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We have 4 negative feedback topologies;series-shunt, series-series, shunt-shunt, shunt-series. I'd like to know something where we use these topologies. What are advantages compared to their each other ?

Piko
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    Take an operational amplifier and analyze by yourself if some feedback alternatives exist. – LvW Jan 17 '21 at 09:36
  • But this would be special case. I want to learn more general things. – Piko Jan 17 '21 at 15:32
  • However, based on opamp circuits, you can at least study two diifferent (out of four) feedback topologies and their influnence on input-/output impedances. – LvW Jan 17 '21 at 17:37

1 Answers1

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Based on the requirements of the application, the different topologies of feedback amplifiers are used accordingly.

Operational Amplifier: an ideal one has an infinite input impedance (to avoid loading effect) and very low output impedance. A series shunt (or voltage series) feedback amplifier topology has a high input impedance and a low output impedance. A voltage shunt (shunt shunt) feedback amplifier topology has both low input and output impedances. A series series (current series) feedback amplifier topology offers a high input impedance as well as a high output impedance.

Kaswechiha
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    "...series shunt (or voltage series)"...Although I agree with you, I do not like at all such a (to me: confusing) terminology. In this case I prefer: Voltage-controlled voltage feedback. – LvW Jan 17 '21 at 10:24
  • Yes what you said is right but not enough I guess. Why we need to these topologies ? Why we need to low input impedance ? Where we use them ? – Piko Jan 17 '21 at 15:31
  • https://electronics.stackexchange.com/questions/68638/why-is-it-desirable-in-an-amplifier-to-have-high-input-impedance-and-low-output https://electronics.stackexchange.com/questions/21787/why-is-high-input-impedance-good Do these answer your part for explanation of high input impedance and low output impedance requirements? – Kaswechiha Jan 18 '21 at 04:27