Patent ID: 8403233

Claim:
A semiconductor integrated circuit device comprising: an antenna terminal coupled to an antenna; a power supply circuit that generates power supply voltage from an alternating-current (AC) signal supplied from the antenna to the antenna terminal; and a receiver circuit that demodulates an information signal which is superimposed on the AC signal, wherein the receiver circuit comprises a rectifier circuit, a filter circuit, a capacitor, an amplifier, a feedback path, a switch circuit, a binarizing circuit, and a control circuit, wherein the rectifier circuit rectifies the AC signal supplied to the antenna terminal to smooth the AC signal, wherein the filter circuit is configured for an output signal of the rectifier circuit to be supplied to an input terminal of the filter circuit which reduces a high frequency component, wherein the amplifier is configured for an output signal of the filter circuit to be supplied to an inverting input terminal of the amplifier via the capacitor, wherein the amplifier has a function of inverting and amplifying an input signal supplied to the inverting input terminal with respect to a first reference voltage, wherein the inverting input terminal is configured for an output signal of the amplifier to be transmitted to the inverting input terminal via the feedback path and the switch circuit, wherein the switch circuit is configured to be controlled by an output signal of the control circuit, wherein the binarizing circuit binarizes the output signal of the amplifier, and wherein, in a lapse period of predetermined time since a level change in an output signal of the binarizing circuit, the switch circuit is controlled to an off state by the output signal of the control circuit.