摘要 |
A phase-locked loop apparatus for deriving clock pulses from return-to-zero data pulses is disclosed. It includes a phase detector for computing the difference, in time, between that portion of a detected data pulse which occurs before a clock pulse edge and the portion after the clock pulse edge. The difference, once computed, is held for a long period thereafter and is used to drive a voltage controlled oscillator. The voltage controlled oscillator generates the clock pulses which are applied to the phase detector and which comprise the output of the apparatus.
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