ABSTRACT
Operational amplifiers are analogue integrated circuits designed for linear amplification that offer near-ideal characteristics. It can be thought of as universal gain blocks to which external components are added in order to define their function within a circuit. Open-loop voltage gain is the output and input voltages and the closed-loop voltage gain of an operational amplifier is the ratio of output voltage to input voltage. Input resistance is the ratio of input voltage to input current; the output resistance is the ratio of open-circuit output voltage to short-circuit output current. The slew rate of an operational amplifier is the rate of change of output voltage with time in response to a perfect step-function input. A differentiator produces an output voltage that is equivalent to the rate of change of its input. A summing amplifier produces an output that is the sum of its two input voltages.
