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?