I'm designing a breakout board for a USB2.0 Type-C connector.

The final board, which will contain the connector breakout circuit, should work as "device", and so as Upstream Facing Port, or UFP. It will also be equipped with a self-powered IC (no need for Vbus) that provides dp and dn lines to the connector.

At the moment, I know how to treat the CC lines (via 5.1kOhm pull-down resistors) but I still don't understand how to connect (or how to use) the VBUS lines.

In this kind of device, can I leave the VBUS lines unconnected or I should follow some specific procedure to connect them?

Sincerely, GM