| 摘要 |
PURPOSE:To extract a timing signal stably even when an input signal contains no timing signal, by discriminating the input data signal by an extraction timing signal, and compensating the frequency of a timing oscillator by compensation information obtained from the input signal when the discrimination output is 1. CONSTITUTION:A discriminating circuit 6 discriminates the timing signal in the input data signal to output a regenerated data signal to an output terminal 7. Further, a phase comparator 8 and a phase shift detector 9 detect positive or negative voltage variation corresponding to the phase difference between the input signal and extracted timing signal to apply the result to an operational amplifier 14 through a delay circuit 10 and an analog switch 11. The output of this amplifier 14 is applied to a VCD15 and also applied to a timing signal stability deciding circuit 16, and an AND circuit 17 ANDs the output of the circuit 16 and that of the circuit 6. Then, a switch 11 is closed when the timing signal is stabilized to output the stable timing signal to a terminal 5 through the VCD15. |
