OVERVOLTAGE PROTECTION CIRCUIT, POWER TRANSMISSION DEVICE INCLUDING THE SAME, AND CONTROL METHOD THEREOF

摘要

Provided is a power transmission device including a transmission unit and a reception unit. The reception unit includes an overvoltage protection circuit and provides a feedback signal to the transmission unit. The transmission unit controls intensity of power wirelessly transmitted to the reception unit with reference to the feedback signal to control power consumption of the overvoltage protection circuit. The overvoltage protection circuit includes a detection unit and a current control unit. The detection unit detects an input voltage and a first current to generate a control signal. The current control unit controls a second current with reference to the control signal. Herein, the second current is controlled so that a ratio of the input voltage to a sum of the first and second currents is kept constant.