Can I tune this LPF on chip?

[yolande_yj]

I need to design a high order LPF on chip. I choose a MFB 4th order Chebyshev LPF as shown below. But how to tune it? Without tuning, I think the filter can hardly work in IC design.

 

[rfsystem]

Split the cap into slices and switch them. Switching caps is better because the MOS resistance impact only the high frequencies. Sometimes it could compensate the parasitic pole of the opamp with the RMOS*C.

 

[yolande_yj]

the MOS resistance impact only the high frequencies.

What MOS resistance? Thanks.
Let's say for every Cap I layout 4 slices with ratio of 1:2:4:8, inorder to choose one of them I need 2 bit (2^2=4), then for the whole filter, 4 Caps need 8 input pins. And I also need to implement small decode logic for every Cap. Is it efficient to do that? Is there any pratical way?

 

[rfsystem]

Yes, MOS switch on resistance!

For IC implementation switching cap is standard. The MOS devices size is proportional to the cap size. The factor depend on the parasitic zero introduced.