Apparatus and method for charge control in wireless charging system

The apparatus of claim 29, wherein the integrated DC/DC converter comprises:

• a first capacitor connected in parallel to at least one of the AC/DC converter and the power amplifier;
• a second capacitor connected in parallel to the load;
• a first transistor of a P-channel metal oxide semiconductor (PMOS) type, the first transistor connected in series to the first capacitor;
• a second transistor of an N-channel metal oxide semiconductor (NMOS) type, the second transistor connected in parallel to the first transistor;
• an inductor connected in series to the second transistor;
• and
• an output voltage determining unit configured to determine a voltage applied to the second capacitor to be an output voltage of the integrated DC/DC converter in the receiving mode, and to determine a voltage applied to the first capacitor to be an output voltage of the integrated DC/DC converter in the transmitting mode.

The apparatus of claim 29, wherein the load comprises:

• a battery charger configured to charge a battery by storing the DC voltage stepped down by the integrated DC/DC converter;
• the battery configured to be charged by the battery charger in the receiving mode, and to transfer a DC voltage to the integrated DC/DC converter in the transmitting mode;
• and
• a first switch unit configured to connect the battery charger to the battery in the receiving mode, and to break the connection between the battery charger and the battery and connect the integrated DC/DC converter to the battery in the transmitting mode.

An apparatus for charge control the apparatus comprising:

• a rectification unit configured to convert an alternating current (AC) power received wirelessly into a direct current (DC) power, in a receiving mode;
• a first DC-to-DC (DC/DC) converter configured to step down a voltage level of the DC power to a voltage level required by a load in the receiving mode;
• a second DC/DC converter configured to step up an output voltage level of the load to be greater than or equal to a supply voltage level set in a power amplifier in a transmitting mode;
• and
• the power amplifier configured to convert the DC voltage stepped up by the second DC/DC converter into an AC voltage based on a resonant frequency, and to amplify the converted AC voltage, in the transmitting mode.

A method for charge control, the method comprising:

• converting an alternating current (AC) power received wirelessly into a direct current (DC) power, in a receiving mode;
• stepping down a voltage level of the DC power to a voltage level required by a load, using an integrated direct current-to-direct current (DC/DC) converter in the receiving mode;
• stepping up an output voltage level of the load to be greater than or equal to a supply voltage level set in a power amplifier, using the integrated DC/DC converter in a transmitting mode;
• and
• converting the stepped up output voltage level into an AC voltage based on a resonant frequency, and amplifying the converted AC voltage, in the transmitting mode.

An apparatus for charge control, the apparatus comprising:

• a resonator configured to receive a power a receiving mode, transmit the power in a transmitting mode, and transfer an input power to another terminal by reflecting the input power in a relay mode;
• an integrated direct current-to-direct current (DC/DC) converter configured to step down a voltage level of a direct current (DC) signal output from an alternating current-to-direct current (AC/DC) converter to a voltage level required by a load in the receiving mode, and to step up a voltage level output from the load to be greater than or equal to a supply voltage level set in a power amplifier in the transmitting mode;
• and
• a controller configured to control the apparatus for charge control to operate in one of the receiving mode, the transmitting mode, and the relay mode, and increase an input impedance of the resonator to be greater than or equal to a predetermined value.

An apparatus for charge control, the apparatus comprising:

• a resonator configured to receive a power in a receiving mode, and reflect an input power in a relay mode;
• a direct current-to-direct current (DC/DC) converter configured to step down a voltage level of a direct current (DC) signal output from an alternating current-to-direct current (AC/DC) converter to a voltage level required by a load in the receiving mode;
• and
• a controller configured to control the apparatus for charge control to operate in one of the receiving mode, a transmitting mode, and the relay mode, and increase an input impedance of the resonator to be greater than or equal to a predetermined value.

An apparatus for charge control, the apparatus comprising:

• a resonator configured to transmit a power in a transmitting mode, and reflect an input power in a relay mode;
• a direct current-to-direct current (DC/DC) converter configured to step up a voltage level output from a load to be greater than or equal to a supply voltage level set in a power amplifier in the transmitting mode;
• and
• a controller configured to increase an input impedance of the resonator to be greater than or equal to a predetermined value in the relay mode.