Detection circuit using a differential capacitive sensor with input-common-mode control in a sense interface

A detection circuit is provided with a differential capacitive sensor and with an interface circuit having a first sense input and a second sense input, electrically connected to the differential capacitive sensor. Provided in the interface circuit are: a sense amplifier connected at input to the fi...

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Bibliographische Detailangaben
Hauptverfasser: LASALANDRA ERNESTO, UNGARETTI TOMMASO
Format: Patent
Sprache:eng
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Beschreibung
Zusammenfassung:A detection circuit is provided with a differential capacitive sensor and with an interface circuit having a first sense input and a second sense input, electrically connected to the differential capacitive sensor. Provided in the interface circuit are: a sense amplifier connected at input to the first sense input and to the second sense input and supplying an output signal related to a capacitive unbalancing of the differential capacitive sensor; and a common-mode control circuit, connected to the first sense input and to the second sense input and configured to control a common-mode electrical quantity present on the first sense input and on the second sense input. The common-mode control circuit is of a totally passive type and is provided with a capacitive circuit, which is substantially identical to an equivalent electrical circuit of the differential capacitive sensor and is driven with a driving signal in phase opposition with respect to a read signal supplied to the differential capacitive sensor.