Patent ID: 8325498

Claim:
An integrated circuit for use in a power supply, the integrated circuit comprising: a drive signal generator configured to generate a drive signal in response to a clock signal to control switching of a switch included in the power supply; a short on time detector coupled to the drive signal generator to provide an output indicating that consecutive on times of the drive signal are short on times, wherein an on time of the drive signal is a short on time if a switch current of the switch exceeds a current limit after a leading edge blanking period and if the on time of the switch is less than or equal to a sum of the leading edge blanking period and a current limit delay time period; and an oscillator configured to generate the clock signal, wherein the oscillator changes a frequency of the clock signal from a first frequency to a lower second frequency in response to the output of the short on time detector indicating that consecutive on times of the drive signal are short on times to delay a next switching period of the drive signal after the consecutive short on times.