Comparative analysis of basic single-stage non-isolated AC-DC topologies employed as high-current COB LED drivers

This work presents a comparative study comprising the traditional single-stage buck and buck-boost rectifiers used as high-current COB (chip-onboard) LED (light emitting diode) drivers. The structures are designed both in continuous conduction mode (CCM) and discontinuous conduction mode (DCM) in order to analyze the existing stresses in the semiconductors and overall efficiency. For this purpose, a high-current COB LED is used while driven by the aforementioned single-stage non-isolated topologies. The drivers are supposed to present essential features when dealing with outdoor floodlighting e.g. high power factor and low harmonic distortion of the input current. Besides, simulation tests are performed using real intrinsic parasitic parameters of commercially available semiconductors. Finally, the results are properly discussed to evaluate the restrictions of these basic non-isolated high-current COB drivers.