A controller for use with a power converter including a switch configured to conduct to provide a regulated output characteristic at an output of the power converter, and method of operating the same. In one embodiment, the controller includes a linear control circuit, coupled to the output, configured to provide a first control signal for the switch as a function of the output characteristic. The controller also includes a nonlinear control circuit, coupled to the output, configured to provide a second control signal for the switch as a function of the output characteristic. The controller is configured to select one of the first and second control signals for the switch in response to a change in an operating condition of the power converter.