A control circuit for an optical disk drive includes a frequency detector,
a phase detector, a low pass filter, a voltage-controlled oscillator
(VCO), and a controller. The frequency detector and the phase detector
both receive an eight-to-fourteen modulation (EFM) signal and a data
phase-locked loop (DPLL) signal. The controller can calculate a target
frequency and control the VCO to output the DPLL signal according to the
target frequency. During a non-seek mode, the VCO outputs the DPLL signal
according to output of the frequency detector, phase detector, and low
pass filter. During a seek mode or when spindle speed of the optical disk
drive changes, the VCO outputs the DPLL signal according to the target
frequency. The controller further outputs charge pump currents for the
frequency detector and the phase detector and sets an RF equalizer signal
and a differential phase detector (DPD) equalizer signal according to the
target frequency.