MEMS sensor

A micro electro mechanical system sensor, comprising:

• a micro electro mechanical system transducer,
• a micro electro mechanical system interface circuit comprising:
• a first input terminal configured to provide a bias voltage for the micro electro mechanical system transducer and configured to receive a first input signal,
• a second input terminal configured to receive a second input signal from the micro electro mechanical system transducer, and
• at least one output terminal configured to provide at least one output signal, wherein the at least one output signal is a representation of the first and the second input signals,
• wherein the micro electro mechanical system transducer is coupled between the first and the second input terminals of the micro electro mechanical system interface circuit,
• wherein the micro electro mechanical system interface circuit comprises a bias voltage generator, a differential amplifier, a variable capacitor having a variable capacitance and a feedback control circuit,
• wherein the bias voltage generator comprises an output node configured to provide the bias voltage, the output node being connected to the first input terminal of the micro electro mechanical system interface circuit,
• wherein the differential amplifier comprises a first input node and a second input node, the first input node being connected to the first input terminal via the variable capacitor, the second input node being connected to the second input terminal of the micro electro mechanical system interface circuit,
• wherein the differential amplifier comprises at least one output node configured to provide the at least one output signal, the at least one output node being connected to the at least one output terminal of the micro electro mechanical system interface circuit,
• wherein the differential amplifier is configured to provide the at least one output signal at the at least one output node of the differential amplifier,
• wherein the bias voltage generator comprises an output filter having a base terminal, the output filter comprising a capacitor being connected between the base terminal and the output node,
• wherein the at least one output node of the differential amplifier is connected to the base terminal of the output filter of the bias voltage generator via the feedback control circuit,
• wherein the feedback control circuit is configured to provide a feedback signal at the base terminal of the output filter of the bias voltage generator so that the voltage potential at the base terminal of the output filter is changed in the same way as the voltage potential at the output node of the bias voltage generator is changed,
• wherein the first input node of the differential amplifier is configured to be driven only by the bias voltage of the bias voltage generator and the first input signal which is present at the first input terminal,
• wherein the second input node of the differential amplifier is configured to be driven only by the second input signal which is present at the second input terminal, and
• wherein a capacitance of the variable capacitor is configured to be adjusted in dependence on a capacitance of the transducer such that a ratio of the capacitance of the variable capacitor and a parasitic capacitance located at the first input node matches a ratio of the capacitance of the transducer and a parasitic capacitance located at the second input node of the differential amplifier such that any disturbing signal at the output node of the bias voltage generator is symmetrically applied to the first input node and the second input node of the differential amplifier.