Oscillating signal generating device and related method

An oscillating signal generating device, comprising:

• an oscillating circuit, comprising:
• a resonator, having a first terminal and a second terminal, for generating an oscillating signal;
• a resistive element, having a first terminal coupled to the first terminal of the resonator, and a second terminal coupled to the second terminal of the resonator;
• and
• an oscillating start-up circuit, having an input terminal coupled to the first terminal of the resonator, and an output terminal coupled to the second terminal of the resonator;
• and
• a control circuit, coupled to the resonator, for generating a control signal to change the oscillating start-up circuit into a disable mode from an enable mode when the oscillating circuit generates an oscillating output signal under an operation mode, and outputting the oscillating signal generated by the resonator as the oscillating output signal of the oscillating circuit;
• wherein the control circuit comprises:
• a peak-to-peak detector, for obtaining an amplitude of the oscillating output signal by detecting a peak-to-peak value of the oscillating output signal when the oscillating circuit is under the operation mode and when the oscillating start-up circuit is under the enable mode, and setting the control signal to change the oscillating start-up circuit into the disable mode from the enable mode when the peak-to-peak value reaches a first peak-to-peak threshold value, wherein no power is injected into the resonator when the oscillating start-up circuit enters the disable mode.