STM32G0B0KE Input voltage range when using Vrefint

[DiBosco]

I'm trying to decide what G0 STM32 part to use on a brand new design. One of the requirements is to have six channels of ADC. The datasheet talks about the range of input voltage being Vssa <= Vin <= Vref+. However, on the 32-pin part, there is no Vref+ pin. So how does it work on that part? There's nothing obvious (to me at least) in the datasheet that clarifies this. I'm assuming that Vref+ in this case is Vrefint, but y'know, assumption is the mother of all screw ups.

So, is it thew case that if you're using Vrefint, the maximum input voltage to the ADC is Vrefint which is about 1.2V so in the end you only have 0-1.2V as an input range for the ADC?

Many thanks.

[TDK · Accepted solution]

For parts without a VREF+ pin, it is tied internally to VDD/VDDA.

From the datasheet:

 

VREFINT cannot be used as an input voltage for VREF+, despite the similar name. It's just a ~1.2V output that is tied to an ADC channel.

[DiBosco]

OK, thanks. Appreciated. I have finally found in the reference manual where that is stated.

[DiBosco]

I do think it's a bit weird that the reference to this is in the power secrtion not the ADC section. Sometime's STM's documentation leaves a bit to be desired.