The EFM32 has a built-in temperature sensor and can measure temperature using the built-in ADC.
However, their applications are limited compared to thermistors, mainly for the following reasons.

• The object to be measured is the temperature of the EFM32
• Temperature sensor accuracy (Min/Max) is not specified

Typical uses include activating a cooling fan when the temperature is high, and reducing the processing load on the system when the temperature is high (such as slowing down the operating speed of the system). Application note AN0006 (Tickless Calendar with Temperature Compensation) also uses it for dynamically correcting RTC temperature deviations.

For typical part characteristics, datasheets provide temperature vs. ADC value curves. The figure below is an excerpt from the EFM32GG990 datasheet.

Each device has different offset errors and slope errors. calibration at one temperature) can suppress the slope error to some extent.

Please also check the Silicon Labs community site.