A method comprises providing a resonant converter, wherein the resonant converter comprises an input switch network coupled to a power source, wherein the input switch network comprises a plurality of power switches, a resonant tank coupled to the plurality of power switches, a transformer coupled to the resonant tank and an output stage coupled to the transformer, wherein the output stage comprises a synchronous rectifier formed by a first switch and a second switch, detecting a drain voltage of the first switch, comparing the drain voltage with a predetermined voltage threshold, wherein the drain voltage is coupled to a negative input of a comparator and the predetermined voltage threshold is coupled to a positive input of the comparator, generating a logic state based upon an output of the comparator and adjusting, by a control circuit, a switching frequency of the resonant converter based upon the logic state.