Operational amplifier

Circuit diagram of an operational amplifier

The operational amplifier (OA) originated in computer technology but has now become established in a wide variety of applications. Examples include DC and AC voltage amplifiers, amplifiers in control circuits and threshold switches.

Fundamentally, an OA comprises an inverting and a non-inverting input (I1, I2), an output (O) and a supply voltage ${V_b}$. When not connected to other circuits, the OA has a very high amplification factor of between 10⁴ and 10⁶. When connected to other circuits, it is relatively easy to implement many different applications. Typical OA applications include Impedance converters, summing amplifiers, level converters, integrators and differentiators.