Power delivery device and control method thereof

A power delivery device, comprising:

• an output voltage control circuit, configured to control an output voltage of the power delivery device, to selectively switch the output voltage at one of a plurality of voltage levels;
• and
• a power factor correction circuit, configured to increase a power factor of the power delivery device;
• wherein when the voltage level of the output voltage is smaller than a predetermined level, the output voltage control circuit outputs a first disable signal to turn off the power factor correction circuit.

A control method, comprising:

• controlling, by an output voltage control circuit, an output voltage of a power delivery device selectively at one of a plurality of voltage levels;
• increasing, by a power factor correction circuit, a power factor of the power delivery device;
• and
• turning off the power factor correction circuit when the voltage level is controlled to be smaller than a predetermined level by the output voltage control circuit.