Hi support,
I have a question about the behaviour of the PMIC PF3000 and the IMX7.
I work with a PICO-IMX7 from TechNexion. I can plug this SoM either into a kit (PICO-PI) or onto a custom board I've made myself.
My problem is that it doesn't boot when I plug it into my custom board, but it boots just fine on the kit. By connecting an oscilloscope, I can see that it tries to boot continuously but it doesn't succeed.
In this document: https://www.nxp.com/docs/en/data-sheet/PF3000.pdf, you can find this image showing the different start-up timings
So I measured these signals on my PICO-IMX7 to be able to compare. Below you will find two oscillograms: the first is the behaviour when I plug the PICO-IMX7 into the kit and the second when I plug the PICO-IMX7 into my custom board.
VIN = yellow
VSNVS = purple
PWRON = blue
RESETBMCU = green
The sequence on the kit is identical to what is shown in the datasheet.
However, for the second oscillogram, the blue signal (PWRON) does not remain in the high state. We only see a pulse and not an edge.
The PWRON pin is an input for the PMIC and so it's the IMX7 that has to set this pin high but it doesn't manage to do so.
I've looked for documentation on how this pin works for the IMX7, but I haven't found much, which is why I'm writing to you here.
Do you know why the IMX7 cannot keep the PWRON pin high?
Thank you in advance
Best regards.
