The EIA standard (EIA-198) stipulates the following.
< Temperature characteristic specification >
Considering the capacitance change ratio as stipulated in the EIA standard, we can say that the capacitance change ratio within the operating temperature range becomes larger in the following order: X7R < X7S < X7T.
On the other hand, when we compare the effective capacitance under actual usage conditions, the capacitance change ratio trend may differ in some cases from the EIA standard.
Comparing the temperature characteristics under 0 Vdc conditions, the capacitance change ratio of the X7R is lower than that of the X7T, meaning the X7R exhibits less capacitance change.
On the other hand, when we compare them under actual usage conditions, both the X7R and X7T have a large capacitance change ratio at the low-temperature end of the operating temperature range, which extends in its entirety from -55 to 125°C.
In addition, a comparison at -55°C when the capacitance change ratio of both the X7R and the X7T is at its largest shows that the effective capacitance of the X7T is greater than that of the X7R.
The above is just one example, and the trend for each part number will be different. When selecting components, make sure use the SimSurfing design support software to confirm your choices.