Choosing the correct amplifier

摘要

Perational amplifiers are fundamental because they can perform any amplifier function. The op-amp name stems from the days when analog computers reigned supreme and feedback amplifiers performed mathematical functions. Feedback makes an amplifier's performance a function of the passive components, resistors, and capacitors, rather than of the active devices. Four impedances make up the basic op-amp circuit (Figure 1, Reference 1); you use resistors for gain calculations, but when you replace Z_1 with a capacitor, the circuit becomes a differentiator. When you replace Z_2 with a capacitor, the circuit becomes an integrator.