Patent ID: 8077484

Claim:
A controller for use in a power converter, comprising: a drive circuit to generate a switching signal coupled to be received by a power switch to be coupled to an energy transfer element and an input of the power converter to control a transfer of energy from the input of the power converter to an output of the power converter; and an output voltage sensor coupled to the drive circuit and coupled to receive a feedback signal representative of the output of the power converter, the output voltage sensor including first and second pulse sampler circuits, the first pulse sampler circuit coupled to capture a first peak voltage representative of a second peak of a ringing voltage of the feedback signal at a first time in the feedback signal, the second pulse sampler circuit coupled to capture a second peak voltage representative of the second peak of the ringing voltage of the feedback signal at a second time in the feedback signal, the output voltage sensor coupled to output a change signal to the drive circuit in response to the first and second peak voltages.