DE102020211325A1 - Sensor system comprising a micromechanical differential sensor element with a movable mass structure - Google Patents

Abstract

A sensor system is claimed, comprising- a micromechanical differential sensor element with a movable mass structure, which comprises at least a first partial structure and a second partial structure, wherein the at least two partial structures can be deflected in opposite directions or in the same direction from a rest position, and the sensor element is equipped with a first sensor electrode arrangement for detecting movements of the first partial structure and with a second sensor electrode arrangement for detecting movements of the second partial structure, and- a readout circuit with a first input which is connected to the first sensor electrode arrangement and a second input which is connected to the second sensor electrode arrangement is characterized in that the readout circuit comprises circuit means for generating at least one compensation voltage V a, and to use the compensation voltage Va to compensate for a change in charge on the first sensor electrode arrangement and/or on the second sensor electrode arrangement when the first and the second partial structure are deflected in the same direction from the rest position.

Description

State of the art

The invention is based on a sensor system according to the preamble of claim 1.

Microelectromechanical systems (MEMS), such as gyroscopes, are used as sensors in a variety of electrical devices. There are constantly new and diverse application possibilities, such as in indoor navigation or augmented reality. MEMS are also being integrated into new types of devices and products, such as drones.

In many applications, the environment in which the MEMS is used is susceptible to external vibrations, which can be caused, for example, by motors or speakers in the vicinity of the MEMS.

For various MEMS, such as gyroscopes, it is therefore important to develop concepts that enable high-quality suppression of interference caused by such external vibrations.

Approaches are known here that try to solve the negative influences of external vibrations by adapting the mechanical structures of the gyroscope. Thus, fully symmetrical double-mass structures that are intrinsically more robust to vibrations and/or mechanical structures with increased stiffness along the vibration axis can be used. In this way, the vibrations excite a common mode in the two sensing electrodes and the spurious signal is rejected across the two sensing electrodes at the electrical front end of the sensing. However, even in this case, the potential at which the input nodes of the electrical detection are held generates an electrical force acting on the MEMS electrode capacitors, which can potentially worsen the noise caused by the vibrations. Problems, errors and inaccuracies can therefore arise in various applications.

Disclosure of Invention

It is an object of the present invention to provide a sensor system that has improved robustness to external linear accelerations and/or vibrations.

The sensor system according to the invention according to the main claim has the advantage over the prior art that when the first partial structure and the second partial structure are deflected from the rest position in the same direction, a change in charge on the first sensor electrode arrangement and/or on the second sensor electrode arrangement can be compensated for, resulting in a possible feedback force on the sensor electrode assemblies can be minimized. As a result, interference from external linear accelerations, such as vibrations, which lead to a deflection of the substructures in the same direction, can be minimized or prevented.

If the first and second partial structures deflect in the same direction from the rest position, the capacitances of the first and second sensor electrode arrangements change. For example, in the event that a constant voltage is present at the electronic input of the readout circuit, the common mode charges on the two sensor electrode arrangements would change as a result of these changes in capacitance. This would create a feedback force that could even amplify the induced interference signals if the substructures were deflected in the same direction.

This disadvantage is overcome according to the invention since at least one compensation voltage V _a is generated on the basis of the voltage V _{inp present} at the first input and the voltage V _inn present at the second input. With the help of this compensation voltage V _a it is advantageously possible to compensate for a change in charge on the first sensor electrode arrangement and/or on the second sensor electrode arrangement when the first and second substructures are deflected in the same direction from the rest position. It is thus preferably possible to keep the charge on the first sensor electrode arrangement and/or on the second sensor electrode arrangement constant in the event of external vibrations.

According to the invention, the force feedback which acts on the electrodes in systems known from the prior art as a result of a mechanical common-mode signal can thus be reduced. A build-up of a mechanical common-mode signal on the MEMS due to force feedback can thus advantageously be avoided. This can reduce noise of the MEMS caused by vibration, enabling improved applicability of the sensor in a variety of products and situations.

Advantageous configurations and developments of the invention can be found in the subclaims and the description with reference to the drawings.

