CAPACITIVE PROXIMITY DEVICE AND ELECTRONIC DEVICE COMPRISING THE CAPACITIVE PROXIMITY DEVICE

摘要

A capacitive proximity device for sensing a presence and/or absence of an object in the proximity of an electronic device includes an emission electrode capacitively coupled to a receiver electrode, an oscillator for generating an emission-signal being an alternating electric field between the emission electrode and the receiving electrode, and a sensing circuit connected to the receiving electrode. The sensing circuit receives a measured-signal from the receiver electrode and includes a first synchronous detection circuit together with a low-pass filter for generating an output-signal being proportional to a distance between the object and the electronic device. The sensing circuit further includes a noise-suppresser for reducing noise from the measured-signal before entering the first synchronous detection circuit.