I have a problem with the ADS124S08 device.
I use the device to detect the temperature with a PT100.
I use the 4-wire configuration with low side Rref as shown in the figure ([NM] = not mounted).
Below I report the configuration
IDAC1 = 2mA, IDAC2 off
Sinc filter selected
SPS = 2.5
AIN3 = positive input channel, AIN4 = negative input channel
Everything works fine. Sampling for 10 minutes I have a maximum variation of 0.002 ° C on the acquired samples.
But on a batch of 10 devices 2 have a variation of 0.15 ° C.
To solve the problem just change the ADS124S08 and the system returns to work correctly with a maximum variation of 0.002 ° C.
Why does this happen? is it an electrostatic discharge problem?
Changing the ADC is very expensive.
Can anyone help me out?
Thanks so much.