The fact that, according to one embodiment of the present invention, the circuit means comprises at least one operational amplifier, a weighted or unweighted sum of the voltage V _{inp present} at the first input and the voltage V _inn present at the second input being fed to the at least one operational amplifier as an input signal, and wherein the at least one operational amplifier supplies the at least one compensation voltage V _a as an output signal, it is advantageously possible for the compensation voltage to be provided as a function of the voltages V _inp and V _inn present at the inputs. This results in a particularly advantageous and efficient compensation for the charge changes on the sensor electrode arrangements. The voltages V _inp and V _inn can be applied to the inputs by one or more controller circuits of the readout circuit, for example.

According to one embodiment of the present invention, a first parasitic capacitance _Cpp is present at the first input and/or a second parasitic capacitance Cp is present at the second input, the at least one compensation voltage V _a being applied to the first input via a first compensation capacitance _Ccp is fed back and/or is fed back to the second input via a second compensation capacitance C _cn , it is advantageously possible that a current flow between the parasitic capacitances and the sensor electrode arrangements caused by the mechanical vibrations can be compensated for.

Because according to one embodiment of the present invention, a common operational amplifier is provided for generating a common compensation voltage V _a , the common compensation voltage V _a being fed back to the first input via the first compensation capacitance C _cp and to the second input via the second compensation capacitance C _cn Input is fed back, and wherein the gain factor G of the common operational amplifier, the first compensation capacitance C _cp and the second compensation capacitance C _cn are selected so that the parasitic capacitances C _pp , C _p , induced currents i _pp and i _pn and the If the currents i _cp and i _cn flowing via the feedback compensation capacitors C _cp , C _cn cancel each other out, it is advantageously possible to enable efficient compensation using a common operational amplifier. As a result, a particularly advantageous system can be implemented, with a common compensation voltage V _a being generated, which is fed back via corresponding compensation capacitances both to the first input and to the second input. In this case, the gain factor G of the common operational amplifier, the first compensation capacitance C _cp and the second compensation capacitance C _cn are preferably matched to one another in order to achieve high-quality charge carrier compensation on the two sensor electrode arrangements.

• G = (C_e + C_p) / C_e, ist es möglich, eine vorteilhafte Kompensation für ein symmetrisch ausgestaltetes Gyroskop mit symmetrischen parasitären Kapazitäten am ersten und zweiten Eingang zu ermöglichen, wodurch ferner Störsignale durch eine Common Mode besonders vorteilhaft zurückgewiesen werden können.

Due to the fact that, according to one embodiment of the present invention, the gyroscope is configured essentially symmetrically, so that essentially the same parasitic capacitances C _pp = C _p , = C _p are present at the first input and at the second input of the readout circuit, with essentially the same compensation capacitances C _ep = C _cn = C _c are provided for feeding back the compensation voltage V _a to the first input and the second input, and wherein the gain factor G of the common operational amplifier is chosen as a function of the parasitic capacitance C _p and the compensation capacitance C _e as:

• G=(C _e +C _p )/C _e , it is possible to enable an advantageous compensation for a symmetrically configured gyroscope with symmetric parasitic capacitances at the first and second input, as a result of which interference signals can also be particularly advantageously rejected by a common mode.

In that, according to one embodiment of the present invention, a first operational amplifier is provided for generating a first compensation voltage V _a1 , and the first compensation voltage V _a1 is fed back to the first input via the first compensation capacitance C _cp , and a second operational amplifier for generating the second compensation voltage V _a2 is provided, and with the second compensation voltage V _a2 being fed back to the second input via the second compensation capacitance C _cn , it is possible to compensate for the first and the second sensor electrode structure using self-generated compensation voltages V _a1 and V _a2 .

und dass der Verstärkungsfaktor G₂ des zweiten Operationsverstärkers in Abhängigkeit von der zweiten parasitären Kapazität C_pn und der zweiten Kompensationskapazität C_cn gewählt ist als: $${\text{G}}_{\text{2}}=\left({\text{C}}_{\text{cn}}+{\text{C}}_{\text{pn}}\right)/{\text{C}}_{\text{cn}}.$$

Somit können für den ersten und zweiten Eingang jeweils eigene Operationsverstärker zur Erzeugung von Kompensationsspannungen vorgesehen sein, was eine besonders hohe Flexibilität bei der Ausgestaltung des Sensorsystems ermöglicht.According to one embodiment of the present invention, it is conceivable that the gain factor G ₁ of the first operational amplifier is selected as a function of the first parasitic capacitance Cpp and the first compensation capacitance C _cp as: $${\text{<figure-callout id="1" label="G" filenames="DE102020211325A1\_0019.png" state="{{state}}">G</figure-callout>}}_{\text{1}}=\left({\text{C}}_{\text{cp}}+{\text{C}}_{\text{pp}}\right)/{\text{C}}_{\text{cp}}$$

and that the gain factor G ₂ of the second operational amplifier depending on the second parasitic capacitance C _pn and the second compensation capacitance C _cn is chosen as: $${\text{G}}_{\text{2}}=\left({\text{C}}_{\text{cn}}+{\text{C}}_{\text{PM}}\right)/{\text{C}}_{\text{cn}}.$$

