I have SND9039 powering a Cherrytrail SoC. During most of the use cases it works as expected however, there is this one case where I'm having trouble figuring out whats going on.
Application is not battery powered.
- With a Input voltage of 3.5V (Vsys) turned ON, a brownout on the input below 2.5V (datasheet value) should ideally reboot the PMIC.
- A brownout from 3.5V to ~2.2V at Vsys for 4ms does not reboot the PMIC everytime. There are instances where it does reboot and sometimes it doesn't.
- a trigger on PWRBTN turns the PMIC ON in cases where it doesn't reboot.
What could be a possible cause?
Are there any specific signal that needs to be looked at?
Does the PMIC not see the rising edge on Vsys? Brownout time is ~4ms.
