[C6678] Can external signals drive unpowered SERDES on SGMII pins?

RandyP

If the C6678 is not yet powered up, is it acceptable for the AC-coupled SGMII SERDES lines to be driven by an external device?

The external device is a GigE switch that has a differential output of 400mV peak.

Regards,
RandyP

over 10 years ago

0 Bill Taboada over 10 years ago

TI__Mastermind 42545 points

Hi Randy,

The IO cells in the C6678, including the SGMII interface, were not designed to be driven if the supply voltage for the cell was not present. Driving the SGMII receive pins before the power is present could damage the part. If the switch must be active, SGMII signals would have to be disabled until the power to the C6678 is present.

Regards, Bill

0 RandyP over 10 years ago in reply to Bill Taboada

TI__Guru* 84110 points

Bill,

Perfect. I will make this very clear to them.

Thanks,
Randy

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[C6678] Can external signals drive unpowered SERDES on SGMII pins?