METHOD AND APPARATUS FOR DETECTING A CHANGE IN CAPACITANCE OF A CAPACITIVE PROXIMITY SENSOR

摘要

A method for detecting a change in capacitance of a capacitive sensing element having a nominal capacitance value is disclosed. In an exemplary embodiment, the method includes coupling the sensing element to a first oscillator (42), the first oscillator generating a first frequency dependent on the capacitance value of the first sensing element. The first frequency is compared to a reference frequency generated by a reference oscillator (40). The change in capacitance from the nominal capacitance value is detected if the first frequency differs from said reference frequency by a determined frequency value.