SN74AXC8T245: As RGMII Buffer

sudarshan kr

Part Number: SN74AXC8T245

Hi,

In my design i need to connect RGMII signals b/w two chipsets which are having more than 6 inches, in this case can the SN74AXC8T245 act as a buffer and provide option increase the length limitation of 6 inches.

Thanks in advance

Sudarshan

over 2 years ago

0 Joshua Salinas over 2 years ago

TI__Mastermind 22230 points

Hello Surdarshan,

In this application, would both supplies on the AXC8T245 be running at 3.3V or around this voltage?

Regards,

Josh

0 sudarshan kr over 2 years ago in reply to Joshua Salinas

Prodigy 40 points

Hi Josh,

Yes, on both the sides we will be using 1.8V

Regards,

Sudarshan

0 Joshua Salinas over 2 years ago in reply to sudarshan kr

TI__Mastermind 22230 points

Hello Sudarshan,

Thanks for confirming. Given both supplies will be 1.8V, the output current drive will be around 8mA. See image below. This should be good enough to help with the 6 inches of length between the two chipsets.

Regards,

Josh

0 sudarshan kr over 2 years ago in reply to Joshua Salinas

Prodigy 40 points

Hi Josh,

I think my question is wrongly interpreted. My question was without the buffer itself the chipsets are capable to be driven among themselves for the length of 6 inches b/w them. If we add this buffer then can the length which can be handled b/w the FGPA and the RGMII chipset be increased to more than 6 inches

Regards,

Sudarshan

0 Joshua Salinas over 2 years ago in reply to sudarshan kr

TI__Mastermind 22230 points

Hello Sudarshan,

Thank for clarifying. Yes, adding this buffer can increase the length to more than 6 inches. However, we do not guarantee the AXC8T will meet RGMII timing specs. It's best if this device can be tested in a prototype board and see if this meets your systems requirements.

Regards,

Josh

0 sudarshan kr over 2 years ago in reply to Joshua Salinas

Prodigy 40 points

Hi Josh,

Thanks for clarification.

Regards,

Sudarshan

0 Joshua Salinas over 2 years ago in reply to sudarshan kr

TI__Mastermind 22230 points

Hello Sudarshan,

In my previous response I mentioned we don't guarantee the AXC8T meets RGMII timing specs.

TI just released the TXV0108-Q1, a voltage translator that meets these timing specs. See image below.

Wanted to make you aware of this product. Please let me know if you have any questions.

Regards,

Josh

0 sudarshan kr over 2 years ago in reply to Joshua Salinas

Prodigy 40 points

Hi Josh,

Thanks for the update. Currently we have optimized the design within 6 inch to take care of the RGMII issue. But still this will be useful information for our future requirements. We will make note of it

Regards,

Sudarshan

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SN74AXC8T245: As RGMII Buffer