CAPACITIVE COUPLING CIRCUIT DEVICE PROVIDED WITH CAPACITIVE COUPLING CIRCUIT DEMODULATING MODULATED SIGNAL TRANSMITTED THROUGH COUPLING CAPACITOR

A capacitive coupling circuit device is provided with a capacitive coupling circuit and a ground-side feedback circuit. The capacitive coupling circuit demodulates a modulated signal, which is obtained by modulating an input signal and transmitting a modulated input signal through a coupling capacitor. The ground-side feedback circuit is inserted between a first ground terminal on a signal input side of the capacitive coupling circuit and a second ground terminal on a signal output side of the capacitive coupling circuit. The ground-side feedback circuit is configured by connecting a second capacitor in series to a parallel circuit of a first capacitor and a first resistor. Alternatively, the ground-side feedback circuit may be configured by connecting the second capacitor and a third capacitor in series to both ends of the parallel circuit of the first capacitor and the first resistor, respectively.