Patent ID: 8248040

Claim:
An interleaved power factor correction (PFC) converter comprising: a rectifier circuit for converting an alternating current (AC) voltage to a rectified input voltage; a first power factor correction (PFC) sub-circuit having a first inductor and a first switching device, the first inductor connected to store energy provided by the rectified input voltage when the first switching device is ON and to discharge stored energy to a direct current (DC) output when the first switching device is OFF; a second power factor correction (PFC) sub-circuit connected in parallel with the first PFC sub-circuit and having a second inductor and a second switching device, the second inductor connected to store energy provided by the rectified input voltage when the second switching device is ON and to discharge stored energy to the DC output voltage when the second switching device is OFF; and a controller that provides gate drive signals to the first switching device and the second switching device to define ON and OFF times of each switching device to ensure operation of the interleaved PFC converter in a discontinuous conduction mode (DCM), the controller configured to operate in a normal mode in which OFF times of each switch are based on the rectified input voltage and the DC output voltage, and to operate in a time-limiting mode (TLM) in which OFF times of each switch are limited by detected near zero crossings of a monitored sum of inductor currents.