US Patent 10389223 Active clamp flyback converter control with reduced current

A method and controller for controlling a converter are provided. The converter is operated in a first phase in which controller logic asserts a first gate drive signal to cause a first transistor of the converter to be conductive and deasserts a second gate drive signal to cause a second transistor of the converter to be non-conductive. In a first deadtime phase and a second phase, the controller logic deasserts both the first and second gate drive signals to cause leakage energy from a leakage inductance of a primary winding of the converter to be transferred to a clamp capacitance of the converter. After the leakage energy is transferred, the converter is operated in a third phase in which the logic asserts the second gate drive signal and deasserts the first gate drive signal.