Thus, separate operational amplifiers for generating compensation voltages can be provided for the first and second input, which allows a particularly high degree of flexibility in the design of the sensor system.

According to one embodiment of the present invention, it is provided that the sensor element is a gyroscope. Feedback forces and ultimately spurious signals that can be caused by external vibrations in a MEMS gyroscope can be suppressed accordingly, which allows the use of MEMS gyroscopes in a variety of applications in which mechanical vibrations are generated in the environment of the gyroscope and / or are transmitted to the gyroscope, particularly advantageously allows. The mobile mass structure of the gyroscope is set up to record yaw rates.

Exemplary embodiments of the present invention are illustrated in the drawings and explained in more detail in the following description.

character list

• 1 shows a schematic representation of a micromechanical differential sensor element according to an embodiment of the present invention;
• 2 shows a schematic representation of a sensor system according to the prior art;
• 3 shows a schematic representation of a sensor system according to an embodiment of the present invention;
• 4 shows a schematic representation of a sensor system according to an embodiment of the present invention.

Embodiments of the invention

In the various figures, the same parts are provided with the same reference symbols and are therefore usually named or mentioned only once.

In 1 1 is a schematic representation of a micromechanical differential sensor element 10 according to an embodiment of the present invention. The sensor element 10 is preferably a microelectromechanical gyroscope. The sensor element 10 includes a movable mass structure 11 which includes at least a first substructure 12 and a second substructure 13 . The two partial structures 12, 13 can be deflected from a rest position both in opposite directions and in the same direction. The two partial structures 12, 13 can be two partial masses of the mass structure 11, for example.

In 2 1 is a schematic representation of a sensor system according to the prior art, only one half of a differential sensor system being represented. On the one hand, the sensor system comprises a sensor element 10 with a movable mass structure 11 which comprises a first and second partial structure 12, 13. A first sensor electrode arrangement 15 with a capacitance Cs is configured for detecting movements of the first substructure 12 and a second sensor electrode arrangement 16 is configured for detecting movements of the second substructure 13 . The interface between the first sensor electrode arrangement 15 and a first input 21 of the readout circuit 20, which is set up to read out a sensor signal from the sensor electrode arrangement 15, is also shown. The circuit includes parasitic capacitances C _p and a capacitance C _f . In the prior art, the input of the electronics or the readout circuit 20 is often kept at a constant voltage V _in with a controller, since this is typically advantageous for the biasing of the front-end amplifier. Alternatively, the input is controlled with a discrete-time controller or a simple periodic reset that leaves the input behaving freely or moving freely according to the common mode, based on the capacitance divider between the sensor electrode capacitance and the total capacitance of the input . In both cases, the charge stored on the sensor electrode arrangement 15 changes when the mass structure 10 is deflected in the same direction due to the change in capacitance of the sensor electrode arrangement 15. This results in a disadvantageous feedback force when the substructures 12, 13 move in the same direction or in a common mode on the sensor electrode arrangement 15.

However, such disadvantages can be overcome according to the invention, as illustrated by the following explanations. According to the present invention, it is possible to use at least one compensation voltage V _a to compensate for a change in charge on a first sensor electrode arrangement 15 and/or on a second sensor electrode arrangement 16 when the first and the second partial structure 12, 13 are deflected in the same direction from the rest position.

In a rest position, the charge Q ₀ stored on a sensor electrode assembly is Qo = C ₀ V ₀ , where C ₀ is the electrode capacitance of the sensor electrode assembly is in the rest position and where V ₀ is the voltage between the two plates (or structures) of the sensor electrode assembly.

sein.In order to keep the charge constant when the capacitance C _s of the sensor electrode assembly changes according to C _s =C ₀ +C _(u(t)) by an external signal such as a vibration, the applied voltage must $$V=\frac{Q_0}{C_s}$$

be.

