ratiometric sensor

[blind1]

I have an application using Hall effect current sensor  that generates a ratiometric output voltage proportional to current.

The output of the sensor is input to a NI 9205 in a cRIO. Is it possible for the sensors supply voltage to be derived from the same voltage source as the NI 9205 A-to-D converters reference voltage to eliminate errors due to power supply fluctuations.

Thanks

[GarPar]

Hi blind1-

     What sensor are you using?  What exactly is the concern?  If you are worried about using the same ground reference, you can certainly ground your sensor using a ground terminal on the 9205.  If you are using a bridge-based sensor, you can use a second analog input channel to detect the voltage at the bridge and account for that in your ratiometric output by dividing by the 'actual' voltage.

     I hope this helps.  Best of luck with your application!

[blind1]

I am using Allegro ACS712.  My concern is output error . Trying to measure current within 0.5% accuracy.
That looks like one option to use a second analog input to measure Vref at the sensor.
The other option is to Calibrate my system using the scaling factors in software and HOPE Vref doesn't drift.

Thanks