| 摘要 |
PURPOSE:To prevent phase deviation by controlling a phase shifter so as to set the phase of a clock signal at the center of a corresponding input NRZ signal after comparing the output of a differentiation circuit to extract the clock signal from the inputted NRZ signal with the output of a phase comparator to compare the phases of the input/output data in an identifying reproducing device. CONSTITUTION:This circuit is provided with a D-type flip-flop 3 to input the NRZ signal, differentiation circuit 5 and amplifier 7 to output the clock signal by amplifying the output of a narrow band filter 6 inputting the output of this differentiating circuit 5. The output of the amplifier 7 is outputted after controlling the phase by a phase shifter 11, and a phase comparator 9 is provided to find the difference between the phases of an input signal 1 and the output signal of the D-type flip-flop 3. Then, a phase controller 10 is provided to control the phase shifter 11 after comparing this output with the output of the differentiation circuit 5. In the phase controller 10, phase error is detected with the output of the differentiation circuit 5 as a reference signal, and the phase shifter 11 is controlled so as to correct the error. Thus, the phase of the identification clock is always set at the center of an identification input data. |