If this condition is met, the electrostatic potential energy U _e stored on the sensor electrode assembly can be represented as follows: $$u_e=\frac{1}{2}{C}_s{V}^2=\frac{Q_0^2}{C_s}.$$

wobei ε die Dielektrizitätskonstante,
A die Fläche der Platte,
g₀ der Plattenabstand im Ruhezustand und
u die Änderung des Plattenabstands durch das externe Signal ist.For a parallel plate capacitor: $$C_s=\frac{eA}{G_0+\mathrm{and}},$$

where ε is the dielectric constant,
A is the area of the plate,
g ₀ the disk spacing at rest and
u is the change in plate spacing due to the external signal.

The electrostatic potential energy is therefore as follows: $$u_e=\frac{C_0}{C_s}{Q}_0{V}_0=\left(1+\frac{\mathrm{and}}{G_0}\right)Q_0{V}_0.$$

The electrostatic force F _e acting on the electrode results from the derivation of the electrostatic potential energy: $$f_e=-\frac{\mathrm{i.e}{u}_e}{\mathrm{i.e}\mathrm{and}}=-\frac{Q_0}{G_0}{V}_0.$$

If the condition is met that the charge on the sensor electrode arrangement is constant, the force F _e that acts on the sensor electrode arrangement is constant and independent of the change in the plate distance u and thus in particular also independent of the external mechanical signal (or the Vibration).

In 3 1 is a schematic representation of a sensor system 1 according to an embodiment of the present invention, with which the charge on a sensor electrode arrangement can be kept constant. In 3 only one half of the sensor system 1 or of the differential sensor element 10 is shown for reasons of representation. The sensor system 1 includes the sensor element 10 with a movable mass structure 10, which includes a first and second partial structure 12,13. A first sensor electrode arrangement 15 with a capacitance C _sp is configured to detect movements of the first substructure 12 . Furthermore, the first interface 22 between the first sensor electrode arrangement 15 and a first input 21 of the readout circuit 20 is shown. The readout circuit 20 is set up to read out signals from the first sensor electrode arrangement 15 . The system has a controller circuit 40 which applies a voltage V _inp , in particular a constant voltage, to the first input 21 .

Based on the in 3 shown embodiment, the concept of the present invention for the illustrated half of the differential sensor element is further explained. Since the current i _sp flowing out of (or into) the capacitance C _sp of the sensor electrode assembly 15 corresponds to the derivative of the charge Q _sp with respect to time, it must - in order to achieve a constant charge Q _sp on the sensor electrode assembly 15 - that the current isp = 0.

wobei i_cp der über der die erste Kompensationskapazität C_cp rückgekoppelte Strom ist und ipp der über die ersten parasitären Kapazitäten Cpp fließende Strom ist.This gives the condition: $$i_{cp}=-i_{pp},$$

where i _cp is the current fed back via the first compensation capacitance C _cp and ipp is the current flowing via the first parasitic capacitances Cpp.

By including a first compensation voltage V _a1 , which is fed back to the first input 21, the result is: $$\frac{\mathrm{i.e}{C}_{cp}\left(V_{inp}-V_{a1}\right)}{\mathrm{i.e}t}=\frac{\mathrm{i.e}{C}_{pp}{V}_{inp}}{\mathrm{i.e}t}\to V_{a1}=\frac{C_{cp}+C_{pp}}{C_{cp}}{V}_{inp}.$$

The first compensation voltage V _a1 can therefore be generated from the voltage V _{inp present} at the first input 21, in particular using an amplifier with the following gain G: $$G=\frac{C_{cp}+C_{pp}}{C_{cp}}.$$

This gain G is provided by the operational amplifier 30, which supplies the first compensation voltage V _a1 as an output signal. The first compensation voltage V _a1 generated in this way is fed back to the first input 21 via the first compensation capacitance C _cp .

The change in charge on the first sensor electrode arrangement 15 can thus be compensated for.

The same considerations apply to the second input 23 of the readout circuit 20, at which the signal of the second sensor electrode arrangement 16 is detected (in 3 not shown).

In 4 a schematic representation of a sensor system 1 according to an embodiment of the present invention is shown. A differential system with the two sensor electrode arrangements 15, 16 for the two substructures 12, 13 and the two inputs 21, 23 of the readout circuit 20 is shown here. The first sensor electrode arrangement 15 with its capacitance C _sp is configured to detect movements of the first partial structure 12 and is connected to the first input 21 of the readout circuit 20 . The second sensor electrode arrangement 16 with its capacitance C _sn is configured to detect movements of the second partial structure 13 and is connected to the second input 23 of the readout circuit 20 . The first interface 22 and the second interface 24 represent the boundary or the connection of the readout circuit 20 to the sensor element 10.

