TPS65982 (USB 3.0 signal not worked)

Carol Chen

Other Parts Discussed in Thread: HD3SS3212, TPS65982

Hi there,

Wish one of you can help below issue. Thanks.

The Macbook connects with USB-C Digital AV Multiport Adapter firstly, and then USB-C Digital AV Multiport Adapter connects with the PC board built-in TPS65982.

Everything goes well on detecting USB 3.0 signal (R/W speed: over 60 Mbps). But it is odd when the Macbook connects with the PC board built-in TPS65982 directly, it can only detect USB 2.0 signal (R/W speed: under 60 Mbps)

You may check the test thru below link.

https://www.youtube.com/watch?v=6YLtHEv2m64

Where is the problem?

The USB SS Mux has built the HD3SS3212 IC. Would it be better to build USB3.0 Redriver IC on PC board beforeHD3SS3212 to improve the USB 3.0 signal?

Note:

Your Firmware version: TPS65982-EVM_Flash-Image_RTM.BIN

Type C connector is checked ok no matter up or down. HD3SS3212 is manually opened.

over 10 years ago

0 Brian Berner over 10 years ago

TI__Mastermind 30310 points

Thank you SO much for documenting your test with a video! You have no idea how rare this is and how helpful it can be to debugging remotely.

Please allow me some time to review the video and understand your use case.
Also, do you have a schematic of your PCB or at least a block diagram I can review?

The HD3SS3212 is not installed on our Dock reference design, so I will need to loop in some friends from another product line.

0 Carol Chen over 10 years ago in reply to Brian Berner

Prodigy 70 points

Brian,

Yes, I may provide the PCB's schematic. Please see the attachment.

TYPE C sch.pdf

0 Brian Berner over 10 years ago in reply to Carol Chen

TI__Mastermind 30310 points

Carol,
Sorry, you posted the schematic right before the beginning of a long holiday weekend in the US.
I marked this post so that I can take a good look tomorow and reply.
Thanks for your patience.

0 Brian Berner over 10 years ago in reply to Carol Chen

TI__Mastermind 30310 points

Carol,

The video is very sad, but mostly because of the music.

I think because you posted the video, it shows me 1 very important thing: In both cases, you are going through the Mux on your PCB with the TPS65982 handling PD communications. The only variable between the 2 test cases appears to be the cable.

The TPS65982 isn't being used to control the HD3SS3212, so it wouldn't matter what the TPS65982 negotiates. If your board were wired for DisplayPort, I would be considered you have negotiated 4-lane DP Mode, but that isn't the case here. If the voltage on SEL is the same in both tests, then my best guess is the Type-C cable you cut open isn't providing very good data rates.

0 Carol Chen over 10 years ago in reply to Brian Berner

Prodigy 70 points

Brian,

Thank you very much for prompt response. I see, we might have the Type-C cable unshielded causing the communication worse.
Yes, we are buying a new good cable and will test again.

Let me report while next test is done. Thanks a lot.

0 Brian Berner over 10 years ago in reply to Carol Chen

TI__Mastermind 30310 points

Carol,

If you don't mind my asking, what software are you using to test USB throughput speeds?

The GUI looks very intuitive with big, bright animated display!

0 ALEXANDER FEINMAN over 10 years ago in reply to Brian Berner

Prodigy 60 points

This may sound silly, but have you actually tried to reverse the cable (upside-down)? I don't see any logic for handling the reversal. Could it be that in the first case you had the correct cable orientation and in the second you didn't?

0 Carol Chen over 10 years ago in reply to Brian Berner

Prodigy 70 points

Brian,

We are using Blackmagic Disk Speed Test. Wish it helps.

0 Carol Chen over 10 years ago in reply to ALEXANDER FEINMAN

Prodigy 70 points

Alexander,

Yes, we did check the cable reversal (upside-down), but got same test result.

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TPS65982 (USB 3.0 signal not worked)