HD3SS6126: Interface forum

Ishay Shavit24

Part Number: HD3SS6126

Greetings,

I'm going to connect a host (NVidia Xavier) through HD3SS6126 to two USB3 devices.

In the datasheet, it is mentioned that "All of the interfaces the HD3SS6126 device supports require AC coupling between the transmitter and receiver", and later-on in that paragraph (8.2.2.2) it says: " The placement should be along the TX pairs on the system board..."

I don't understand this last sentence.

Please see the schematic I've prepared, and inform if need to move the coupling to channels A and B.

over 6 years ago

0 David (ASIC) Liu over 6 years ago

TI__Guru**** 177301 points

Ishay

Are the NVidia and Camera on the same design or are you connected the HD3SS6126 connected to USB connectors?

Would you please provide a block diagram of your design?

Thanks

David

0 Ishay Shavit24 over 6 years ago in reply to David (ASIC) Liu

Intellectual 310 points

Attached is a block diagram.

0 Ishay Shavit24 over 6 years ago in reply to David (ASIC) Liu

Intellectual 310 points

Attached is a block diagram.

Please inform if AC coupling should be on A,B or on C, and if should be on Tx/Rx or both.

Thanks.

0 David (ASIC) Liu over 6 years ago in reply to Ishay Shavit24

TI__Guru**** 177301 points

Ishay

For both A and B:

0.1uF AC couple on TX

0.33uF AC couple on RX (optional) or DC couple on RX

For C:

DC couple on both TX and RX, this includes the XAVIER SOM.

Thanks

David

0 Ishay Shavit24 over 6 years ago in reply to David (ASIC) Liu

Intellectual 310 points

Thanks David,

What about the HS (DM/DP), I saw designs with AC coupling. Is it needed, on which ports?

Thanks in advance, Ishay

0 David (ASIC) Liu over 6 years ago in reply to Ishay Shavit24

TI__Guru**** 177301 points

Ishay

HS (DP/DM) is DC couple only.

I also like to point out that the HD3SS6126 is a passive switch only with no re-driver capability. For this design, if the carrier board is part of the host, please make sure it does not exceed the loss budget as defined by the USB spec: https://usb.org/sites/default/files/USB_3.1_Loss_Budget_Rev_1.0_-_2015-03-02.pdf.

Thanks

David

0 Ishay Shavit24 over 6 years ago in reply to David (ASIC) Liu

Intellectual 310 points

Thanks for the excellent support!