Cxle8447 is a single-stage, source power factor correction, high-precision primary side feedback led constant current control chip, which is suitable for flyback isolation or non isolation LED constant current power supply with 85vac-265vac full range input voltage. Cxle8447 integrated active power factor correction circuit can achieve high power factor and low total harmonic distortion. Due to the critical continuous mode of inductor current, the power MOS transistor is in the zero current on state, the switching loss can be reduced, and the utilization ratio of transformer is also high. Cxle8447 adopts a special current sampling mechanism, which works in the original side feedback mode. Without secondary feedback circuit, it can achieve high-precision output constant current control, save system cost and volume, and improve system reliability. Cxle8447 adopts patented line voltage and load compensation technology to achieve excellent line voltage regulation and load regulation. The line voltage compensation coefficient can also be flexibly adjusted by external components. Cxle8447 has built-in multiple protection functions to enhance the system reliability, including LED open circuit protection, led short circuit protection, chip power supply over-voltage protection, under voltage protection, current sampling resistance open circuit protection and cycle by cycle current limiting.