Abstract: A calibration method for a vibration module includes transmitting a plurality of vibration signals corresponding to a plurality of vibration frequencies to the vibration module and detecting a plurality of input currents or input power levels of the vibration module corresponding to the plurality of vibration frequencies; and determining a vibration point of the vibration module according to the plurality of input currents or input power levels.

Abstract: A clock recovery circuit capable of automatically adjusting the frequency range of a voltage-controlled oscillator (VCO). The clock recovery circuit includes a phase detector, a charge pump, a loop filter, a voltage-controlled oscillator, a frequency counter, and a frequency control unit. The phase detector receives an input signal, such as EFM clock, and a VCO clock and outputs a control signal according to phase differences between the EFM clock and the VCO clock. The charge pump controls the charge action according to the control signal. The loop filter is connected to the charge pump and outputs a voltage signal. The voltage-controlled oscillator receives the voltage signal from the loop filter and outputs the VCO clock. The frequency counter counts the frequency of the VCO clock and outputs an oscillation frequency.