Displayport adapter dongles are ubiquitous, now that DisplayPort is becoming more and more prevalent in desktop video cards. I probably have at least a half-dozen of them, connected to machines or stuck in junk drawers. You plug them in, and they work. Simple.
Last week at work, we had a discussion about implementing DisplayPort to DVI conversion in one of our products. I suggested that the conversion might be quite simple – I mean, there exist “passive” DisplayPort to DVI dongles and “active” DisplayPort to DVI dongles. Surely the “active” ones do something to the signal, but “passive” means no active components, right? …right?
Well, it turns out I couldn’t be more wrong. After a reality check by a fellow engineer and a little bit of destructive evaluation, I have now been reeducated in the inner workings of DisplayPort to X conversion.