unfortunately…
… an ohmic load (Thank you Axel) shows the same behavior (spikes on Vout) as seen in the previous post. Fortunately I’ve spent some space on the pcb for an optional filter that has now become mandatory.
The spikes do not change with load or input voltage. I took a closer look and they are much less random compared to what the screenshot looks like. They’re expected transient responses to the switching. currently they’re around +- 1,5V which is too much.
Unfortunately the additional inductor and capacitor for the filter where not part of the part delivery I’ve received. The delivery date is changing once a week and is oscillating around 30th of march.
But in the meantime I still can try to get the arduino running. It has it’s own voltage regulator and an additional capacitor at the input, so the currently “dirty” Vout will not be an issue.