Patent ID: 11927645
Assignee: INFINEON TECHNOLOGIES AG
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 12:
13. A capacitive sensor, comprising:
a first electrode structure;
a second electrode structure that is counter to the first electrode structure, wherein the second electrode structure is movable relative to the first electrode structure in response to an external force acting thereon, wherein the second electrode structure is capacitively coupled to the first electrode structure to form a first capacitor having a first capacitance that changes with a change in a distance between the first electrode structure and second electrode structure, wherein the first capacitance is representative of the external force,
wherein a pull-in event occurs when the first electrode structure is in direct contact with the second electrode structure causing the first capacitance to be equal to or greater than a pull-in capacitance and a non-pull-in event occurs when the first electrode structure is not in direct contact with the second electrode structure causing the first capacitance to be less than the pull-in capacitance;
a signal generator configured to apply an alternating current (AC) signal at the first electrode structure or the second electrode structure of the first capacitor to induce an output response at an output of first capacitor, wherein the AC signal is a pull-in signal configured to induce a pull-in event in the absence of a fault or a non-pull-in signal configured induce a non-pull-in event in the absence of a fault; and
a diagnostic circuit configured to detect a fault in the capacitive sensor by evaluating the output response and detecting the fault based on the output response and based on whether the AC signal is the pull-in signal or the non-pull-in signal.