Tutorial on how to perform a nodal analysis of circuits containing operational amplifiers (op-amps). Two examples of cascaded op-amp networks are worked through.
man i can not thank you enough i haven't found any video that explains nodal analysis in op amp circuits... and these are the type of videos you need for exams.
Because we're writing the nodal equation FOR Va (when we write a nodal equation for a node we imagine all currents are leaving the node). So what you wrote in your comment is Vs nodal equation, but remember, we don't write nodal equations for voltage sources.
Hello, i think it would be better to draw the Current flow Into or out of a node. The sum of the node currents shall be Zero. If you have drawn the current arrow ist is more obvious how to write the nodal equations.
Setting the constraints (0v between inverting and non-inverting Input, input current=0) hide the impact of input offset voltage and Input bias current. In a Majority of Applications this can be done. On the other Hand for worst case analysis we should Not simply hide these parasitics. For sure the equation will be more complex but with the help of Math tools you can handle this. E.g. Mathcad has implemented Symbolic solver. You only need to enter the KCL and the nodal equations.
