Capacitance Sensor And Sensing Device

Abstract

A capacitance sensor connected to a sensing electrode forming a first capacitance between the sensing electrode and a first conductor includes a package, a sensing terminal disposed in the package and electrically connected to the sensing electrode, and an oscillation circuit included in the package. The oscillation circuit includes an amplifier and a resonator connected between an input node and an output node of the amplifier. The sensing terminal is connected to one of the input node and the output node of the amplifier. When a grounded second conductor approaches the first conductor, a second capacitance is formed between the first conductor and the second conductor, and the first capacitance and the second capacitance are connected in series between the sensing electrode and the ground so that an oscillation frequency of the oscillation circuit is changed.

Dependencies are inferred from the claim text.