Primary-side feedback flyback LED controller with tight current regulation

DUAN Ling-xiao，MENG Jian-yi

（School of Electrical Engineering，Zhejiang University，Hangzhou 310027，China）

Abstract：Aiming at home lighting LED driver international standards and most low power level LED drivers without power factor correction，LED drivers with power factor correction，high-precision constant current control and compensation of sample errors were researched. Constant current control methods for home LED lighting were summarized. A system which samples primary peak current and magnetic reset time was presented. After calculation of the signals mentioned above，drive signal to control power MOSFET can be generated. The results indicate that when the input line voltage is 220 V，the average output current 353 mA with 7 W led as load，and

the efficiency is 82% and power factor can reach 0.94；the output current error can be less than 5% and minimum power factor can be 0.92 with the input voltage from 85 V~265 V.