My application has a temperature range of 0°C to 45°C. Is it possible for me to calculate (or approximate) the ADR421 output voltage hysteresis for this temperature range ?
First of all, may I know your application to help you better.
For the meantime, I don't know if you already saw the computation of Thermal Hysteresis on page 16 of the data sheet. It is the change in output voltage when the device is cycled through temperature from +25 to -40 to +125 then back again to +25 all in degree C and what is given in the datasheet's electrical specifications is the typical value for this device. In your case, I will still look on how to at least approximate that parameter in your temperature range.
The product owner of ADR421 said that output voltage hysteresis is test to specific temperature range and we don't have data on your temperature range. However, I can say that the one stated on the datasheet can be the worst case value, it was cycled to the full temperature range of the device but it is just typical value, it can go above and below it.