operational amplifier - How to identify the feedback topologies?

It is extremely important to identify the feedback topology first before starting analysis. However, I find it difficult and cannot get it right.

Is there an accurate yet easy way for me to identify one out of the following four feedback topologies?

1. Series-series


2. Series-shunt


3. Shunt-series



4. Shunt-shunt

Answer

The problem is that from a term "Series-Shunt" it is not clear what comes first: "in" or "out"? I have discovered that different authors handle this subject differently. For this reason I prefer, for example: Voltage-controlled current feedback.

Examples:

• Voltage-controlled voltage feedback: Non-inverting opamp,


• Voltage-controlled current feedback: Inverting opamp,


• Current controlled voltage feedback: Common emitter stage with Re feedback,


• Current- controlled current feedback: (a) Inverting OTA amplifier, (b) common emitter stage with a voltage divider between collector and signal input (base node at the middle point).