a switch for wireless power transmission;

an SR-latch being applied with SET and RESET signals at an on/off timing of the switch and driving the switch;

a digital feedback-based compensator comparing magnitudes of an input AC voltage and a ground voltage at the on/off timing of the switch, and outputting a digital modulation value according to the magnitude difference;

a coarse delay line receiving an initial pulse according to the input AC voltage, and outputting a first pulse delayed by increasing a delay of the initial pulse in units of a first delay according to the digital modulation value;

a fine delay line finely adjusting the delay of the first pulse in units of a second delay smaller than the first delay unit when the input AC voltage becomes equal to the ground voltage according to the delay done by the coarse delay line;

a mode controller determining an operation time of the switch by controlling the fine delay line to consecutively adjust the delay of the first pulse; and

a pulse selector selecting a pulse at the operation time of the switch and inputting the selected pulse into the SR-latch.