A novel low-cost, high efficiency, low-ripple high PF LED driver with ripple cancellation

Inhalt:
The standards and regulations have increasingly stringent requirement for light quality, which requires lower LED ripple current driver. This paper proposes a low-ripple high PF LED driver scheme using ripple cancellation concept to shorten effective power processing paths for high efficiency. Unidirectional converter is adopted as ripple canceler to compensate large ripple current of PFC output for low-cost and simple control. With proposed voltage following circuit, the driver can achieve high efficiency during full LED load range. Prototype experiments verified that the proposed scheme realized the same current ripple as 2-stage driver; similar cost and efficiency as 1-stage driver.