Hi guys! Sorry for the huge delay, but Ifiinally got some time to take some measurements and here are the results.


This is how the system looks at no load. Quite stable.

Here I have the load increased to around 0.9A. It is still stable at 5V. (i also added the voltage across the inductor)

As you can see. As soon as I increase the current over 1A the voltage starts dropping. So does the feedback voltage. I will add more pictures both zoomed in and out but these are the most relevant.


I tried once again to pinpoint the issue but I just cannot get to it. Any ideas?

 

I've used several TI buck and boost converters, and one thing I have found which may be of some use:
They are particularly sensitive to the position of the capacitor on Vin. Unless it is right next to the IC, it works in "bands". There will be certain bands of output current where it performs perfectly, and other bands where it won't do as it is told. The waveforms you post remind me of the waveforms I was getting when I was trying to get an LMR38010 to work.
With 1uF ceramic right next to the input pin, it's been as good as gold, and I've made a few hundred since I found out.

 

As I have mentioned, along with several others, every part of a switcher supply is a component, and thus has an effect on performance. Ian0 makes sense with the comment. Connection voltage drop and ground loops matter a whole lot in switchers!!

 

When I was working on the LMR38010, I thought I had the input decoupling capacitor near enough (it was about 20mm from the IC) but it was not happy until I moved it MUCH closer.

 

Hello and thank you for your answers. Here is my current layout:


The highlighted capacitor and the other two below that are my input capacitors:



C602, C603 and C613 in the picture above.
You suggest it might help if I move all of them in the space I marked with green here?



So as close as possible to the input pin of the IC?

I have tried to respect as much as possible the recommandation from the datasheet:



Thank you both for your input and help!