HD3SS3220: DFP Eval Module

John Monaghan

Part Number: HD3SS3220
Other Parts Discussed in Thread: TUSB211,

In the HD3SS3220 DFP Eval module, there is a redriver for the USB2 signals (TUSB211), but there is not a redriver for the USB3 signals? Why is there no redriver for the USB3 signals?

over 3 years ago

0 Brian Zhou over 3 years ago

TI__Guru*** 145355 points

it just depeds on your PCB layout If needed, you can add USB3 redriver as well.

Regards

brian

0 John Monaghan over 3 years ago in reply to Brian Zhou

Prodigy 20 points

thanks for the reply, but please provide a more direct answer - why was the USB3 redriver not needed in that eval board?

0 John Monaghan over 3 years ago in reply to John Monaghan

Prodigy 20 points

... what about its PCB layout caused it to not be needed? Also, please direct me to any literature like app notes that may clarify how to determine if it is needed.

0 Brian Zhou over 3 years ago in reply to John Monaghan

TI__Guru*** 145355 points

muxes and redrivers have different applications. Redriver is needed when the PCB on the board is too long and caused lots of loss more than CPU or SOC can handle.

You can look at white paper SLYY121 from ti.com

HD3SS3220DFP module is designed to test type-C USB3, actually TUSB211 is not needed here.

Regards

Brian

0 John Monaghan over 3 years ago in reply to Brian Zhou

Prodigy 20 points

Thanks for the whitepaper reference and clarifications! What do you mean by "designed to test type-c USB3" and why does that mean TUSB211 is not actually needed in the DFP eval board?

0 Brian Zhou over 3 years ago in reply to John Monaghan

TI__Guru*** 145355 points

HS3SS3220 is a mux only for USB3 signal. We put USB2 redriver here is just to promote TUSB211 device, customer can either use it or not for their system design. By the way, input and output of TUSB211 are routed together on PCB , so customer can just remove it if don't needed.

Regards

Brian

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HD3SS3220: DFP Eval Module