Hi there,
Before I ask my actual question: I'm not an EE. Please forgive me for probably butchering EE technical terms. I'm trying my very best to avoid it.
So I've build this comparator circuit with a feedback resistor for hysteresis:
I do understand, that an real world opamp (or comparator) does have a non-zero input offset voltage. So the voltage that's required on the input to make the output change state might be different between two different comparator types, two different comparators of the same type or even vary with environmental influences such as temperature. (Also, I'm writing 'change state' which is probably incorrect, since the output doesn't have two discrete states but just amplifies the voltage differential and I do realize that a real-world opamp does not have infinite gain, but 'change state' is the best explanation I can give).
The question is: If there's an output transition at a given time t0 and another ouput transition later at t1, how different could the input voltages at t0 compared to t1 have been (assumed that the environmental conditions such as temperature, reference voltage, actual resistance of the individual resistors etc. are the same). I think that is what an EE calls stability. Is a comparator (or opamp) in this case significantly different from a schmitt trigger (real-world jellybean devices, such as the 74hc14 or so).
I'm asking because an EE confused the hell out of me by saying an opamp would always be infinitely better than a schmitt trigger is this situation. Keep in mind, that I'm not interested in the actual input voltage that makes the output change state, as long as it's the same input voltage at t0 and t1, so as far as I understand, input offset voltage should not be an issue as long at it is a constant. Also, when I ask EEs they usually ask me about SNR and input frequencies, so let's assume no noise and a frequency of maybe 1 Hz.
I'm not trying to start a super theoretical discussion about opamps, but usually when I ask EEs these type of questions they just hit me back with a ton of technical terms and I'm trying my best to ask a question that's as unambiguous as possible.
Thank you for taking the time to read my question. Any pointers (also to what I have to look for in a datasheet) are greatly appreciated.
Cheers!