Is it possible to give external reference voltage to STM32L431RCT6 microcontroller ?

[HP P.1]

I tried to give external reference voltage to STM32L431RCT6 microcontroller using precision voltage reference IC. But the controller is not taking any external reference voltage. Is it possible to give external reference voltage to STM32L431RCT6 microcontroller?

I have five STM32L431RCT6 microcontrollers, without any external reference voltage the "VDDA/VREF+" pin of each controller is showing different voltages. Is there any configuration or setup procedure to set the internal reference voltage? (I need all the controllers with same reference voltage)

or is there any way/procedure to provide an external reference voltage?

[gbm]

VDDA/VREF+ is an external analog power supply AND reference voltage input. It's NOT an output. It must be connected either to digital power supply voltage or your preferred, dedicated, stable and well-filtered analog power supply, simultaneously serving as Vref.

Read the pin description in the documents - it's quite clear. There is no point in measuring the voltage of a disconnected VDDA pin, as it's not an output.

[HP P.1]

Thanks for the information. Is it possible to give external reference voltage to this particular microcontroller? (STM32L431RCT6)

[gbm]

Yes, but the same voltage is used as VDDA and VREF. It may be, for example, precise 3.0 or 3.3 V, from different regulator than the one used for VDD.

[waclawek.jan]

> Is it possible to give external reference voltage to this particular microcontroller? (STM32L431RCT6)

No.

Only in the 100-pin packages, where VREF+ and VDDA are separate.

JW

[HP P.1]

Thank you.