Reason for applying input only to inverting terminal in differentiator and integrator

[vetriece86@gmail.com]

What is the reason for applying input only to inverting terminal in differentiator and integrator in op-amp ?

What happens if we apply input to non-inverting terminal of differentiator and integrator in op-amp ?

can any one describe this in detail using opamp with appropriate figures.


Thank you

 

[Audioguru]

A differentiator and integrator use inverting opamps and are described very well in Google.

 

[LvW]

If you apply the input signal to the non-inv. input terminal the closed-loop gain is Acl=1+Zf/Zin.
Hence, you have Acl=1+integrator/Diff. function.
This will result in a proportional-integrator function (PI) or a prop.-diff. function (PD).

 

[ahsan_i_h]

What happens if we apply input to non-inverting terminal of differentiator and integrator in op-amp ?

If you apply input to non-inverting terminal of integrator or differentiator, you will get non-inverting result at output but with input signal added. See the schematic with equations below.



These are not true integrator or differentiator but applicable in control engineering for PI or PD feedback. A true integrator or differentiator should have only the integral or differential result at output, which can be achieved by applying input to inverting terminal.