It decreases the AC gain at high frequencies.That makes sense, thank you. So R2 + R1 and C create a high pass filter. Now, I have also seen a small cap, say 22pF, in parallel with the R2 resistor. What does that cap do?
Usually that capacitor is to allow offsetting the input DC voltage (typically by 1/2 the supply voltage) to allow an op amp that normally requires dual supply voltages to operate from a single supply. It makes the DC gain equal to +1 but the AC gain is determined by the ratio of the two resistors.Newb question. On the non inverting amp below, what is the capacitor for? I see the capacitor on some circuits but not on others. Does it make a difference if the circuit is single supply or dual supply?
Thanks.
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