| 摘要 |
A clock generating apparatus applicable to a sample servo type magnetic disk. A clock pattern regenerative signal z(t) is digitized by an A/D converter (33), and the resultant signal is supplied to a phase comparator (52). The linear coupling of N-pieces of sample values and N-pieces of weighting coefficients is subjected to inner product computation in a computing element (61) to obtain a phase comparison error signal f( theta ) from a D flip-flop (62). This signal f( theta ) is analoged in a D/A converter (53), and the resultant signal is supplied as a control signal to VCO (51) via a loop filter (54), the phase of a clock signal CLK from the VCO (51) being controlled to obtain a clock signal CLK synchronous with the regenerative signal z(t). When coefficients the sum of which becomes zero are used as weighting coefficients, a signal f( theta ) not influenced by DC component on which the regenerative signal z(t) is superposed, can be obtained, and a clock signal CLK synchronized with a high accurancy with the regenerative signal z(t) can be obtained.
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