Layout of complicated fully differential feedback network

[Junus2012]

Hello,

For the circuit shown below

you kindly see the complicated network of the fully differential filter,

If I have to interdigitize the elements from top to the counterpart elements in the bottom, it will be really hard. For example if I have to interdigitize R4C from top to the R4C in bottom.

In one of my formal posts, some of the friends suggested that there is no need to di so, but I only need to make the networks of top and down as mirror looking,

but this how could satisfy the matching requirement?

thank you

 

[Dominik Przyborowski]

but this how could satisfy the matching requirement?

One rabbi says "yes", another says "no".

What is more important:
1. Minimization routing cap?
2. Symetry of positive and negative path?
3. RC ratio between stages?
4. Anything else?

Did you check sensitivity of your filter parameters on element variation?
Have you extra spec for group delay or phase?
Any process calibration?

Might happen that the best for you is to keep horizontal symetry and lay down everything like on the schematic.