Electronic – name for this kind of comparator

comparatoroperational-amplifier

I have two analog signals, and I need to generate digital signal (to use as an interrupt for an MCU) when the voltages differ more than a certain amount. It's going to be some sort of comparator arrangement, but does this have a name? Window comparators are in the right kind of area, but aren't differential.

Best Answer

does this have a name?

Yes, it is a window comparator even though you think it isn't. Regular window comparators have one "variable" input but there's nothing wrong with the "fixed" input being variable too. Consider this "regular" circuit: -

enter image description here

If the middle of the three resistors were, in fact, two resistors in series (with the new input feeding the centre-point) then you get a window (magnitude) comparator. Depending on precisely how you want this to work you can make the two outer resistors into a current source and a current sink and you could even use something like a TL431 across the full width of the middle resistor to define precise thresholds above and below the new reference input.

It's still a window comparator.