The above considerations apply to the first input 21 and the charge compensation of the first sensor electrode arrangement 15 .

Correspondingly, for the second input 23 and the second sensor electrode arrangement 16, the current i _sn flowing out of (or into) the capacitance C _sn of the second sensor electrode arrangement 16 corresponds to the derivative of the charge Q _sn on the second sensor electrode arrangement 16 with respect to time . In order to achieve a constant charge Q _sn it must be true that the current i _sn = 0.

wobei i_en der über der die zweite Kompensationskapazität C_cn rückgekoppelte Kompensationsstrom ist und i_pn der aus der zweiten Sensorelektrodenanordnung 16 in die zweiten parasitären Kapazitäten C_pn fließende Strom ist (oder umgekehrt aus den zweiten parasitären Kapazitäten C_pn in die zweite Sensorelektrodenanordnung 16).This gives the condition: $$i_{cn}=-i_{pn},$$

where i _en is the compensation current fed back via the second compensation capacitance C _cn and i _pn is the current flowing from the second sensor electrode arrangement 16 into the second parasitic capacitances C _pn (or vice versa from the second parasitic capacitances C _pn into the second sensor electrode arrangement 16).

By including a second compensation voltage V _a2 , which is fed back to the second input 23, the result is: $$\frac{\mathrm{i.e}{C}_{cn}\left(V_{inn}-V_{a2}\right)}{\mathrm{i.e}t}=\frac{\mathrm{i.e}{C}_{pn}{V}_{inn}}{\mathrm{i.e}t}\to V_{a2}=\frac{C_{cn}+C_{pn}}{C_{cn}}{V}_{inn}.$$

The second compensation voltage V _a2 can therefore be generated from the voltage V _inn present at the second input 23, in particular with an amplification stage with the following amplification G: $$G=\frac{C_{cn}+C_{pn}}{C_{cn}}.$$

This gain G is provided by the operational amplifier 30 (or a second operational amplifier), which provides the second compensation voltage V _a2 as an output signal. The second compensation voltage V _a2 generated in this way is fed back to the second input 23 via the second compensation capacitance C _cn . The change in charge on the second sensor electrode arrangement 16 can thus be compensated for.

The charge changes on the sensor electrode arrangements 15, 16 or in the capacitances C _sp and C _sn are thus compensated for a common-mode mode or a deflection of the partial structures 12, 13 in the same direction. In contrast, the differential charge representing the desired signal (e.g., a yaw rate signal) can be read out with a C/V converter or another fully differential readout circuit.

At the in the 4 The illustrated embodiment implements a common operational amplifier 30 for generating a common compensation voltage V _a =V _a1 =V _a2 . On the basis of the voltage V _{inp present} at the first input 21 and the voltage V _inn present at the second input 23, the common operational amplifier 30 thus generates the common compensation voltage V _a . This compensation voltage V _a is fed back to the first input 21 via the first compensation capacitance C _cp and fed back to the second input 23 via the second compensation capacitance C _cn . The amplification factor G of the common operational amplifier 30, the first compensation capacitance C _cp and the second compensation capacitance C _cn are chosen in such a way that the currents ipp and i pn induced by the parasitic capacitances C _pp , C _p , and the currents ipp and i _pn via the feedback compensation capacitances C _cp , C _cn currents i _cp and i _cn cancel each other out. Alternatively, it is also conceivable that a first operational amplifier is provided for generating the first compensation voltage V _a1 and that the first compensation voltage V _a1 is fed back to the first input 21 via the first compensation capacitance C _cp , with a second operational amplifier for generating the second compensation voltage V _a2 is provided, and wherein the second compensation voltage V _a2 via the second compensation capacitor capacity C _cn is fed back to the second input 23 .

the 3 and 4 thus show embodiments in which at least one compensation voltage V _a is generated on the basis of the voltage V _{inp present} at the first input 21 and the voltage V _inn present at the second input 23, with the compensation voltage V _a being used to produce a charge change on the first sensor electrode arrangement 15 and/or is compensated for on the second sensor electrode arrangement 16 when the first and the second partial structure 12, 13 are deflected in the same direction from the rest position.

