| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce undesired power consumption by providing a power-down means that reduces power of a synchronization pattern detection section for a prescribed period. SOLUTION: A 1st power-down control signal (h) is made inactive for a period after application of power before establishment of a synchronization pattern or after occurrence of out of synchronization till the establishment of the synchronization pattern so as to set a reference voltage (j) of a 1st control reference voltage generating section 6 to a usual value, the set reference voltage is fed to a current source of an ECL gate of a synchronization pattern detection section 1, which is operated normally. However, after the synchronization establishment resulting from detecting a first synchronization pattern, the 1st power-down control signal (h) is inactivated for the synchronization pattern period to set the reference voltage (j) to be a usual value and it is applied. The control signal (h) is activated for the other periods, the reference voltage (j) is set to a value lower than the usual value and it is applied to the current source of the ECL gate of the synchronization pattern detection section 1 so as to shut out the current consumed in the ECL gate thereby reducing the power of the synchronization pattern detection section 1.</p> |
