Please note this issue before you assembly the Zener diode D1 on the PCB.
The representation of the diode on the silk layer is wrong.
The lead indicated by the white band is not the cathode, as it usually should be.
It is instead the anode.
Please keep that in mind before soldering the zener diode in place, otherwise
it won't be possible to tune the voltage reference generator on the right value.
