a lower - cost and more precise control methodology of regulating the output current of a flyback converter from the primary side is provided . the methodology regulates the output current accurately in both continuous current mode and discontinuous mode and can be applied to most small , medium , and high power applications such as cell phone chargers , power management in desktop computers and networking equipment , and , generally , to a wide spectrum of power management applications . two highly integrated semiconductor chips based on this control methodology are also described that require very few components to build a constant current flyback converter .