Power supply apparatus and method for providing voltage

A method for providing an output voltage to a load, comprising:

• providing a current;
• converting the current into the output voltage;
• detecting the current flowing through the load and generating a current detection result;
• and
• generating a control signal according to the current detection result and the output voltage, and controlling the amount of the current according to the control signal.

A power supply apparatus having an output terminal coupled to a load, wherein the power supply apparatus outputs an output voltage through the output terminal, the power supply apparatus comprising:

• a current modulation unit, for receiving an input voltage and a control signal and generating an output current, wherein the current modulation unit adjusts the amount of the output current according to the control signal;
• a voltage converting unit, coupled to the current modulation unit, for converting the output current into the output voltage;
• a current detector, coupled between the voltage converting unit and the output terminal, for detecting the current flowing through the load and outputting a current detection result;
• a determination circuit, coupled to the current detector and the output terminal, for determining the output voltage and the current detection result, and outputting a starting signal and a holding signal;
• a digital control unit, coupled to the determination circuit, for generating a digital signal according to the starting signal and the holding signal;
• and
• a digital to analog converter, coupled to the digital control unit and the current modulation unit, for converting the digital signal into the control signal.