I'm interested in using the STM32F4xx internal sensor in a deployed product. Any comments on temperature sensor accuracy and calibration are welcome and appreciated.

[rgodshall]

Per STM32F405/7 and per datasheet DocID022152 Rev 8 (stm32f4xx) ... are the values referred to in datasheet as "Temperature sensor calibration values", at addresses 0x1FFF 7A2C & 0x1FFF 7A2E (see section 5.3.22), actual factory-calibration results that are populated for each part? Is there any further documentation that I can refer to for more information on this? Section 2.2.36 states that the sensors are not suitable for accurate readings, which seems to contradict section 5.3.22 if indeed I've interpreted it correctly. I'm interested in using the internal sensor in a deployed product. Any comments on temperature sensor accuracy and calibration are welcome and appreciated. 

[Uwe Bonnes]

Pay attention that the sensor measures the chip temperature, not ambient temperature! The F405 is no low power chip and when active and even sleeping, chip temperature will be substantial higher than ambient. Otherwise when measuring often and calculating mean, measured values are stable and reproducible in my experience.

[S.Ma]

Agreed, what is measured is the junction temperature (heat generated by silicon) that has to be dissipated through the package which acts as heat sink (theta Tj)

The 2 values are measured at 2 different junction temperature. Take the ADC value and linearly interpolate. ADC pre-calibrated.

You can also monitor the Vdd line of the MCU internally and sometime the VBat.