ADS4129: How to calculate the filter's capacitance of the ADS4129's input

Hello！

In the input frequency is 250 MHZ, the input capacitance is about 3.6 PF, the input resistance is about 500 Ω，Can you tell me the relationship between the capacitance of r-c-r and the maximum input frequency？

Thanks

User,

The r-c-r is a 250MHz low pass filter. If your IF is going to be above this frequency, remove these parts from the EVM.

Regards,

Jim

Hello，

I want to  set the frequency 50MHz ,How should I calculate?

Thanks!

Use a filter simulation tool and enter the values for the internal R and C from Figures 114 and 115 at 50MHz. This would be about 10KHz and 4pF.