A controller for use in a power supply regulator is disclosed. One controller includes a feedback circuit coupled to generate a feedback current signal that corresponds to a peak switching current in response to a sense signal from a power supply regulator output. A comparator is coupled to compare the feedback current signal with a reference voltage. A modulation circuit is coupled to the feedback circuit to generate a pulse width modulated switching signal with fixed switching frequency in response to the feedback current signal and the reference voltage. A multi-cycle modulator circuit is coupled to the output of the comparator. The multi-cycle modulator circuit is coupled to enable or disable a switch signal from the controller to be coupled to a switch of the power supply regulator. A group of two or more consecutive switching cycles is separated from a next group having two or more switching cycles by a time of no switching. The time of no switching is adjusted in closed loop to regulate a transfer of energy from a power supply regulator input to the power supply regulator output.