The other day I was visiting my customer in China. I actually visited a few customers. Actually, you do get a lot more information from the customer when you talk to them face to face instead of email. I guess some customers won't tell you their problem until you meet them in person.
Anyway, this customer I visited has designed their own board and PCB. Upon looking at their PCB, I noticed that the MAG JACK's ground is not isolated. This might cause EMI and EMC interference. It is a better pratice to seperate the ground planes especially the RJ45 is very likely to sustain noise from the Ethernet cable. In this article, we will go through a few design considerations for the PCB design.
1) Isolate the ground plane of RJ45 from the main ground plane. Connect these two ground plane by ferrite bead. Be sure there is no ground plane under the isolated area
2) Place circuitry A and B as highlighted in the picture as close to the magnetic as close as possible
3) The crystal should not be placed close to I/O port, edge of PCB board or the magnetic devices
I hope this helps you design your PCB board :) Thanks!
Great article. The way you explained it is really awesome and makes every one to read till the end. keep posting..pcb assembly services
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