DS110DF111: does DS110DF111 work with reversed P and N Trace?

Lin Lu

Part Number: DS110DF111

Hello,

we have built signal extender using DS110DF111 to extend the range of XFI signal. By one Product we connect positive trace of PHY/MAC to positive pin of retimer and negative trace of PHY/MAC to negative pin of retimer. Since we want to use the same extender for another product which has reversed polarity, it means negative trace of PHY/MAC to positive input of retimer, positive trace of of PHY/MAC to negative pin of retimer. Will the retimer still work?

Thanks

Lin

over 3 years ago

0 Lin Lu over 3 years ago

Prodigy 120 points

MAC (P Trace) -> Retimer (N Trace) -> PHY(P_Trace)

MAC (N Trace) -> Retimer (P Trace) -> PHY(N_Trace)

0 Lee Sledjeski over 3 years ago in reply to Lin Lu

TI__Mastermind 43795 points

Hi Lin,

Yes the retimer will work with reversed signal traces. It is also possible to invert the retimer output polarity with SMBus register control to improve routing on the PCB.

Regards,

Lee

0 Lin Lu over 3 years ago in reply to Lee Sledjeski

Prodigy 120 points

Hello Lee,

thank your for the reply! I just check the datasheet, it only says it is possible to inverter output polarity. Will it also be able to change the input polarity of Retimer? Since we want to habe the following connection:

PHY_Tranceiver (P) -> Retimer INAn -> Retimer OUTAn -> MAC_Receiver (P)

PHY_Tranceiver (N) -> Retimer INAp -> Retimer OUTAp -> MAC_Receiver (N)

Thanks

Lin

0 Lee Sledjeski over 3 years ago in reply to Lin Lu

TI__Mastermind 43795 points

Hi Lin,

The retimer inputs do not care if the P/N input signals are crossed. The polarity control in the retimer output driver is used to adjust for your signaling connections. This will ensure that the MAC_Receiver will get the correct P/N information.

Regards,

Lee

0 Lin Lu over 3 years ago in reply to Lee Sledjeski

Prodigy 120 points

Hi Lee,

sorry for the late replay, so it means in my case I don't need to reverse P and N at all, is it correct?

0 Lee Sledjeski over 3 years ago in reply to Lin Lu

TI__Mastermind 43795 points

Hi Lin,

Sorry for the late reply. You do not need to reverse the P and N signals at all. The retimer will work just fine.

If the MAC needs to have the correct polarity, there is a register to flip the P and N signals in the retimer internally. This eliminates the need to reroute the signals on the PCB.

Regards,

Lee

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DS110DF111: does DS110DF111 work with reversed P and N Trace?