Patent ID: 7539028

Claim:
A switching regulator circuit, comprising: a switch to be coupled to an energy transfer element of a power supply; a feedback circuit coupled to receive a feedback signal from an output of the power supply; a controller coupled to the switch and to the feedback circuit to control a switching of the switch to selectively regulate an output voltage over a range of output currents and selectively regulate an output current over a range of output voltages at the output of the power supply, the controller further including a fault timer to measure a duration of an absence of an adequate feedback signal, wherein the controller further includes a fault mode of operation and a feedback check mode of operation, the fault mode of operation to substantially reduce an average power at the output of the power supply when the feedback signal is absent longer than a fault time, the feedback check mode of operation to substantially raise the average power at the output of the power supply by raising the switching frequency from the first switching frequency to the second frequency before expiration of the fault time such that the substantially raised output power drives the output current or output voltage into a regulated region to reestablish the adequate feedback signal.