A Customized AC Hybrid LED Driver With Flicker Reduction for High Nominal Range Applications

This brief presents a customized ac hybrid LED driver for high nominal range (220–240 VAC) applications using average current control. A fixed offset hysteretic window approach is proposed to reduce the switching frequency variation. In order to enable low-side current sensing, a special substrate connection is presented. The designed LED driver is fabricated with a 0.18- $\mu \text{m}$ , 700-V ultra-high voltage CMOS process. Measurement results show that under 230-VAC, 50 Hz input, the peak efficiency of the customized design is over 94% and the power factor is greater than 0.92 while suppressing the photometric flicker and delivering 17-watt power to the LEDs.