I have an idea that requires switching based on one of three input voltages. The basic idea is to have three different circuit behaviours based on three different voltage inputs. I've been doing this successfully with comparators, but that takes a lot of space. I'd like to do the same thing with discrete transistors or transistor arrays. Does this sound reasonable, or are the comparators actually the right solution?
It seems to me that if I had N and P transistors with one rather low voltage threshold and also had N and P transistors with a higher voltage threshold I could arrange them in various configurations to switch all sorts of ways as long as the voltage thresholds didn't overlap. However, in searching digikey, I couldn't find transistors with differing voltage thresholds clearly delineated. Are they all pretty much the same based on some physical fact of their manufacture or am I just looking for something really unusual?