a ccfl power converter circuit is provided using a high - efficiency zero - voltage - switching technique that eliminates switching losses associated with the power mosfets . an optimal sweeping - frequency technique is used in the ccfl ignition by accounting for the parasitic capacitance in the resonant tank circuit . additionally , the circuit is self - learning and is adapted to determine the optimum operating frequency for the circuit with a given load . an over - voltage protection circuit can also be provided to ensure that the circuit components are protected in the case of open - lamp condition .