You need a TVS diode because many voltage regulators do not have the ability to sink current, nor can they respond fast ...

If those part numbers don’t mean anything to you ... If you apply a square wave to the input of an op amp, then the output will rise and fall at the op amp’s slew rate. The slew rate is ...

The ideal op amp — which we can’t get — has infinite gain and infinite input impedance ... the slew rate and you’ll usually find this number on the device datasheet.