TUSB321: TUSB321RWBR

K:

1: you need 100nf AC cap on USB3_TX1/TX2.

2: need ID pin to control Vbus switch.

3: why there are two USB3_CC1/CC2?

Regards

Brian

Hi Brian. 1. TX Caps are at the connector and the host processor. 2. My understanding of ID is for using OTG mode. For this particular USB connector, we don't support OTG so should be fine right? 3. Regarding the CC lines... If you're saying only "CC1" OR "CC2" should be used but not both, that's probably the problem right? Thank You -K

This is actually how the CC lines are set up. The "Variant" selection was turned off in the first capture.

For ID, in type-C DFP or DRP, ID is used to turn on Vbus . ID is high until an UFP devices was attached , then ID goes low and turn on Vbus switch.

so ID here is not for OTG.

Regards

Brian

Hi Brian,

Ok no problem. What about the CC lines?

Thank You

-K

yea, CC lines are fine.

Regards

Brian

One last question. If the TX/RX  Diff Pairs we're swapped on the host side of the MUX, would it cause this scenario? I'm just curious because I don't have a good way to test this. Thanks -K

not very clear, what kind of swap?

Hi Brian,

i.e. The respective TX/RX diff pair we're swapped with each other on the "A" port of the MUX. If this were the case, it would not work at all but coincidentally that is my issue when the CC lines are both connected normally.

-K

you can swap TX/RX for layout purpose, but TX should connect to TX of host, RX connect to RX of host.

Regards

Brian

Just wanted to update this. I got it working but ended up being an issue with VBUS_DET. All is good now. Thank You