Instruumendivõimendeid

Instruumendivõimendeid, often translated as instrumentation amplifiers, are specialized electronic amplifiers designed for high precision and accuracy in measuring and amplifying small differential signals. They are commonly used in applications where signals are weak, susceptible to noise, or require a high degree of common-mode rejection. A key characteristic of instrumentation amplifiers is their ability to amplify the difference between two input voltages while suppressing any voltage common to both inputs.

These amplifiers typically consist of three operational amplifiers. Two of these are configured as non-inverting amplifiers, each with one input connected to one of the differential signal terminals. The third operational amplifier is configured as a subtractor, taking the outputs of the first two amplifiers and producing the final amplified differential signal. This architecture provides a very high input impedance, which is crucial for not loading the signal source, and a very high common-mode rejection ratio (CMRR), meaning they are very effective at eliminating unwanted noise signals that appear on both input lines simultaneously.

The gain of an instrumentation amplifier is usually set by a single external resistor, making it easy to adjust and calibrate. This feature, combined with their precise amplification and noise suppression capabilities, makes them indispensable in fields such as medical instrumentation (e.g., ECG, EEG), industrial control systems, sensor interfacing, and audio signal processing where faithful reproduction of small signals is paramount.