magnetic field sensor subsystem 500 is connected in parallel with an inductive element 150, for example in the form of an induction loop or an induction coil.

[0107] The output signal of the inductive element 150 can preferably be amplified with a downstream amplifier 41 with a gain factor Gc before being fed to the first-order low-pass filter 1202 as an input signal Vind as a possibly amplified output signal Vind. The first-order low-pass filter 1202 outputs the low-pass filtered and possibly amplified output voltage of the induction coil as an output signal Vind F.

[0108] The output signal Vhaii of subsystem 450, or of magnetic field sensor subsystem 500, is present in the parallel branch of the circuit as the input signal of first-order low-pass filter 1201. The first-order low-pass filter 1201 outputs V aii_F, the low-pass filtered output voltage of subsystem 450, or of magnetic field sensor subsystem 500, as the output signal.

[0109] The two output signals Vind_F and Vhaii_F are summed and are ultimately present as the summed output signal Vout of the sensor system between the two contact terminals 501 and 502 (not shown).

[0110] The first-order low-pass filters 1201 and 1202 arranged along the signal paths of the embodiment of the illustrated magnetic field sensor system before the summation are controllable by the respective filter clock signals 1702d and 1702e.

[0111] The clock signals 1702a, 1702b, 1702d, 1702e are coordinated and provided by the compensation control unit 1701. The compensation control unit 1701 is configured such that the clock signals 1702a, 1702b, 1702d, 1702e are derived from the reference clock signal 1700. The reference clock signal 1700 is provided by the oscillator 1703 as a clock generator.

[0112] The clock signals 1702a, 1702d, 1702e are also provided by the compensation control unit 1701 such that the clock signals are proportional to the reference clock signal 1700.

[0113] Fig. 5 shows a block diagram of an embodiment of a magnetic field sensor system with a magnetic field sensor subsystem 500 comprising the subsystems 400, 450 and 1061. The magnetic field sensor subsystem 500 is connected in parallel with an inductive element 150, for example in the form of an induction loop or an induction coil.

[0114] The output signal of the induction coil 150 can preferably be amplified with a downstream amplifier 41 with a gain factor Gc before it is output as a possibly amplified output signal Vind for summing.

[0115] The output signal Vhaii of the subsystem 450, or of the magnetic field sensor subsystem 500, is output in the parallel branch from output signal Vhaii for summation.

[0116] The two output signals Vind and Vhaii are summed and applied as a summed signal to the first-order low-pass filter 1200 as an input signal. The first-order low-pass filter 1200 outputs Vout as the low-pass filtered summed signal from the possibly amplified output voltage of the inductive element 150 and the output voltage of the magnetic field sensor subsystem 500.

[0117] The output signal Vout of the magnetic field sensor system is ultimately located between the two contact terminals 501 and 502 (not shown).

[0118] Fig. 5 also shows that subsystem 1061 and first-order low-pass filter 1200 are controllable with a common clock signal as reference clock signal 1700. This means that the respective clock signals, namely current source clock signal 1702a and filter clock signal 1702c, are coordinated with the common clock signal.

[0119] The clock signals 1702a, 1702b, 1702c are provided by the

[0120] Compensation control unit 1701 coordinates and provides the compensation control unit. The compensation control unit 1701 is configured such that the clock signals 1702a, 1702b, 1702c are derived from the reference clock signal 1700. The reference clock signal 1700 is provided by the oscillator 1703 as a clock generator.

[0121] The clock signals 1702a and 1702c are also provided by the compensation control unit 1701 such that the clock signals are proportional to the reference clock signal 1700.

