Make It Simple

Recently I have been studying the opamp circuits and their application.  One of those circuits is a differential amplifier circuit. I wanted to make the article for the derivation of the differential amplifier circuit. Lets dive into the topic. Differential amplifier is nothing but the combination of the inverting and non-inverting amplifier circuit. The output equation of inverting amplifier is given by `Vo1=-\frac{R2}{R1}\times V1`   --- (1) The output equation of the non-inverting amplifier is given by `Vo2=(1+\frac{R2}{R1})\times V2` ---(2) Applying superposition theorem, the output of combining inverting and non-inverting amplifier is given by `Vo=Vo1+Vo2` ---(3) `Vo=-\frac{R2}{R1}\times V1 +(1+\frac{R2}{R1})\times V2` ---(4) The equation of the differential amplifier is given by `Vo=K (V2-V1)` ---(5) From the equation (4), the amplication factor K can be derived if `-\frac{R2}{R1}=(1+\frac{R2}{R1})` It can be done by adding the voltage divider circuit at the input o...