I am currently using the AD7734 evaluation board for some testing. I am feeding a sine wave through a first order low pass filter and feeding both the input and output of the filter through the A/D and measuring phase delay. I designed my filter to have minimal phase delay (~170 us) at 1.6 Hz (my frequency of interest). I am looking for a ~0.1 degree phase shift. I have designed filters that more than meet this spec, but when I feed them through the A/D I see a delay of 2-3 ms. Is there a set delay between the channels of the A/D? I assume there is as I don't think this A/D is truly simultaneous.