| 摘要 |
The PLL circuit in the disk drive, according to the present invention, is comprised of the following: a VCO (Voltage Controlled Oscillator) 11d, a frequency divider (DIV) 11e, a phase comparator (PC) 11a, a charge pump 11b, a low-pass filter (LPF) 11c, and a MIRR TE HOLD circuit 11f. Wherein, the LPF (Low-Pass Filter) 11c passes only low frequency components of the phase-error voltage, generated by the charge pump 11b, and provides the resulting, low frequency components passed, as a VCO control voltage, for the VCO. The phase comparator 11a compares the phase of a divided, VCO clock signal output from the frequency divider 11e, to that of an EFM signal. The divided, VCO clock signal results from the frequency-dividing of a VCO clock signal, which has been output from the VCO 11d, by the frequency divider 11e. The MIRR TE HOLD circuit 11f controls the charge pump 11b to half its own operation when the pick-up stays within a mirror region of the disk during the seeking operation of the pick-up, by outputting a PC HOLD signal to the charge pump 11b. The EFM signal results from converting a RF signal, which is picked up from a disk by the pick-up.
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