OP-Amp and Capacitors

[coolrox86]

Hello,

Recently I have a homework about op-amp and capacitors. I have to calculate the output voltage Ua (see attached picture). Does anyone know how to calculate it?

Any help and suggestion is kindly appreciated. Thanks in advance!:smile:

*by the way happy new year 2012!!!

Regards,
coolrox

 

[DartPlayer170]

I'm not really sure, but it looks like Ua = -(U1+U2) * Acl
where Acl will be determined by Xcv / ( Xc1 || Xc2 )
from a practical point of view I don't think the circuit will actually work because there is no dc path for the -ve input.

 

[chuckey]

The inverting input is a current summing point, so all the current sum to zero, i.e. the two input currents equal the output current.
Frank

 

[LvW]

To answer the question it is absolutely necessary to know if the opamp has to be assumed as ideal or as a real device.
In the latter case, the circuit will not function at all as an amplifier.
In the first case, it is a theoretical exercise only - nothing else, since there are no ideal devives in reality.