System and method for a MEMS sensor
AssigneeInfineon Technologies AG
InventorsDietmar Straeussnigg, Christian Ebner, Ernesto Romani, Stephan Mechnig, Andreas Wiesbauer, Christian Jenkner
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Abstract
According to an embodiment, a sensor circuit includes a sigma-delta analog to digital converter (ADC), a dithered clock coupled to the sigma-delta ADC, and a supply voltage circuit coupled to the sigma-delta ADC. The sigma-delta ADC is configured to be coupled to a low frequency transducer, and the dithered clock is configured to control of the sigma-delta ADC based on a dithered clock signal.
Claims26
A sensor circuit comprising:
- a sigma-delta analog to digital converter (ADC) configured to be coupled to a microelectromechanical systems (MEMS) pressure transducer;
- a dithered clock generator coupled to the sigma-delta ADC, the dithered clock generator configured to produce a dithered clock signal and configured to control the sigma-delta ADC based on the dithered clock signal;
- and
- a supply voltage circuit having an input coupled to the dithered clock generator and a first output configured to be coupled to a capacitive structure of the MEMS pressure transducer, and a second output coupled to a reference voltage input of the sigma-delta ADC, the supply voltage circuit configured to apply a pulsed reference voltage to the capacitive structure of the MEMS pressure transducer according to the dithered clock signal.
A method of operating a sensor, the method comprising:
- receiving an electrical signal from a microelectromechanical systems (MEMS) pressure transducer;
- generating a dithered clock signal;
- generating a pulsed reference voltage according to the dithered clock signal;
- applying the pulsed reference voltage to a capacitive structure of the MEMS pressure transducer;
- and
- converting the electrical signal into a digital signal using a sigma-delta analog to digital converter (ADC) operating based on the dithered clock signal.
A microelectromechanical systems (MEMS) capacitive pressure sensor system comprising:
- a differential output MEMS capacitive pressure sensor comprising:
- a first reference capacitive structure,
- a first variable capacitance structure configured to vary a first capacitance value in reference to a first pressure signal,
- a first output coupled between the first reference capacitive structure and the first variable capacitance structure,
- a second reference capacitive structure,
- a second variable capacitance structure configured to vary a second capacitance value in reference to a second pressure signal, and
- a second output coupled between the second reference capacitive structure and the second variable capacitance structure;
- a differential amplifier coupled to the first output and the second output of the differential output MEMS capacitive pressure sensor;
- a sigma-delta analog to digital converter (ADC) coupled to an output of the differential amplifier;
- a dithered clock generator coupled to the sigma-delta ADC, the dithered clock generator configured to generate a dithered clock signal, and configured to control a sampling time of the sigma-delta ADC using the dithered clock signal;
- and
- a supply voltage circuit having an input coupled to the dithered clock generator and a first output coupled to the first variable capacitance structure and the second variable capacitance structure, the supply voltage circuit configured to generate a pulsed reference voltage at the first output based on the dithered clock signal.
Dependencies are inferred from the claim text.