Abstract: A sensor circuit for measuring a physical or chemical quantity comprises a capacitive sensor. A sense and a base electrode of the sensor form a capacitive element with a capacity depending on the quantity. A common electrode of the sensor forms a first and a second parasitic capacitance together with the sense and the base electrode, respectively. The sensor circuit is adapted to store a charge on the capacitive element and to read out the stored charge via the sense electrode. A buffer element is connected between the sense electrode and the common electrode and adapted to drive the common electrode at a voltage applied to the sense electrode.
Type:
Grant
Filed:
March 29, 2016
Date of Patent:
July 2, 2019
Assignee:
ams AG
Inventors:
José Manuel García González, Rafael Serrano Gotarredona