The WD15-S30A is an AC Direct LED Driving IC with internal 4 steps. It can drive several series LEDs from rectified AC voltage. It will give much convenience to the design because it requires a small number of external components. The WD15-S30A has higher LED current driving capability and its current can be adjustable with external resistors. The WD15-S30A will help engineers to produce excellent products in LED lightings for energy efficiency, design efficiency, cost efficiency, and so on.