[0122] List of reference symbols

Claims

Patent claims Magnetic field sensor system with a temperature response compensated output signal (Vout), wherein the magnetic field sensor system for the temperature response compensation of the output signal (Vout) comprises a magnetic field sensor subsystem (500) comprising interconnected subsystems (400, 1061), wherein - a first subsystem (400) comprises one or more magnetic field sensors (100) selected from the group consisting of Hall effect sensors or other galvano-magnetic sensors; and - a second subsystem (1061) of the magnetic field sensor subsystem (500) having a current source (61) for supplying power to the one or more magnetic field sensors (100); wherein the magnetic field sensor system further comprises a low-pass filter (1200) and one or more inductive elements (150) electrically connected to this or these magnetic field sensors (100) of the subsystem (400) either directly or via a summer (1720), and for temperature response compensation, the current source (61) supplies the one or more magnetic field sensors (100) with a supply current (In) such that the temperature response of the one or more magnetic field sensors (100) can be compensated by means of the supply current (Ih) as a function of a current source clock signal (1702a) derived from an oscillator (1703).Magnetic field sensor system according to claim 1, wherein the low-pass filter (1200) is designed to change its cutoff frequency (fco) as a function of a filter clock signal (1702c) such that the temperature dependence of at least one magnetic field sensor (100) can be additionally compensated. Magnetic field sensor system according to claim 1 or claim 2, wherein the Frequency of the filter clock signal (1702c) and / or the current source clock signal (1702a) are / is variable in the event of a deviation from a nominal frequency such that the magnetic sensitivity of the one or more magnetic field sensors (100) and the cutoff frequency (fco) of the low-pass filter are proportional to the frequency of a common clock signal (1700).

4. Magnetic field sensor system according to claim 1, wherein the current source (1061) for the magnetic field sensor (100) and / or the low-pass filter (1200) each comprise one or more switched capacitor circuits.

5. The magnetic field sensor system of claim 4, wherein the capacitance of one or more capacitors of the one or more switched capacitor circuits is programmable.

6. Magnetic field sensor system according to claim 3, wherein the common clock signal (1700) is formed by synchronizing the filter clock signal (1702c) and the current source clock signal (1702a).

7. The magnetic field sensor system according to any one of claims 2, 3, 5 or 6, wherein the magnetic field sensor system further comprises a compensation control unit (1701) configured to provide the filter clock signal (1702c), the current source clock signal (1702a) or any combination thereof.

8. Magnetic field sensor system according to one of the preceding claims, wherein the magnetic field sensor subsystem (500) comprises a further subsystem 450 with an amplifier (40) for amplifying an output voltage (Vh) output by at least one magnetic field sensor (100) as a magnetic field sensor signal modulated by switchable contacts (112). The magnetic field sensor system according to claim 8, wherein the magnetic field sensor system and / or the magnetic field sensor subsystem (500) comprises, in addition to the switchable contacts (112), switchable contacts (110, 111) for spinning current operation of a magnetic field sensor (100) and / or chopper stabilization of the amplifier (40), both of which are referenced to the same clock signal (1700). The magnetic field sensor system according to claim 1, wherein the oscillator (1703) is a voltage-controlled oscillator. A method for temperature response compensation of an output signal (Vout) of a magnetic field sensor system comprising a magnetic field sensor subsystem (500) comprising interconnected subsystems (400, 1061), wherein - a first subsystem (400) comprises one or more magnetic field sensors (100) selected from the group consisting of Hall effect sensors or other galvano-magnetic sensors; and - a second subsystem (1061) of the magnetic field sensor subsystem (500) with a power source (61) for supplying power to the one or more magnetic field sensors (100); wherein the magnetic field sensor system further comprises a low-pass filter (1200) and one or more inductive elements (150) electrically connected to this or these magnetic field sensors (100) of the subsystem (400) directly or via a summer (1720), the method comprising the steps of: - determining a supply current (lh) as a function of a current source clock signal (1702a) derived from an oscillator (1703), thereby compensating for the temperature behavior of the one or more magnetic field sensors (100); and Supplying the one or more magnetic field sensors (100) with the determined supply current (lh) using the current source (61).

12. Method for temperature response compensation of an output signal (Vout) of a magnetic field sensor system according to one of claims 1 to 10, wherein the method comprises the steps: - determining a supply current (lh) as a function of a current source clock signal (1702a) derived from an oscillator (1703), whereby the temperature behavior of the one or more magnetic field sensors (100); and - supplying the one or more magnetic field sensors (100) with the determined supply current (lh) using the current source (61).

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