National Semiconductor recently announced some new chips for Mobile Pixel Link (MPL), their system for serializing video data for delivery to a display panel. During a briefing, I was surprised to hear claims of power savings that arise from converting the video data from parallel to serial. It would seem to me that the cost, in power, of the conversion itself would consume more power than could be saved. Not so, they said, and in a follow-up email, a National spokesperson elaborated:
"A parallel interface is lower power with static images, but when running video the parallel interface has to keep all 28 lines powering up and down to pass the data. A well-designed serial interface is much lower power because only a few lines are powered up and down.
To quantify this, a parallel interface showing a static image burns about 10mWatts. This same interface burns between 100-150mWatts showing full motion video. MPL uses only 20-24mWatts for full motion video."