A Design Idea of mine that appeared in EDN around 2000. The article appeared with the title ‘Lost Cost . . . ‘ – seems someone got a bit mixed up. The idea has been referenced in a few papers on the web – always good to see!
Here’s another one using a delta modulator that also works very well. I submitted this to EDN but it was rebuffed. I guess whoever reviewed the idea wasn’t used to seeing an opto operated in photo-diode mode.