Operatiivisvahvistin

Operatiivisvahvistin, often abbreviated as opamp, is a fundamental building block in analog electronic circuits. It is a high-gain, direct-coupled, differential voltage amplifier with a single-ended output. The name "operational" stems from its early use in analog computers to perform mathematical operations like addition, subtraction, integration, and differentiation.

An ideal opamp has infinite open-loop gain, infinite input impedance, and zero output impedance. In practice, real opamps have very high, but finite, open-loop gain and input impedance, and very low, but non-zero, output impedance. These characteristics allow opamps to be used in various circuit configurations, such as amplifiers, filters, oscillators, and comparators, by employing negative feedback.

The opamp has two input terminals: a non-inverting input (marked with a plus sign) and an inverting input (marked with a minus sign). The output voltage is proportional to the difference between the voltages at these two inputs, multiplied by the opamp's open-loop gain. When negative feedback is applied, the opamp attempts to drive the voltage difference between its input terminals to zero, a principle that simplifies the analysis of many opamp circuits.

The versatility and relative simplicity of opamp circuits have made them indispensable in countless electronic devices, from audio equipment and medical instruments to industrial control systems and communication technologies.