LED brightness control for video display application

The technique is suggested for a kind of pulse-width-modulation LED dimming in LED video displays. The significant increase of the gray levels number and image refresh frequency can be achieved when the large number of LEDs is controlled serially. The need for a large number of grayscale levels and high refresh rate is explained. The controlling data flow and the amount of buffer memory are the same as with binary-weighted pulse-width-modulation. Spreading the switching pulses in time reduces the electromagnetic interference.