Hi,
I'm developing an application where I have 30 boards each one containing one AMC1301 that I would like to connect to a NI PCIe-6323 card. This is a 32-channel Analog Data Acquisition card. The VOUTP and VOUTN outputs of the AMC's both vary in regard to GND (from VDD2 power supply). So basically my analog reference is floating in regards to GND. If I were to connect the VOUTN outputs of these 30 AMC1301's together and connect them to a floating reference pin (called AI SENSE on that card), would this work?
For those of you not familiar with NI DAQ cards, the analog inputs can be connected as shown in the following picture:
If the VOUTP and VOUTN are really "floating" in regard to GND, than I could connect all of my AMC1301 outputs like shown in the column "Floating Signal Source" and pick either the RSE or NRSE configurations, preferably the latter. See this paper for more info:
But if there not floating, and instead the VOUTP and VOUTN outputs are referenced to VDD2-GND, connecting the VOUTN pins together, as a virtual AI GND, would not work, because the VOUTP outputs will not maintain their voltage differentials in regard to this virtual reference, as it would if the output were a truly floating signal source, like an array of batteries or thermocouples.
Please let me know if my assumption is correct or not.
Will I be able to connect the VOUTN lines of my 30 AMC1301's together, or not?
Thank you in advance for your help.
Habil Silva
CONTROLAR
Portugal
