TJA1102

[martinsmith]

Hello, I’m getting confused by the TJA1102 single/dual phy ic.

The datasheet shows 2 full RMII ports, and it looks like each one controls a single pair of TRX_M & TRX_P pins. But each pair of pins can’t control a full ethernet port? Normally I would expect 2 pairs of TX+, TX- RX+ & RX- pins coming out of a phy to control a single ethernet port. So does this mean that 2 RMII ports need to be consumed to connect to a single RJ45 connector?? And does the single port version still drive both pairs of TRX0 and TRX1 pins meaning that a single RMII port can control a RJ45 connector?

[martinsmith]

Hi, thanks for the reply. Yes that makes sense and is the root of my problem, the TJA1102 is not suitable for my application and I'll find another IC

[diazmarin09]

Hello Martin,

I hope all is great with you.

Please note that the TJA1102 is a 100BT1 PHY which implies single twisted pair ethernet (UTP).

Traditional ethernet would be 4 wire for 100Mb (100BTx). The TJA1102 has 2 channels of 100BT1.

I hope this information helps.

Regards,

David