Operational amplifiers are very versatile electronic devices. This is a sampling of the kinds of devices which can be created with a single op-amp.

For an ideal op-amp, the inverting amplifier gain is given simply by

For equal resistors, it has a gain of -1, and is used in digital circuits as an inverting buffer.

For an ideal op-amp, the non-inverting amplifier gain is given by

The behavior of most configurations of op-amps can be determined by applying the "golden rules". For an inverting amplifier, the current rule tries to drive the current to zero at point A. This requires:

This gives the voltage amplification

The behavior of most configurations of op-amps can be determined by applying the "golden rules". For an non-inverting amplifier, the current rule tries to drive the current to zero at point A and the voltage rule makes the voltage at A equal to the input voltage. This leads to

and amplification