A switched mode power converter includes a switch, an energy transfer element coupled to the switch, and a controller that includes a delayed ramp generator coupled to generate a delayed ramp signal, an input charge control signal generator coupled to generate an input charge control signal representative of an integral of an input current sense signal and a ratio of an input voltage sense signal to an output voltage sense signal, and a drive signal generator coupled to receive the delayed ramp signal and the input charge control signal, to regulate an output of the switch mode power converter. The drive signal generator produces a drive signal responsive to the input charge control signal and the delayed ramp signal. The drive signal is coupled to control the switch of the switch mode power converter.