| 摘要 |
PURPOSE:To extract a clock timing of a signal whose transmission speed differs with one timing extract circuit by providing plural resonance characteristics corresponding to each of plural transmission speeds to a filter means. CONSTITUTION:A differentiation circuit 421 detects a rising, falling timing of an NRZ(non return to zero) signal fed from a matrix switch section and outputs it as a discontinuous clock signal and gives it as a SAW filter 422 to convert the signal into a continuous sinusoidal wave signal. Moreover, in order to obtain a reproduction clock signal of a logic level, the sinusoidal wave signal is fed to a sinusoidal wave/rectangular wave conversion circuit 423, in which the signal is converted into a rectangular wave signal. When a control signal representing the operation inhibit of a timing extract circuit 42 is applied externally, a switch 41 is operated not to apply an undesired NRZ signal to the SAW filter 422 and the switch 43 is operated so as not to output an undesired reproduction clock signal. |
