A power supply includes a controller integrated circuit that controls a switching operation of a primary switch based on a feedback voltage indicative of an output voltage of the power supply. The controller integrated circuit starts the switching of the primary switch when the feedback voltage reaches a first threshold voltage and stops the switching of the primary switch when the feedback voltage reaches a second threshold voltage. The controller integrated circuit adjusts the feedback voltage relative to the first threshold voltage to reduce the delay time to start switching the primary switch to increase the output voltage in response to changing load conditions.