How to find Topologies of an amplifier?
For describing a certain feedback topology, I do not like terms like shunt-shunt or series-shunt etc.... because it is not clear if it is related to the sequence output-input or input-output (both are in use).
Therefore, the feedback signal is derived from the output voltage (it is part of Vout) and we have &quot;voltage controlled feedback&quot;.
However, when Vi is an IDEAL voltage source, the feedback signal is shortened and has no effect. Hence, I assume that Vi has some internal resistance. In this case, two currents are combined at the source node: The current through R3 and the current driven by Vi (similarly to an inverting opamp-based amplifier stage).
As a result, we have &quot;voltage-controlled current-feedback&quot;.