18918159. CIRCUIT FOR OPERATING A CAPACITIVE SENSOR AND SENSOR APPARATUS (Robert Bosch GmbH)
CIRCUIT FOR OPERATING A CAPACITIVE SENSOR AND SENSOR APPARATUS
Organization Name
Inventor(s)
Alice Lanniel of Pliezhausen DE
CIRCUIT FOR OPERATING A CAPACITIVE SENSOR AND SENSOR APPARATUS
This abstract first appeared for US patent application 18918159 titled 'CIRCUIT FOR OPERATING A CAPACITIVE SENSOR AND SENSOR APPARATUS
Original Abstract Submitted
A circuit for operating a capacitive sensor which can be operated in first to third modes. A GM stage receives a sensor voltage applied to a sensor output of the capacitive sensor and outputs a current. An integrator integrates the current over a time course and outputs an output voltage resulting therefrom. The circuit provides the output voltage to an analog-to-digital converter. In the first and second modes, the output voltage is provided to the capacitive sensor as a feedback voltage. In the first mode, an offset correction is further performed in the GM stage and the integrator. In the second mode, the sensor output of the capacitive sensor is switched to high impedance. In the third mode, a reference voltage is provided to the capacitive sensor.