The LT3799 is a universal input, isolated LED controller with active power factor correction (PFC), specifically designed for driving LEDs from a universal input range of 90VAC to 265VAC. The LT3799 is compatible with standard TRIAC in-wall dimmers. A unique current sensing scheme delivers a well regulated (±5%) current to the secondary side without using an optocoupler. This not only enhances performance while reducing cost, but also improves reliability with the addition of open and shorted LED protection. The single stage PFC regulator design requires minimal external components and offers very low levels of harmonic distortion.