VDDA reading

[Zer0]

I have a problem regarding VDDA on my hardware piece, that has an STM32U535RET6 chipset. According to the documentation, this exact chipset, does not have an internal reference buffer, so I'm stuck to using the VDDA/VREFINT as they are for my ADC1-IN13 (Asynchronous clock mode dived by one, 12 bit resolution and a sampling time of 814 Cycles). The reading after the conversion for the ADC-IN13 using VDDA is 173 with an analog voltage reading of 0.137V. Now, using the analog to digital conversion formula, that would result in System voltage of around 3.24V , but in the chipset's documentation is said that that for the ADCs is around 1.62V if I understood correctly. Am I missing something in the documentation or am I just doing something wrong regarding the conversion?

 

[AScha.3]

You should take a DMM and see the real VDD (= VDDA , Vref+ ) ;

3.24V seems ok.

+

You CAN have the chip at 1.7V , and its still working... but you dont need to do that. :)

 

 

[TDK]

The data sheet excerpt you included says that if you use the ADCs, the VDDA must be 1.62 V to 3.6 V. Not just exactly 1.62 V. A value of 3.24 V is within that range.