| 摘要 |
PROBLEM TO BE SOLVED: To obtain a demodulating method or demodulating circuit, which allows portable information equipment making synchronous electromagnetic induction communications by using a coil to stably receive signals, even if the electromagnetic coupling characteristics of a reception coil or the frequency characteristics of a receiving circuit are deviated. SOLUTION: In a method for demodulating data, the waveform of the received synchronous signals of a coil is shaped by means of a waveform shaping circuit using the midpoint of the signals as a threshold, and the level of the waveform, which is shaped when a predetermined time has elapsed from the rise or fall of the waveform is latched by using a demodulating clock which is faster than a transmitting clock. The received data are ultimately demodulated by discriminating the validity/invalidity of the latched data by performing due process steps.
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