| 摘要 |
<p>PURPOSE:To prevent noise or jitter from appearing at the output of synchronizing recovery independently of the presence of a signal input by providing a circuit identifying and reproducing an input signal, an extraction section extracting a clock from the input signal and a detection section detecting the presence of the input signal. CONSTITUTION:With an input signal given, a clock extraction section 10 acts like extracting a clock from a given input signal only, and when no input signal is in existence, an identification recovering section 1 identifies and recovers the input signal. A clock extraction section 10 is extracted from the input signal. A signal input detection section 11 detects the presence of the input signal and gives a detection signal to replacing AND gates G1 - G3. Then the switch timing of the AND gates G1, G2 is opposite to the timing of the switching of the gate G3. Thus, an output of the extraction section 10 is given to the gate G3 via a feedback circuit 9 and the required timing clock is obtained by the self-running oscillation due to the feedback of the output of the extraction section 10.</p> |
