A LED driving circuit includes a power factor correction circuit receiving a rectified mains voltage and providing output to a DC voltage bus, a string of LEDs connected in series, a voltage converter receiving input from the DC voltage bus and providing output to the string of LEDs, and a microcontroller. The microcontroller receives a plurality of digital feedback signals from the voltage converter, controls the voltage converter based upon a user desired brightness level and the plurality of digital feedback signals, and receive a plurality of feedback signals from the power factor correction circuit. Based on the plurality of feedback signals, the microcontroller operates the power factor correction circuit in transition mode where the user desired brightness level is above a threshold brightness, and operates the power factor correction circuit in discontinuous mode where the user desired brightness level is below the threshold brightness.