Passing USB C PD through pcb . Only one orientation works!

Thread Starter


Joined Dec 23, 2008
Hi all.
I have a problem with USB C Power Delivery that has me stumped.

I wish to use a PCB to serve as a female-to-female USB C adapter, to connect a PD Power Bank(PB) to a USBC to DC cable (plug has PD circuit inside, similar to this

So my board has 2 USB C female receptacles that connect to each other via GND, VBUS CC1 and CC2. To my understanding, this would be all that is needed to pass on PD feature to the downstream device.
The issue is that this only works when I connect a cable from PB to this PCB in one specific orientation. No PD feature in opposite orientation.
I have triple-checked the board, and the results are consistent across other boards so assembly issues are unlikely.

Do I need any extra pins to connect two USBC cables to each other and pass on the PD feature?

If I use an adapter such as this to connect PB -> USBC cable -> adapter in link -> USBC to DC cable again I only get voltage on DC output in a single orientation, so this adapter has the same limitation as my pcb.

To add to the mystery I had a cable laying around that I believe is this one through which I can pass the PD signal on both orientations. Could this be an issue of quality of conectors\routing\etc or do I need some extra electronics to make it work and this Ugreen cable has it?

Any help is quite welcome. Tks