A Highly Accurate Current LED Lamp Driver With Removal of Low-Frequency Flicker Using Average Current Control Method

Abstract

This paper presents an average current control method for a light-emitting diode (LED) lamp driver that achieves a highly accurate current and removes low-frequency light flicker. The proposed LED lamp driver accurately maintains an average LED forward current by precisely adjusting the duration of the on- and off-times of the LED lamp driver. It also removes the low-frequency flicker by regulating the LED forward current without being affected by the low-frequency component of the ac line voltage. In addition, it reduces power consumption by eliminating the necessity of a high-voltage sensor or a high-side resistor, which causes conduction loss. The proposed average current controller was fabricated using a 0.18 mu m bipolar, complementary metal-oxide-semiconductor, and double diffused metal-oxidesemiconductor process technology. The measurement results of the proposed LED lamp driver show that the variation in the average LED forward current is less than 0.6%, and the light flicker below 120 Hz is completely removed. In addition, the measured maximum power efficiency and power factor of the proposed LED lamp driver are 89.22% and 0.93, respectively.