# Getting wrong results when using switched-capacitor filter. (PSpice simulation)

Okay the idea is to use the following band-pass active filter:

To this filter I want to add a switched-capacitor filter to replace the resistors with capacitors and switches. I'm using the formulas $f_{c1}=\frac{1}{2\pi R_1C_1}$ and $f_{c2}=\frac{1}{2\pi R_2C_2}$ with $f_{c1}=2kHz$. Using those formulas with $R1=R2=2k$ we get $C_1=39.78n$ and $C_2=19.89n$. Finally, we just need to replace the resistors. For that I want to use a clock with $T_s=1MHz$ and to calculate the needed capacitors I'm using $C=\frac{1}{T_sR}$. Then, the capacitors have the same value (because of the same resistors) and are qual to 0.5nF. The schematic is:

All seems fine. However I find the following problems:

1. The bandwidth isn't the desired (it should be 2k, but I get about 4k).
2. The working of the circuits seems independant of the clock pulse. I tried changing it from 1Ghz to 1Hz and the response in frequency is the same. That is strange because clearly something should change if I change the clock.

So, what is going on here? What could be wrong? Am I ignoring something?