Patent ID: 8723532

Claim:
A capacitive proximity device for sensing a presence and/or absence of an object in proximity of an electronic device, the capacitive proximity device comprising: an emission electrode capacitively coupled to a receiver electrode; an oscillator configured to generate an emission-signal being an alternating electric field between the emission electrode and the receiver electrode; and a sensing circuit connected to the receiver electrode, the sensing circuit receiving a measured-signal from the receiver electrode, and comprising a detection circuit configured to generate an output-signal being proportional to a distance between the object and the electronic device, the measured-signal comprising noise, and the sensing circuit further comprising a noise-suppressor configured to reduce noise from the measured-signal before entering the detection circuit, wherein the noise-suppressor comprises a first differential amplifier configured to generate a noise-signal comprising at least a part of the noise from the measured-signal by subtracting a correction-signal from the measured-signal, the correction-signal having substantially a same frequency and phase as the emission-signal and having an amplitude proportional to a sensed-emission-signal.