0
\$\begingroup\$

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?

\$\endgroup\$
  • \$\begingroup\$ Don't see any need to do anything with them. I might be tempted to put an LED on the board to show they're powered up (which would signify the host has seen the pull-down resistors and activated VBUS power). \$\endgroup\$ – Finbarr Jun 24 at 11:20
  • \$\begingroup\$ So, do you mean to leave them Simply unconnected? \$\endgroup\$ – g.mezzina23 Jun 24 at 14:11
0
\$\begingroup\$

Yes, you should follow a specific procedure to connect VBUS to your device. As you said, your "self-powered IC" will provide Dp and Dm (as UFP). So, if you want to follow USB specifications, operations of Dp/Dm lines should be conditional with the presence of VBUS. For more details and references, see this answer.

| improve this answer | |
\$\endgroup\$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.