Patent ID: 8829875

Claim:
A controller for use in a power supply, the controller comprising: a drive signal generator coupled to output a drive signal having a switching period and a duty ratio to control switching of a switch in response to an input signal to regulate an output of the power supply, the switch to be coupled to the controller; a jitter signal generator coupled to provide a jitter signal, wherein the switching period of the drive signal varies in response to the jitter signal, and wherein the jitter signal is representative of a first percentage amount to modulate the switching period of the drive signal; a compensator signal generator coupled to provide a compensator signal responsive to the jitter signal, wherein the compensator signal is representative of a second percentage amount to decrease the duty ratio in response to the jitter signal increasing the switching period of the drive signal; and an arithmetic operator coupled to adjust the input signal of the controller in response to the compensator signal to provide a compensated input signal, wherein the drive signal generator is coupled to adjust the duty ratio of the drive signal by the second percentage amount in response to the compensated input signal.