A single-stage driver for high power LEDs

This paper proposes a single-stage driver for high-power light-emitting diodes (LEDs). The presented circuit combines an active power-factor-correction (PFC) converter with a half-bridge-type LLC resonant converter. The active PFC converter consists of two boost-converted cells to achieve input current shaping with interleaving methods. The halfbridge-type LLC resonant converter is designed for obtaining soft-switching on two power switches to reduce their switching losses. The proposed driver features cost-effectiveness, low levels of input current ripple, low switching losses, high power factor, fewer components and reduced leakage current. Finally, a prototype driver with current-equalizing function is developed to supply 140W high-power LEDs with a 110V utility-line input voltage. Simulation and experimental results demonstrate the feasibility of the proposed circuit.