Por otra parte en el datasheet la info me pareció poca como para poder avanzar,
Temperature sensor
The temperature sensor has to generate a voltage that varies linearly with temperature. The
conversion range is between 1.8 and 3.6 V. The temperature sensor is internally connected
to the ADC1_IN16 input channel which is used to convert the sensor output voltage into a
digital value.
As the offset of the temperature sensor varies from chip to chip due to process variation, the
internal temperature sensor is mainly suitable for applications that detect temperature
changes instead of absolute temperatures. If an accurate temperature reading is needed,
then an external temperature sensor part should be used.