Hi all. I've been looking at Sigma Delta ADCs lately and comparing them to SARs ADCs and it never occurred to me that sampling rate might be different than bandwidth. I used to think that the bandwidth of an ADC is half the sampling frequency, but apparently not? There are 200ksps ADCs out there with bandwidths of 4MHz, so I am not quite sure what this means, unless it is referring to the instananeous frequency components measured in a single sample (which doesn't seem to make sense).
I am also a bit confused about the the input bandwidth of a sigma delta ADC. The maximum bandwidth that you *should* input to a sigma delta ADC is half the output data rate, right? Not of the sample rate which is much much higher and includes oversampling?