This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

SN74AXC8T245: level shifter for differential RGMII interface

Part Number: SN74AXC8T245

we are using 1.8 logic level and 3V3 logic level between two system and interface over RGMII interface. And need to support 800Mbps data rate at least.

Question are;

I think we have to use level shift for Tx/Rx Clock and Tx/Rx En but the others are all differential so I don’t think we have to use eight Rx/Tx differential data line. Is it correct?

If we have to use level shifter for eight data transmission line, please let me know why? And what issue happen w/o level shifter.

  • Hi Jaroon,

    I have known the RGMII to be at 125Mhz or 250Mbps data rate but not at 800Mbps.

    SN74AXC8T245 cant support 800Mbps data rate for the 1.8 <>3.3V translation. We also do not have devices which can support differential signaling( +/ - ).

    considering Interface portfolio on different interfaces including differential signaling.

    The devices might not work without level shifter unless the threshold of the 3.3V devices are above 1.8V.

    http://www.ti.com/interface/overview.html