I have a function generator SFG-2110 from GW Instek. I set it to generate a square wave with max/min of aroudn +- 1 V. And I checked with an oscilloscope.
However, when I connected outputs of the function generator to an op-amp comparator with TL972IP from Texas Instrument, voltage significantly drops, even though I DID NOT make any change on the function generator.
I think there's something wrong with circuit impedance. But I've only heard about that and have no idea how to adjust impedance of a circuit.
Why does an oscilloscope show a different voltage from a signal generator? says some generators have High Z mode. But, I can't find such a thing on my one.
Currently, my circuit looks like:
Will this problem be solved if I put a tiny resistor between (+) and (-) of the function generator?
If I am thinking wrong that impedance is a source of the problem, please point it out.