In a power converter, an input power source (98) is intermittently coupled to provide a current flow (Icoil) in consecutive cycles (T) to generate an output voltage (Vo). The coupling durations (Tp) are adjusted in conjunction with a cycle skip count (112CNT) which is the count of cycles in which no coupling occurs. In some embodiments, the adjustments are performed to keep the coupling durations near the maximum efficiency range (between TLOW and THIGH), and the skip count is adjusted at the same time to obtain the desired output voltage in the presence of load current variations. The coupling frequencies are kept in a desired range to avoid interference with other circuit elements.