AnsweredAssumed Answered

AD7708 strange behaviour at cold temperatures

Question asked by tneagoe on Sep 4, 2015
Latest reply on Nov 2, 2015 by Ren

 

Hello there,

With the AD7708, we are experiencing a strange behavior with sudden changes of temperature.

If there is a rapid cooling of the device down to -40 Celsius, it happens that a reading is completely erroneous.

This behavior happened when verifying the robustness of our product in thermal shock.

We have been able to reproduce the problem with a can of spray freeze.

 

I have read this in the datasheet for the calibration: 

 

 

 

“It should also be noted that to optimize@@@

calibration accuracy, all AD7708/AD7718 ADC calibrations

are carried out automatically at the slowest update rate with

chop enabled.”

 

Does it mean that the SF must be set to 255 to avoid this error ? 

Please advise,

Teodor

 

Outcomes