The USB0_VBUS signal is fail safe, so it should be ok to have 5V applied even when the AM335x is powered down. We noticed however that this appears to backfeed into the VDDA3P3V_USB0 rail. Here's a picture. The circled portion shows the VDDA3P3V_USB0 rail just before we powered up the device:
Is this expected? Is it ok?
