differential vs nrse on ground referenced signals

[Gordal]

Is there any difference in terms of noise rejection when using a differential input adc on an analog input, where one input is ground, vs nrse where we are referencing the ground on one pin? Im using a usb-6218

Message Edited by Gordal on 05-26-2010 09:25 AM

[Norbert_B · Accepted solution]

The advantage of differential is that each input channel has its own "reference" and only the difference between the actual channel (AIx) and this reference (AIx+8) is measured. This method has the highest chance for proper noise reduction since there are (hopefully, depending on your wiring) no interference to other channels. The disadvantage: you cut the amount of avialable channels to half.

NRSE "shortcuts" all channel "references". So if one channel introduces noise on this reference, all channels are effected by this.

Another point might be that this "shortcut" could be a problem for the circuit you want to test/measure......

hope this helps,

Norbert

[EDIT] Please post this question in the DAQ forums in the future since it has nothing to do with LV

Message Edited by Norbert B on 05-26-2010 09:41 AM