Indirect current detection method for active switch control in a low-power Flyback converter

This paper proposes an indirect method for the detection of secondary winding current in a low-power flyback converter, based on the sensing of the output capacitor voltage ripple. The main goal of this method is to improve the overall conversion efficiency of the flyback converter by enabling the use of an active secondary switching device, while providing a solution that could be easily implemented in the form of an ASIC circuit targeting a standard low-voltage CMOS technology node.