Good day! I am posting this on behalf of the customer.
I use ADS1220 as ADC to assemble pressure and temperature sensor. For cost saving, I use an internal temperature sensor as a temperature source and use a MEMS bridge to generate pressure signals.
After calibrated pressure, The accuracy is OK. But the temperature signal has a bigger error based on the datasheet specification 0.5℃. When the ambient temperature is above 10℃, the accuracy is good. Below 0℃, for example, -20℃, the error is about 3℃. It seems I need to calibrate the internal temperature sensor. Do you think the internal temperature signal is abnormal?
I want to have some test data so I can estimate multi-order fitting. Can you provide me? Or do you think linear fitting? third order fitting or even more? Even Segmental fitting?
Thank you in advance for your support.