VREF Internal voltage reference G431 series

[CrazyChel]

Hello,

Can anyone suggest whether or not I need to connect external capacitors to the VREF+ pin if I plan to use VREF only for the onboard DAC?
Could this be a hardware problem?
STM32G431CBT6. The problem is that on the oscillogram I see oscillations with an amplitude of approximately 490 mV on the VREF+ pin. This is when Scale 2 is set to 2.9 V. If I reduce to 2.5V, the swing will be almost 1V overall. Nothing but the 1:10 oscilloscope probe is connected to the VREF+ pin on the board.
Below are the screenshots.

 

 

 

 

[TDK · Accepted solution]

Yes, it needs capacitors if you are using the DAC, per the datasheet and the hardware design guide.

[CrazyChel]

Thank you! The question is closed.
I have already connected 0.1 µF and 20 pF. Now I can switch between different ref values.

[waclawek.jan]

> I have already connected 0.1 µF and 20 pF.

I don't think these are the values required by the datasheet.

JW

[CrazyChel]

Thank you, I also noticed that this is not enough, I will increase it.