MKE02Z32VLC4 - ADC reference voltage range

[____]

Hello,

i have a question about the microcontroller MKE02Z32VLC4.
Regarding to the Datasheet, the Voltage for V-DDA shall be between (VDD – 0.3V) and (VDD + 0.3V).
V-REFH is then on the same potential since its on the same pin (for QFN 32 package).

It looks like there is no option to power the controller with any voltage arround 5V, and use a external ADC
reference with +3.0V (for example).
Am i right with that assumtion, or have i missed something?

[diego_charles]

Hi @____ 

I hope you are doing well!  If you power the MCU with VDD of 5V,  the VDDA  (analog supply)  should be in the  (5.0– 0.3)v  and  (5.0 +  0.3)v   range. 

The external reference pins VREFL and VREFH, should also follow VDDA and VSSA,  So, if VDDA is 5V,  the external VREFH should be at 5V too. And this is also restrictive because VREFH and VDDA are internally connected.

So , as you point out : there is no option to power the controller with any voltage around 5V, and use a external ADC reference with +3.0V 

For design reference you could  check the  FRDM-KE02Z40M schematics. 

All the best,

Diego.