A method, adopted by a flyback converter circuit including a transformer, comprising: determining an output voltage (Vout) output from a secondary circuit of the transformer; feeding a feedback voltage (VFB) based on the output voltage from the secondary circuit back to a primary circuit of the transformer; and characterized by : increasing a current limit (Ilim) and a switching frequency (Fsw) of a primary current (IP) with the feedback voltage; supplying the primary current (IP) to a primary winding (W1) of the transformer; when the feedback voltage is less than a first threshold voltage (Vctlp), maintaining the switching frequency to be substantially constant while increasing the current limit with the feedback voltage; when the feedback voltage exceeds the first threshold voltage (Vctlp), increasing the current limit and the switching frequency of the primary current with the feedback voltage; and when the feedback voltage exceeds a second threshold voltage (Vcp), maintaining the current limit to be substantially constant while increasing the switching frequency with the feedback voltage, wherein the second threshold voltage exceeds the first threshold voltage (Vctlp), characterized by : when the feedback voltage exceeds a third threshold voltage (Vfp), maintaining both the current limit and the switching frequency to be substantially constant, wherein the third threshold voltage (Vfp) exceeds the second threshold voltage (Vcp). determining an output voltage (Vout) output from a secondary circuit of the transformer; feeding a feedback voltage (VFB) based on the output voltage from the secondary circuit back to a primary circuit of the transformer; and characterized by : increasing a current limit (Ilim) and a switching frequency (Fsw) of a primary current (IP) with the feedback voltage; supplying the primary current (IP) to a primary winding (W1) of the transformer; when the feedback voltage is less than a first threshold voltage (Vctlp), maintaining the switching frequency to be substantially constant while increasing the current limit with the feedback voltage; when the feedback voltage exceeds the first threshold voltage (Vctlp), increasing the current limit and the switching frequency of the primary current with the feedback voltage; and when the feedback voltage exceeds a second threshold voltage (Vcp), maintaining the current limit to be substantially constant while increasing the switching frequency with the feedback voltage, wherein the second threshold voltage exceeds the first threshold voltage (Vctlp), increasing a current limit (Ilim) and a switching frequency (Fsw) of a primary current (IP) with the feedback voltage; supplying the primary current (IP) to a primary winding (W1) of the transformer; when the feedback voltage is less than a first threshold voltage (Vctlp), maintaining the switching frequency to be substantially constant while increasing the current limit with the feedback voltage; when the feedback voltage exceeds the first threshold voltage (Vctlp), increasing the current limit and the switching frequency of the primary current with the feedback voltage; and when the feedback voltage exceeds a second threshold voltage (Vcp), maintaining the current limit to be substantially constant while increasing the switching frequency with the feedback voltage, wherein the second threshold voltage exceeds the first threshold voltage (Vctlp), characterized by : when the feedback voltage exceeds a third threshold voltage (Vfp), maintaining both the current limit and the switching frequency to be substantially constant, wherein the third threshold voltage (Vfp) exceeds the second threshold voltage (Vcp). <EOS>