Operational Amplifiers

An operational amplifier (op-amp) is an electronic component designed for voltage gain amplification. Op-amps most often include a differential input (Vin±), inputs for power supply (Vs±), and a single output (Vout). For an ideal op-amp there are two laws determining its main properties:

  1. 1.The op-amp will attempt to keep the differential inputs the same (Vin+ = Vin-).
  2. 2.No current flows into or out of the differential inputs. For a non-ideal op-amp the low leakage current is due to the high impedance input stage composed by transistor gates.

Using the two laws, a number of configurations for different purposes can be obtained by creating circuits with op-amps and other components, often resistors. The most common configuations are available as built-in modes on SAM L21 as presented in Built-in Modes.

Figure 1. Ideal op-amp