Oscillator and self-calibration method thereof

An oscillator, comprising:

• an oscillation unit for generating an oscillation signal;
• a converting unit for converting frequency of the oscillation signal into a voltage signal;
• a comparison unit for comparing the voltage signal with a first voltage corresponding to a higher frequency and a second voltage corresponding to a lower frequency, and outputting a comparison result signal;
• an adjusting unit for storing a calibration value, adjusting the calibration value based on the comparison result signal and outputting a calibration signal corresponding to the adjusted calibration value;
• a calibration unit for calibrating the frequency of the oscillation signal based on the calibration signal;
• a control unit for generating a time window for calibration;
• and
• a latch unit for latching the calibration signal, wherein the calibration unit is configured to determine whether there is a time window for calibration, and if yes, the calibration unit calibrates the frequency of the oscillation signal based on the calibration signal, and if not, the latch unit latches the calibration signal.