| 摘要 |
<p>PURPOSE:To extend the service life of a noncontact IC card is practical use by providing a modulation means which modulates a signal from a data processing means to process data demodulated by a selected demodulation signal out of the signals of first and second demodulation means and outputs it to an antenna means, and a battery to supply a power source to every means. CONSTITUTION:An antenna circuit 16, the battery 17, and a crystal resonator 19 are connected to an IC 10. When a CPU 11 judges that a start-up method using a demodulation circuit 26 is selected, a transistor 106 is cut off, and a sleep mode is set, and a signal of 'H' level is outputted from an AND gate 111 to an AND gate 108, therefore, trigger reception by a CMOS inverter 102 can be performed. Meanwhile, when the CPU judges that the start-up method not using the demodulation circuit 26 is selected, both the AND gates 107 and 108 are cut off, and the demodulation circuit 26 stops an operation. Thereby, it is possible to extend the service life of the card in practical use by suppressing the consumption of the power source in nonuse.</p> |
