Design of LED driver circuits with single-stage PFC in CCM and DCM

LED with constant output current and power factor correction are presented in this paper, the non-isolated Buck converters are used for the LED drivers, according to different operating mode of inductor current, power factor correction is realized with both of Voltage Follower Control under DCM and Nonlinear Carrier Control under CCM. NLC needn't the multiplier which is used in traditional power factor correction, therefore, the cost of system can be reduced. The designed circuits are verified by simulations of IsSpice software and practical experiments, these results show that the proposed approaches achieved the goal of higher PF and constant output current.