Integrated driver for power LEDs

This paper presents an off-line integrated full ballast to supply a 35W assembly of Power LEDs. The proposed solution is based in an input PFC stage and a DC to DC converter which provides a constant current through the assembly independently from the DC link voltage. The full ballast has full dimming capability, and all the analysis and design steps are presented, thus guaranteeing the fulfilling of the existing regulations. The novelty of the final solution comes from the simplicity and robustness of the control scheme in a compact power stage. A final prototype of the ballast has been built and tested, and experimental results are shown in the last part of the paper. Finally, conclusions and future developments are shown.