Dear Mariusz,
Following your experience, AC coupling is better for AFE5801. Right?
I want to use AFE5801 to build a 32-Channel daughter board for positron emission tomography (PET), eight daughter boards will connect to a mother board. I think a digital control is better. If I use analog TDC and there are some difference of the output of the DAC, I think the gain will be alight difference.
In the AFE datasheet, it says:
In the case of ac coupling, the external input capacitors form a high-pass filter with the internal bias resistors (5kΩ), so, the value of the capacitors should allow the lowest frequency of interest to pass with minimum attenuation. For the typical frequencies used in ultrasound (>1MHz) a value of 10nF or bigger is recommended.
If I use AFE5801 for PET signal, I think I need a frequency from very low frequency to some high frequency. I think I need to use a capacitor with big value. Right?
Thanks.