# How is this series series feedback topology forOPAMP?

This is stated as series series type of negative feedback but why.

Whereas this one is series shunt topology

• The 1st has the output load in series with R to provide current limit but does not share ground return like the shunt output.. The 1st is a also voltage to current converter dependant on load R Mar 1, 2019 at 1:57
• If i guess what you mean to say is if current through load resistance is considered zero then feedback voltage is observed ,is it that you meant. Mar 1, 2019 at 2:12
• No the OA input current is always assumed zero with 0Vdiff, so the current flows only thru the resistor paths from source and output Mar 1, 2019 at 2:18
• Yes input current has to be zero but load current can occur due to output voltage.Is the current through load what you considered / made zero to find the type of sampling in the above circuits. Mar 1, 2019 at 2:21
• yes the 1st uses series current source Vin/R thru RL to achieve gain 1+ RL/R while second uses shunt voltage source with same gain 1+R2/R1 independent of RL Mar 1, 2019 at 2:28