Design of an Energy Efficient Buck Based LED Driver in DCM and CCM

It is the design criteria of driving LEDs at constant current and keeping the input current’s harmonics low, attaining a high power factor, and maximizing efficiency. For low power general purpose lighting buck converter can be chosen for simplicity and reduced cost. It is a difficult to improve power quality parameter like, the THD (total harmonic distortion) and power factor of ac mains. In the proposed topology, the operation for high power factor and low THD at the AC mains’ input is accomplished through buck converter operation in both discontinuous conduction mode (DCM) and continuous conduction mode (CCM) with a suitable control circuit. This paper assures constant current in both cases for suitable design of control circuit. Over voltage protection has been incorporated. To validate the LED driver circuit, simulation studies are carried out.