OP- amp need to be solved - output?

[mjazairli]

Hello I need to see the output of this op-amp structure.
thank you

 

[CataM]

In red is the asymptotic approximation. In blue, the real graph.

 

[mjazairli]

Thank you for the answer, can you please explain a little more the result?

 

[CataM]

Vout(s)/Vin(s)=1+RCs assuming no initial conditions. The transfer function is a simple "real zero" which is represented in Bode plot like I drawed. When ω=1/RC the amplitude is sqrt(2) and in dB is 3 dB.
When ω<<1/RC amplitude is ≈1 meaning 0 dB.
When ω>>1/RC amplitude rises with +20 dB/dec.

If ask me more specific question, I know where to focus...

 

[mjazairli]

every thing before w=1/RC is clear to me, but how did you draw the line at 90 degree?

 

[CataM]

First of all, on post #4, where you see amplitude replace that word by gain. Calling it amplitud is wrong.

how did you draw the line at 90 degree?

G(s)=1+RCs => G(jω)=1+RC·jω this has module and phase.

Phase(ω)=arctan(RC·ω). When ω=1/RC => phase=45º. It is just a mathematical plot.
When ω=0.1 · 1/RC => phase ≈5.7º
When ω=10 · 1/RC => phase ≈84.3º