ABSTRACT
An operational amplifier (op amp) is an electronic device or integrated circuit made of transistors and resistors used to amplify or attenuate inputs. The op amp can be used for mathematical operations such as addition, subtraction, multiplication, division, differentiation, integration, and filtering. The most common analysis technique for an ideal op amp circuit is Kirchhoff’s current law (KCL). By using KCL and the two ideal op amp assumptions, it is possible to find the output voltage and current for any op amp circuit. The differential amplifier has a differential input mode defined as the difference between the two input voltages. The second feature of a difference amplifier is the common mode input, the average of the two input voltages. Ideally, the common mode gain should be zero and only the differential input should be amplified. One of the most fundamental considerations when designing an op amp circuit is the selection of the input, feedback, and load resistors.
