A controller for use in a power supply includes a drive signal generator, a jitter signal generator, a compensator signal generator, and an arithmetic operator. The drive signal generator is coupled to output a drive signal in response to an input signal. The jitter signal generator is coupled to provide a jitter signal that is representative of a first percentage amount to modulate a switching period of the drive signal. The compensator signal generator is coupled to provide a compensator signal responsive to the jitter signal, where the compensator signal is representative of a second percentage amount to change a duty ratio of the drive signal. The arithmetic operator adjusts the input signal of the controller in response to the compensator signal to provide a compensated input signal, where the duty ratio of the drive signal is adjusted by the second percentage amount in response to the compensated input signal.