One additional question. Based on my numbers, -80 dB from a 500 mV input signal works out to 50uV. For the gain resistor I'm using (750 ohm), this works out to a gain value of 66. Does this gain value still need to be applied against the 50uV for an expected result of 3.3mV? I'm not clear on whether the gain value is applicable to the common mode signal or whether I can safely assume that this gain number applies ONLY to differential signals.
Just want to clarify if I'm understanding the expected result properly.