DP83TC811S-Q1: How to connect ethernet pins to unidirectional connector (100Mbit)

Valentinas Pancerovas

Part Number: DP83TC811S-Q1
Other Parts Discussed in Thread: DP83TC811, DP83TC811EVM

Hello!

We are using a normal RJ-45 connector and therefore we have TX+/TX- and RX+/RX- pairs.

Your IC has bidirectional pins so we dont understand how TX and RX should be connected separately. Can we use channel A for TX and channel B for RX?

Or do we need to implement a hardware based uni-bi direction converter circuit?

10 months ago

0 Melissa Chang 10 months ago

TI__Genius 10710 points

Hi Valentinas,

The DP83TC811 is a Single Pair 100Base-T1 ethernet device. The connector you are showing appears to be for Standard Ethernet 10Base-Te or 100Base-TX device.

The connector we use for our DP83TC811 EVM can be found here: https://www.te.com/usa-en/product-9-2304372-9.html

If you want to convert between 100Base-T1 and 100Base-TX, you can purchase our DP83TC811EVM: https://www.ti.com/tool/DP83TC811EVM

Best regards,

Melissa

0 Valentinas Pancerovas 10 months ago

Intellectual 410 points

Hello Melissa,

Thank you for explaining. Now i get the differences between T1 and TX.

Your EVM schematics do not support search function, i am having trouble understanding how and where does the conversion really happen?

+1 Melissa Chang 10 months ago in reply to Valentinas Pancerovas

TI__Genius 10710 points

Hi Valentinas,

It is a significant change. Our media converter EVM does the conversion from 100Base-T1 to 100Base-Tx by connecting the DP83TC811 to another PHY, the DP83822, through RGMII. The DP83822 supports standard Ethernet so it can be connected directly to the RJ45 connector.

You can find the altium design files here: https://www.ti.com/tool/DP83TC811EVM

Best regards,

Melissa

0 Valentinas Pancerovas 10 months ago in reply to Melissa Chang

Intellectual 410 points

Hey Melissa, i appreciate your help!
Would it be possible to just use a bidirectional differential to single ended converter for TX and T1 conversion ?

Something like this: www.ti.com/.../thvd1500.pdf

0 Melissa Chang 10 months ago in reply to Valentinas Pancerovas

TI__Genius 10710 points

Hi Valentinas,

Do you want to convert your 100Base-T1 signal into a standard ethernet signal or are you trying to do Galvanic Isolation and send the 100Base-T1 signal through only a single pair of wires?

If you are trying to convert from 100Base-T1 to standard Ethernet, the only solution I can think of would be to do something to our Media Converter circuit I mentioned above. Using a bidirectional differential to single ended converter would not work.

If you want to do Galvanic Isolation, we may have some reference design I can send you but I'm not sure it has been tested on the DP83TC811.

Best regards,

Melissa

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DP83TC811S-Q1: How to connect ethernet pins to unidirectional connector (100Mbit)