Charge control circuit using battery voltage tracking, and a device having the same

A device comprising:

• a rectifier circuit configured to rectify an alternating current (AC) signal into a direct current (DC) signal, and to output the DC signal as an input voltage;
• and
• a charge control circuit configured to output a charging voltage based on the input voltage, and to control the input voltage,
• wherein the input voltage tracks the charging voltage.

A charge control circuit configured to supply a charging voltage to a battery, comprising:

• an input terminal configured to receive an input voltage from a rectifier circuit;
• and
• an output terminal connected to the battery,
• wherein the charge control circuit is configured to control the input voltage, and
• the input voltage tracks the charging voltage.

A device comprising:

• an antenna;
• a battery;
• a rectifier circuit configured to rectify an alternating current (AC) signal into a direct current (DC) signal, and to output the DC signal as an input voltage;
• a charge control circuit configured to output a charging voltage based on the input voltage, and to control the input voltage;
• a matching circuit connected to the antenna;
• a communication circuit configured to perform wireless communication with an external device through the antenna;
• and
• a control circuit configured to control the rectifier circuit and the communication circuit to control wireless charging,
• wherein the input voltage tracks the charging voltage.