Patent ID: 8542500

Claim:
A resonant power converting circuit, comprising: a resonant converting unit; a control unit, coupled to the resonant converting unit, the control unit outputting at least one first switching signal to the resonant converting unit so as to adjust an output voltage of the resonant converting unit, wherein the control unit is associated with a lowest switching frequency for limiting a frequency of the first switching signal; a current detecting unit, coupled to an output of the resonant converting unit, the current detecting unit detecting an output current of the resonant converting unit; and a frequency modulation unit, coupled to the current detecting circuit and the control unit, the frequency modulation unit adjusting the lowest switching frequency of the control unit in response to the output current and comprising a first resistor coupled between a frequency setup terminal of the control unit and a ground terminal; and a first modulation unit coupled to the current detecting unit and the frequency setup terminal of the control unit; wherein the lowest switching frequency of the control unit is increased by the frequency modulation unit when the output current exceeds a predetermined current value.