Claims (8)

Sensor system (1), comprising - a micromechanical differential sensor element (10) with a movable mass structure (11) which comprises at least a first partial structure (12) and a second partial structure (13), the at least two partial structures (12, 13) being in opposite directions or can be deflected in the same direction from a rest position, and wherein the sensor element (10) is equipped with a first sensor electrode arrangement (15) for detecting movements of the first partial structure (12) and with a second sensor electrode arrangement (16) for detecting movements of the second partial structure ( 13), and - a readout circuit (20) having a first input (21) connected to the first sensor electrode arrangement (15) and a second input (23) connected to the second sensor electrode arrangement (16), characterized in that that the readout circuit (20) comprises circuit means, on the basis of the first input (21) applied voltage V _inp and the second n input (23) applied voltage V _inn to generate at least one compensation voltage V _a , and to use the compensation voltage V _a to compensate for a charge change on the first sensor electrode arrangement (15) and/or on the second sensor electrode arrangement (16) when the first and the second partial structure (12, 13) are deflected in the same direction from the rest position. sensor system claim 1 , characterized in that the circuit means comprise at least one operational amplifier (30), in that the at least one operational amplifier (30) receives a weighted or unweighted sum of the voltage V _{inp present} at the first input (21) and the voltage V _inn is supplied as an input signal, and that the at least one operational amplifier (30) supplies the at least one compensation voltage V _a as an output signal. Sensor system according to one of Claims 1 or 2 , wherein a first parasitic capacitance Cpp is present at the first input (21) and/or a second parasitic capacitance C _pn is present at the second input (23), characterized in that the at least one compensation voltage V _a is applied via a first compensation capacitance C _cp to the first Input (21) is fed back and / or via a second compensation capacitance C _cn is fed back to the second input (23). sensor system according to claims 2 and 3 , characterized in that a common operational amplifier (30) is provided for generating a common compensation voltage V _a , that the common compensation voltage V _a is fed back to the first input (21) via the first compensation capacitance C _cp and via the second compensation capacitance C _cn is fed back to the second input (23), and that the gain factor G of the common operational amplifier (30), the first compensation capacitance C _cp and the second compensation capacitance C _cn are selected in such a way that the currents ipp. induced via the parasitic capacitances Cpp, C _pn and i _pn and the currents i _cp and i _cn flowing via the feedback compensation capacitances C _cp , C _cn cancel each other out. sensor system claim 4 , wherein the gyroscope (10) is configured essentially symmetrically, so that the first input (21) and the second input (23) of the readout circuit (20) have essentially the same parasitic capacitances C _pp = C _pn = C _p , characterized in that that substantially equal compensation capacitances C _cp = C _cn = C _c are provided for feeding back the compensation voltage V _a to the first input (21) and the second input (23), and that the gain factor G of the common operational amplifier (30) depends from the parasitic capacitance C _p and the compensation capacitance C _e is chosen as: $$\text{G}=\left({\text{C}}_{\text{c}}+{\text{C}}_{\text{p}}\right)/{\text{C}}_{\text{c}}.$$

sensor system according to claims 2 and 3 , characterized in that a first operational amplifier is provided for generating a first compensation voltage V _a1 , and in that the first compensation voltage V _a1 is fed back to the first input (21) via the first compensation capacitance C _cp , and and in that a second operational amplifier for generating the second compensation voltage V _a2 is provided, and that the second compensation voltage V _a2 is fed back to the second input (23) via the second compensation capacitance C _cn . sensor system claim 6 , characterized in that the gain factor G ₁ of the first operational amplifier depending on the first parasitic capacitance Cpp and the first compensation capacitance C _cp is chosen as: $${\text{G}}_{\text{1}}=\left({\text{C}}_{\text{cp}}+{\text{C}}_{\text{pp}}\right)/{\text{C}}_{\text{cp}}$$

and that the gain factor G ₂ of the second operational amplifier depending on the second parasitic capacitance C _pn and the second compensation capacitance C _cn is chosen as: $${\text{G}}_{\text{2}}=\left({\text{C}}_{\text{cn}}+{\text{C}}_{\text{PM}}\right)/{\text{C}}_{\text{cn}}.$$

Sensor system according to one of Claims 1 until 7 , characterized in that the sensor element (10) is a gyroscope.

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