Mark Rages wrote: > > I thought the whole point > of a Schmitt input was to give the input a little "snap" and therefore > increase the rise/fall times. It will.
In my setup, 2 channels each setup as I described. The relative phase from one channel to the other remained pretty much constant throughout the various stages (which I require), including the slow-edge opamp circuit. It all fell apart going through the schmitt trigger. The faster edge into the schmitt trigger eliminated the phase/timing distortion. All in all, and I think most people agree, this isn't the ideal circuit for the given application :) I don't even want to describe the lousy asynchronous flip-flop design that follows the schmitt trigger for fear of a scolding :) (not my design, I have to repeat that for my sanity) In fact, I've done something similar to > what you're doing. IIRC, it was like this: digital signal -> big long > RC -> schmitt inverter -> 4000-series flip-flop clock. And that > circuit, inelegant as it was, worked fine. yep. You need the fast-ish edge for the clock. The CD4000 logic don't require very fast edges (5uS rise, for example) to work. Anything slower and you cannot guarantee the timing specs. That's what the scmitt trigger did in your case. _______________________________________________ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user