Planes Below LAN8742 for Differential Pairs?

[@petersage5157]

I'm looking forward to seeing some videos discussing the use of magnetics with PCB mounted connectors. As an audio analog guy, I think they could be useful in bandpass filtering.

[@damny0utoobe]

Thanks for the video, feedback:please lower music volume on the intro when you're talking.

[@AltiumAcademy]

Noted!

[@dmytromykhailiuta]

Can I change places _P and _N in pairs of RX and TX for more correct design signals? It works, I have already done it. But I wanted to get official approval :) I use LAN8720A. The need for this arises when the transformer and the chip are mounted on different sides of PCB.

[@dawidmilcarek5573]

LAN8720A is supporting polarity correction and Auto MDI-X so you can swap RX/TX pair and P/N signals as well. Signal polarity is important only for 10BASE-T transmision, 100M and 1G is not using signal polarity.

[@dmytromykhailiuta]

@@dawidmilcarek5573 , Thanks for the answer. I was guided by the description of the chip. Here is the quote: ( HP Auto-MDIX facilitates the use of CAT-3 (10BASE-T) or CAT-5 (100BASE-T) media UTP interconnect cable without consideration of interface wiring scheme. If a user plugs in either a direct connect LAN cable, or a cross-over patch cable, as shown in Figure 3.4, the device’s Auto-MDIX transceiver is capable of configuring the TXP/TXN and RXP/RXN pins for correct transceiver operation. The internal logic of the device detects the TX and RX pins of the connecting device. Since the RX and TX line pairs are interchangeable, special PCB design considerations are needed to accommodate the symmetrical magnetics and termination of an Auto-MDIX design. ). It is not indicated that polarity can be reversed, it is not indicated that there are restrictions with 10BASE-T. But it works. 10BASE-T did not check. Thanks.