Temperature Drift is the change in reference voltage over temperature. This specification is usually defined by the box method technique. More details on how the box method is calculated are in TI’s Voltage reference selection basics white paper. There are several considerations when choosing the correct temperature drift due to the non-linear nature. One consideration is that the drift is usually defined as an average and can be bigger or smaller in particular regions. The shape of the temperature drift curve varies in a linear or non-linear way based on the reference architecture and the curvature correction methods used. One common misconception is that the voltage reference core, buried zener or bandgap, dictates the final temperature drift curvature of the device. This is not the case because most voltage reference cores have surrounding circuitry for trimming and adjusting the temperature curvature which adjusts the original core temperature shape. Table 3-2 shows the relationship between temperature drift and percent error to demonstrate how temperature drift can be compared to accuracy.