| 摘要 |
PURPOSE:To detect a timing phase difference with the simple configuration of the titled circuit by operating two differential amplifiers alternately and connecting the positive and negative outputs mutually. CONSTITUTION:A PAM signal received from a terminal 21 and a signal passed through a delay circuit 33, which delays the PAM signal by 1 clock, are applied to two differential amplifiers consisting of transistors (TRs) 27, 28 and TRs 29, 30 respectively. These differential amplifiers are operated alternately by switch TRs 31 and 32 alternately operated by a timing oscillator, which is not shown in the drawing. A timing phase difference detecting signal for correctly controlling the oscillation frequency of the timing oscillator is outputted to an output terminal 24 which combines the positive and negative outputs of the differential amplifiers. The detecting signal is scarcely influenced by the deterioration of a received waveform, so that the invented circuit can be used also for deteriorated transmitting lines. |
