01:16 Today's focus is on understanding voltage-voltage feedback. 04:16 Understanding Four Feedback Topologies 10:08 Different feedback topologies for impedance amplifiers 13:11 Different feedback topologies have different features and affect the output impedance. 19:11 Using feedback to adjust the overall voltage gain. 22:06 Key points about input and output impedances in voltage-voltage feedback topology 27:08 Analysis of feedback topologies with voltage and current 30:17 Negative feedback increases input impedance in voltage-voltage amplifiers. 35:09 Finding closed-loop output impedance 37:58 Feedback reduces output resistance by a factor of (1 + Ka) 43:22 Voltage-Voltage (Shunt-Series) Feedback Topology discussed. 45:57 Voltage-Voltage Feedback Topology Characteristics Crafted by Merlin AI.
You have your topology naming backwards. What you labeled as shunt-series is really series-shunt. You explained it correctly, but the common naming convention is input-output. Input is in series and output is shunted, so the name should be series-shunt as opposed to how you labeled it, shunt-series.
but for the sense&return network (feedback network), the sense is input and the return is output. The sense is at the output of the entire system and the return is at the input. So if you think this way, the naming is actually correct.
Naming conventions are not a problem so long as you understand how they are being named. Are you going to call out on someone because they said sigma-delta modulation as opposed to delta-sigma??
These are extremely useful lectures for which I am very grateful. I have some doubt though: When the Prof speaks in many locations including here at about 18:26 explaining how Vin and the Return voltage U are connected in series to build the difference Vin-U. Here he mentioned repeatedly that Vin, U and the input of A1 are all connected in series. Here is where I have doubt: I agree that Vin and U are connected in series and at the resulting two terminals of this connection we have Vin-U. This difference is in my opinion connected in parallel to A1 input as A1 is supposed to sense (measure) this difference exactly the same way a Voltmeter would be connected to measure (sense) the difference. Am I mixing something here?
28:30 - Input impedance is being bootstrapped (Miller Effect) and thus lowered by the negative feedback. For inverting amplifier configuration, the configuration would be called Voltage-Current/Shunt-Shunt?
