A switching regulator control circuit comprises a first control circuit to control conduction of the switch according to a first mode of operation and having a regulation point and a second control circuit to control conduction of the switch according to a second mode of operation in response to a reference signal that is calibrated to have a predetermined relationship with respect to the regulation point of the first control circuit. In some embodiments, the reference signal is calibrated to be a predetermined amount greater than the regulation point of the first control circuit and may be calibrated during the first mode of operation or in response to a regulator start or restart event.