Patent ID: 8681519

Claim:
A power factor correction system (PFC) for generating an output voltage from an input voltage, the PFC system comprising: an input for receiving the input voltage; an output for outputting the output voltage; a first power rail coupled to the input and the output to receive the input voltage and generate the output voltage, the first power rail including a first switch and a first inductor having a first inductance value; a second power rail coupled to the input and the output, the second power rail selectively operable to generate the output voltage, the second power rail including a second switch and a second inductor having a second inductance value; a controller coupled to the input, the controller configured to detect a magnitude of the input voltage, to generate a first control signal to control switching of the first switch, to generate a second control signal to control switching of the second switch when the magnitude of the input voltage is less than or equal to a nonzero threshold value, and to not generate the second control signal when the magnitude of the input voltage exceeds the threshold voltage.