HD3SS3220: TXp/n & RXp/n pull down resistors

Shmuel Davis

Part Number: HD3SS3220

On the development board there are 100K pull down resistors on the USB3_TX0N\P & USB3_RX0N\|P_C signals with an associated design note "R10, R11, R6 and R7 are placed for interoperability purposes with USB Vcm above 2V." - please could you explain. Can I assume that these are not required for a design with these signals are routed directly to a gate array on board ?

over 7 years ago

0 Luis Omar Moran over 7 years ago

TI__Genius 16150 points

Hi Shmuel,

C1, C2, C3, C4 R10, R11 R6 & R7 were placed in the HD3SS3220UFP-DGLEVM for interoperability cases, I mean, in some specific applications a higher voltage USB Vcm above 2V (up to 12V) is required, this is the reason these components were placed in the EVM. Basically, is depending of the application of the customer, in your case these components are optional (not required).

Best Regards,
Luis Omar Moran
High Speed Interface
SWAT Team

0 Shmuel Davis over 7 years ago in reply to Luis Omar Moran

Expert 2930 points

Thank you for this clarification !

0 Luis Omar Moran over 7 years ago in reply to Shmuel Davis

TI__Genius 16150 points

Hi Shmuel,

Would you mind to verify my answer, please? If further support is needed please open a new ticket.

Thanks,
Luis

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HD3SS3220: TXp/n & RXp/n pull down resistors