HD3SS3220: TX/RX pin connect

Jason Ciou

Part Number: HD3SS3220

Hi team,

My customer find a weird part in our datasheet and appnote

in the HD3SS3220 DFP Dongle Evaluation Module, https://www.ti.com/lit/ug/sllu237a/sllu237a.pdf?ts=1644496361176&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FHD3SS3220

Tx2p/n are connected to CRX2p/n .

in HD3SS3220 datasheet, TXP2/N2 are connected to TX2p/n.

My customer would like to know TX can connect to RX?

as I know TX should be connect to TX, RX should be connect to RX. Do I understand right?

over 3 years ago

0 David (ASIC) Liu over 3 years ago

TI__Guru**** 182061 points

Jason

HD3SS3220 is a passive mux so signal will be passed through without regard for RX or TX in both UFP mode or DFP mode. TX and RX are just naming convention.

Due to the nature of the design (USB connectors on both sides and layout) a swap between TX and RX was needed for the ease of layout. You can see the TX p/n pins are also connected to RX of the USB-A plug as well. If a swap is made it should be done on both sides of the device to ensure routing is correct. The datasheet shows typical USB-C application without dongle considerations.

Thanks

David

0 Jason Ciou over 3 years ago in reply to David (ASIC) Liu

TI__Expert 3600 points

Hi David,

So app note and datasheet are correct.

Jason

0 David (ASIC) Liu over 3 years ago in reply to Jason Ciou

TI__Guru**** 182061 points

Jason

This is correct.

Thanks

David

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HD3SS3220: TX/RX pin connect