VREF STM32G474QE

[Erwin_N]

For the 

STM32G474QE

 

i read that the VREF is either 2.048V 2.5V or 2.9V.

is this the maximum voltage the ADC can read in single ended and in differential mode?

 

so if i have a signal that is max 2.9V and min 0V. Will this work?

 

or is the VREF the middle voltage. so when my signal is 0V, the ADC voltage is 2.9V and when my signal is max, the max voltage is the VCC ot the STM32

[STTwo-32]

Hello @Erwin_N 

The 3 values are just the 3 output voltages supported by the Internal voltage reference buffer VREFBUF. For the Conversation voltage range it should always be between 0 and Vref+ as mentionned on the Datasheet - STM32G474xB STM32G474xC STM32G474xE - Arm® Cortex®-M4 32-bit MCU+FPU, 170 MHz / 213 DMIPS, 128 KB SRAM, rich analog, math acc, 184 ps 12 chan Hi-res timer

Best Regards.

STTwo-32

 

[Erwin_N]

Hello,

 

thanks for the fast response

 

So, what value is VREF+ then? is it standard the supply voltage?

and for clarification, those 3 output voltages are just reference voltages who can be used for other purposes.

[Erwin_N]

I read that VREF+ supports 2.048V 2.5V and 2.9. so i read that as if the VREF is one of those 3 voltages.  so the conversion voltage range goes from 0 to one of those 3 voltages right?

[STTwo-32]

As you can see on the tab 66 of the same datasheet i've mentionned before Vref+ is equal to VDDA if VDDA < 2V and Vref+ is between 2 and VDDA if VDDA => 2V.:

PS: VREF+ can be provided either by an external reference lower than VDDA of by an internal buffered voltage
reference (VREFBUF).

Best Regards.

STTwo-32

[Erwin_N]

So. You say that VREF+ can be anything in between  2V and the supply voltage (if it is bigger than 2V), but you also say that VREF+  can be provided by an internal buffered voltage.

 

Also, why are there 2 VREF+ connections
i

i am a little confused