Using USB3.0 and USB2.0 data lines on a Type-C connector separately

[rents]

Hi all,

My idea is to connect the USB2.0 lines to an USB2.0 hub IC and connect the USB3.0 data lines to an USB3.0 device. This way i will have 3 more USB2.0 ports. I have looked at some USB3.0 hub ic's (USB5533B and TUSB8040 to be precise) and it looks like there is two separate hubs for USB2.0 and USB3.0 inside the IC. I don't need more than one USB3.0 so i have come up with this.

Can i use USB2.0 and USB3.0 separetly? Will this couse enumarating issues for the USB3.0 device? Can i get away with this or do you recommend i should just use an USB3.0 hub IC? I have attached a block diagram;

[Aiy]

Hi there,
Here is a link to a whitepaper which discusses this kind of solution
https://numato.com/kb/usb-3-0-a-cost-effective-high-bandwidth-solution-for-fpga-host-interface/

Best regards

[rents]

Yea thank you. I didn't see this before. It's nice to see someone else thougth of this aswell

[spostma]

You can passively split an USB3.0 port into an USB2.0 only and an USB3.0 only port, but without Power Delivery so 5V bus only.
https://nl.aliexpress.com/item/1005005144932848.html

I have attached the schematic of a similar splitter PCB with a Type-C socket to the host and a dual Type-A socket to fixed USB3 and USB2 devices,
but the schematic has incorrect values for R90 and R91, which should be 5K1 and unpopulated, respectively for an upstream facing USB port.

Microchip AppNote AN1953 explains the required resistor values clearly.

[rents]

Thank you. Wouldn't have thinked that receive and transmit signals cross connected.