USB power on BelaMini should come from Vsys 5V

[giuliomoro]

On the PB:

1. VBUS.RAW (the 5V in from the µUSB on the PB) is connected through a ferrite bead (FB1) to the VIN.USB signal (broken out on P1.07 and labelled USB1.VIN). This is also connected to ball J16 of the BGA, which is USB0_VBUS. This has the following consequences:

• if power is supplied through USB0 (µUSB on the PB), then USB1.VIN will also be powered.
• if power is supplied through USB1 (header), then the AM335x will think that USB0 has power.

2. the OSD335x checklist (https://octavosystems.com/app_notes/osd335x-schematic-checklist-am335x/) says

USB VBUS Sense Input: USBx_VBUS is a voltage sense input and NOT a power output pin. Check that a valid voltage (>=4.4V) is present on the pin to enable the USBx peripheral.

3. the TPS65217 can allow large currents from input to the Vsys output, and ranges can be set in software:

4. Jason K is happy to review the amended design.

[giuliomoro]

This https://github.com/beagleboard/capes/blob/master/pocketbeagle/GamePup/GamePup_Cape_sch.pdf , according to Jason, "should do USB host right" (and uses a boost converter to generate the right 5V for USB regardless of the VIN/VBAT input voltage).

[giuliomoro]

from https://octavosystems.com/app_notes/osd335x-design-tutorial/osd335x-lesson-2-minimal-linux-boot/osd335x-lesson-2-usb-circuitry/

USBx_DP/DM: These are differential I/O pins that carry data.
USBx_DRVVBUS: The USB peripherals themselves cannot supply the necessary current to support Host mode. Therefore, the USBx_DRVVBUS output pin was provided to control external 5V power logic used to supply power to a Host port.
USBx_VBUS: This input pin is used to sense the voltage of the VBUS pin . For the USB peripheral to be enabled, a valid voltage (>=4.4V) should be placed on this pin.
USB_ID: The mode of USB peripheral depends on the state of this pin.