DIGITAL PLL DEVICE FOR USE IN DISC PLAYBACK APPARATUS OR THE LIKE FOR IMPLEMENTING NEW ALGORITHM ACHIEVING HIGH-SPEED PLAYBACK AND HIGH PLAY-ABILITY

摘要

PURPOSE: A digital PLL(Phase Locked Loop) device is provided to obtain a low operating frequency equivalent to an operating frequency of an analog PLL and perform a high-speed playback operation by using a 16-phase and 2-terminal voltage controlled oscillator. CONSTITUTION: A digital PLL includes a clock generating unit, a 16-phase and 2-terminal VOC(10), a pulse-length measuring unit, and a run-length data extracting unit. The clock generating unit is used for generating a reference clock on the basis of a binarized reproduction signal and a frequency of run-length data, and for generating N-phase clocks using the reference clock. The pulse-length measuring unit(2) is used for measuring a pulse length of the binarized reproduction signal by using the N-phase clocks to output pulse-length data. The run-length-data extracting unit is used for counting the pulse-length data on the basis of a virtual channel clock to extract run-length data.