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HD3SS3212: Question about SS polarity inversions

Prodigy 20 points

Replies: 2

Views: 90

Part Number: HD3SS3212

Hi team,

I'm trying to implement a usb type-c UFP by using HD3SS3212 as the switch between my device(cypress's FX3 usb controller) and the type-c connector, as the picture, the connector's ss pins connected to HD3SS3212's B and C ports, and FX3's ss pins connected HD3SS3212's A port.

But FX'3 ss pin order is not the same as HD3SS3212, I need to invert the polarity of HD3SS3212's A port.

I know that HD3SS3212 is a passive switch, and USB3 can detect polarity during link training, it's safe to ignore the polarity just routing the line from FX3 to HD3SS3212

But from HD3SS3212's datasheet Page 10, "The HD3SS3212 can tolerate polarity inversions for all differential signals on Ports A, B, and C. Take care to ensure the same polarity is maintained on Port A versus Ports B/C."

What does the last sentence mean?


and will my circuit work correctly?

  • The HD3SS3212 is a passive switch that supports different standard and some standards may not support polarity swap function as USB3. 

    For USB3, there is no issue with the polarity inversion on USB3 since the physical layer is able to detect and compensate the the polarity inversion after every connection event. You can follow the schematics from TIDA-00882 without any concern.

    Thanks

    David

  • In reply to David (ASIC) Liu:

    Got it! Thank you very much!