In the preceding paragraphs we have discussed the effects of
op-amp limitations, taking the example of the simple inverting
voltage amplifier circuit. Thus, for example, op-amp input
current caused a voltage error at the output. In a
different op-amp application you may get a different effect; for
example, in an op-amp integrator circuit, finite input current
produces an output ramp (rather than a constant) with zero
applied input. As you become familiar with op-amp circuits you
will be able to predict the effects of op-amp limitations in a
given circuit and therefore choose which op-amp to use in a given
application. In general, there is no "best" op-amp (even when
price is no object): For example, op-amps with the very lowest
input currents (MOSFET types) generally have larger voltage
offsets and greater noise, and vice versa. Good circuit
designers choose their components with the right trade-offs to
optimize performance, without going overboard on unnecessary
"gold-plated" parts.