| 摘要 |
PURPOSE: To improve the reliability of a communication system by setting optimizingly a reference voltage for data demodulation in response to a level of a received input signal so as to allow the circuit to be in response to fluctuation of ambient environment. CONSTITUTION: A signal B obtained by applying envelope detection to an input received signal A at an envelope detector 2 is given to a peak hold means 5, in which the peak level is held and provides the output of a reference voltage Vref. A comparator 3 compares a detection signal B and the reference voltage Vref and gives a signal D obtained by applying arithmetic processing to a data signal C by a control circuit 6 to the peak hold means 5. Thus, the peak hold means 5 acquires a peak voltage being a detection output at that point of time and a detection signal is demodulated into a digital data signal C based on the reference voltage and optimum data demodulation is conducted by coping flexibly with a change/fluctuation in the transmission line and the ambient environment. |
