I am just coming from anothr controller and learning the different parts of the STM32L0 for low power applications. I am about to start on the 12bit A/D, which hopefully will save me having to add an external one. As the VREF is internal to the processor, how accurate has anyone found this? The 12 bit is good, but I need an accurate reference voltage. Can anyone let me know how accurate you have found it to be?