DP83TC814S-Q1: Cable lengths

Hi Didrik,

We only test our 100BASE-T1 PHYs for up to 15m cable length. 

Best regards,

Greg

Hello Greg,

Thats unfortunate, I found in this paper https://www.ti.com.cn/cn/lit/an/snla420a/snla420a.pdf references to a 100 meter cable length in the table on the second page, but I couldn't find any other references to where that number came from and few datasheets mention any limits.

Regards,

Didrik

Hi Didrik,

I will check with the team that completed the testing for the SNLA420A document to determine the configuration used to achieve those cable lengths. Although the IEEE standard for 100BASE-T1 is 15m, the DP83TC814S-Q1 device can likely support longer lengths than that. 

What is your end application for the PHY? Is it possible to use a standard Ethernet PHY? They support much longer cable lengths. You can also use the EVM boards for the 100BASE-T1 PHYs to determine if the required cable length is supported for your specific application.

Best regards,

Greg

Hi Greg,

That would be great, we intend to use 100BASE-T1 with PoDL or a hybrid version (with separate power conductors) for a real time locating system in underground mines. Our beacons are tiny and planned to be be delivered already attached to cables, and terminating so many conductors adds both area to the PCB and production complexity so we want to avoid standard ethernet.

I will have a look at the EVM boards.

Regards,

Didrik

Hi Didrik,

Thank you for the additional information. What is the data rate requirement for your system? The DP83TD510E, a 10Base-T1L PHY, supports long distance cable reach. In addition, 1000BASE-T1 devices with Type B connection can support up to 40m cable length.

The 100BASE-T1 PHYs may be able to support longer cable lengths, but we can only guarantee them to work for up to 15m. If I come across any additional information regarding supported cable lengths, I will update you.

Best regards,

Greg