Readout-interface circuit for a capacitive microelectromechanical sensor, and corresponding sensor

摘要

In a capacitive sensor (10), a detection structure (11), of a microelectromechanical type, is provided with a fixed element (4) and a mobile element (5), capacitively coupled to one another, generating a capacitive variation (ΔCm) as a function of a quantity to be detected, and with a parasitic coupling element (2), capacitively coupled to at least one between the mobile element (5) and the fixed element (4) generating a first parasitic capacitance (27; 28), intrinsic to the detection structure (11); a readout-interface circuit (12) is connected to the detection structure (11) and generates, on an output terminal (23) thereof, an output signal (Vout) as a function of the capacitive variation (ΔCm). The readout-interface circuit (12) has a feedback path (29) between the output terminal (23) and the parasitic coupling element (2) so as to drive the first intrinsic parasitic capacitance (27; 28) with the output signal (Vout).