Other Parts Discussed in Thread: BOOSTXL-TPS65218
Hi,
we upgraded a stable custom AM335x design from TPS65217D PMIC to TPS65218D0. The boards boots fine ti linux kernel 4.14.79 from processor sdk. Rebooting via "reboot" is fine. But trying to poweroff just reboots the board. I found that this - or something similiar - was an issue with prior silicon of the PMIC. But we have the latest - chipid is 5.
Design is based on http://www.ti.com/lit/ug/slvuaa9a/slvuaa9a.pdf.
I posted this issue here https://e2e.ti.com/support/processors/f/791/p/821927/3042426
To test poweroff function I finally added a test funtion in our bootloader to minimize the software influence on the issue.
I ended up playing with the AC_DET pin. My setup supplies our board via 5V USB power. This pulls down AC_DET pin - as intended. When I remove the external 5V our board runs from battery and AC_DET is pulled high. I noticed that the board goes to OFF state after calling poweroff command when AC_DET is high and reboots when AC_DET is low. From the datasheet I expected that the PMIC shuts down independant of AC_DET. Just a falling edge (!) on PB or AC_DET should do the wakeup. But here a low level on AC_DET does not allow shutdown but causes a reboot.
This looks strange. Or did I misunderstand the AC_DET pin?
Any hint?
Regards,
Matthias