Apparatus and method for charge control in wireless charging system

An electronic device for charge control, the electronic device comprising:

• a direct current-to-direct current (DC/DC) converter configured to step down a voltage level of a DC power outputted from a rectifier of the electronic device to a voltage level for a load of the electronic device and to step up an output voltage level of a DC power from the load to be greater than or equal to a supply voltage level for a power amplifier of the electronic device;
• and
• the power amplifier configured to convert a DC voltage stepped up by the DC/DC converter into an alternating current (AC) voltage and to amplify the converted AC voltage,
• wherein the DC/DC converter is further configured to step down the voltage level of the DC power outputted from the rectifier in a power receiving mode and to step up the output voltage level of the DC power from the load in a power transmitting mode,
• wherein the DC/DC converter comprises:
• a first capacitor connected to the power amplifier;
• a second capacitor connected to the load;
• and
• an output voltage determining unit configured to determine a voltage applied to the first capacitor to be an output voltage of the DC/DC converter in the transmitting mode, and to determine a voltage applied to the second capacitor to be an output voltage of the DC/DC converter in the receiving mode.