COMMUNICATION INTERFACE CIRCUIT AND COMMUNICATION EQUIPMENT

摘要

PPROBLEM TO BE SOLVED: To provide a communication interface circuit and communication equipment for suppressing the increase of a chip size and costs, and for satisfactorily maintaining the characteristics of pressure resistance of a clamp circuit, and for efficiently and accurately performing load modulation, and for accurately performing demodulation. PSOLUTION: The communication interface circuit includes: an antenna circuit 130 including a resonance circuit; a clamp circuit 103 for clamping an AC voltage to be induced between a first power supply terminal and a second power supply terminal through an antenna circuit to a fixed voltage according to a control signal; a full wave rectifier 105 for converting an AC voltage to be induced between the first power supply terminal and a second power supply terminal to a DC voltage; a pressure divider 107 for dividing the peak value of the DC voltage or the AC voltage by the rectifier; and a differential amplifier 108 for comparing the partial pressure voltage with reference voltage of the pressure divider, and for outputting the comparison result to the clamp circuit as a control signal. PCOPYRIGHT: (C)2010,JPO&INPIT