TPS25751: Selection of USB HUB PD controller

Hello, 

Find my responses below

Kaji@PAN said:

What kind of device is appropriate to use in a USB HUB?

You can use the TPS25751 here as well. It has the ability to control external MUXs and redrivers via GPIO

Kaji@PAN said:

If you have any materials that explain the PD control flow (sink/source switching, etc.), please provide them.

This is a good introduction document into the basics of USB-C. https://www.ti.com/lit/SLYY109 

Kaji@PAN said:

I am considering products from MediaTek and Qualcomm as the processor for SYSTEM A, but is there a possibility that USB PD cannot be realized depending on the processor?

The processor should not be relevant for the USB-C port and PD capabilities. As long as you can provide adequate power (i.e. advertise 20V and being able to supply 20V), data, and video as advertised