Other Parts Discussed in Thread: ADS122U04
I am very confused regarding the selection of the anti-aliasing filter cut-off frequency. I see there are 100 Ohm series resistors and 4.7 nF CM capacitors. That creates a CM filter with cut-off frequency of 338.6 kHz. In my opinion, that is way too high. The modulation frequency of the ADC is 256 kHz at normal mode. Even if we assume the ADC works at its maximum sampling rate of 2 KSPS, the 338.6 kHz is much higher than what is recommended in the datasheet. There it is mentioned that the anti-aliasing filter should be set at around the sampling rate or 10 times higher.