Single Stage Offline LED Driver

摘要

A non-isolated soft-switched high power factor offline LED driver is introduced in the paper. The Buck-Boost converter is chosen for this application due to its simplicity and low cost. The converter operates with constant peak current for constant power control, and in transition mode (boundary mode between CCM and DCM) to achieve soft switching. High power factor is achieved by reshaping the peak current nearby the zero crossing of input AC line.