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STM32f7 - ripples on 5.0V supply

Question asked by RE.KH on Sep 18, 2017
Latest reply on Nov 29, 2017 by Eugene Solo

I have noticed that STM32F7 microcontroller generates a digital noise (see the figures. It is not from transmission lines and bursts are repeating every 16ms) on the 5.0V supply voltage. 

I have observed this using both Discovery and Nucleo boards.

I have seen this using external power supply and the power over USB.

I have also tried different sample codes. It actually does not matter what code you run, because even before I start the code in my debugger, the ripples can be observed. The only time, I do not see the ripples, is when the microcontroller is kept in reset, or when I remove a jumper to power it down.

I have also noticed that, after couple of resets, the noise sometimes disappear. It comes back if I reset again.


Anyone else who has observed this issue?  Any thoughts?