Other Parts Discussed in Thread: ADS1235, ADS1261
I am currently using the ADS124S08 in a strain gauge design.
I am running at 800SPS and using a Gain of 64 and a reference of 1.25V
I am running a strain gauge that is a 350 ohm wheatstone bridge at EXC voltage of 5V.
I get poor response to impulse data. it takes several seconds to decay back to a baseline.
I tried running a frequency generator square wave of +3V to -3V with a GAIN of 1 and a Reference of 5V.
I am not able to get a waveform definition for any thing over 1/5th Hz. anything above that and the squarewave looks like a triangle wave at reduced amplitude.
I have tried using the Sync filter and the low latency filter with little or no change. I have moved the SPS around and no improvement either. I have taken all averaging out of my software and cannot get a frequency response over the 1/5th Hz.
Is this a charge dissipation problem? not sure what I am missing here it seems like this chip should be easily capable of tracking a 10Hz signal.
Should there be resistors to ground to bleed the voltage off? I tried a single 1K across the differential with no improvement.