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Anik , 04-06-2024, 06:43 PM

I am trying to build a multifunctional board with wifi , ethernet, RS485 and some other functions. I need to help about how to improve EMC and EMI. I am researching on google and reading blogs. But I need a brief on it. How to select Ferrite bead. Please review the schematic.
Kind Regards,
Anik

QDrives , 04-06-2024, 08:32 PM

1) Did you already do EMC and EMI tests and if so, at what frequencies did it fail?
2) Which ferrite bead (L1 and L2)? Why do you need a ferrite bead?

Anik , 04-10-2024, 07:57 PM

https://docs.wiznet.io/Design-Guide/hardware_design_guide

I am using this guidelines for designing a ethernet layout. And What about the highlighted, Do I not use ferrite bead for separating AGND and DGND??

Anik , 04-10-2024, 07:58 PM

Anik , 04-10-2024, 07:59 PM

Anik , 04-10-2024, 08:07 PM

Also I can see there say avoid stubs, So where I am using TVS diode for protection, but how can I route this without stubs? On the guidline its also written to keep 25mm distance from the Chip to Rj45. For maintaining this distance creating lack of space. Also its restricted to pass trace under the ethernet wire RX TX. but i am using 4 layer. Can i pass wire under the RX TX trace through the bottom layer??

Anik , 04-10-2024, 08:09 PM

Please give me some guidelines about the how to route ethernet layout with improving on EMI and EMC

Mini , 04-11-2024, 01:00 PM

Whenever you place components you place them IN-LINE with the track not like star like topography. I think that's what they mean as well.

Anik , 04-11-2024, 08:54 PM

Done, but
This green area need analog GND, do I need to maintain this analog gnd area for each layer. Cause this is 4 layer PCB, second layer is digital GND plane zone

Anik , 04-11-2024, 09:19 PM

And can I pass trace from the bottom layer under this two differential wires?

Mini , 04-11-2024, 10:55 PM

What is your layer stackup? I normally use signal/power-gnd-gnd-signal/power or signal-gnd-power-signal. This way always gnd plane below and tracks made on outer layers, no worries about running some tracks under or over high speed signals.

Anik , 04-12-2024, 05:49 AM

Signal- GND-Power/signal-Signal

QDrives , 04-12-2024, 04:11 PM

You just have a 'single' Gnd plane. And with single, I mean Gnd net even if it is on multiple layers.

Anik , 04-12-2024, 04:15 PM

Actually My layer stack up is,
Signal/GND - GND- Power/signal/GND- signal/GND
Every layer has copper pour.
But only second layer is single GND solid plane.

Anik , 04-12-2024, 04:15 PM

On the power layer, there willbe very limited signal trace.

QDrives , 04-12-2024, 04:16 PM

"On the guidline its also written to keep 25mm distance from the Chip to Rj45" -- I see this: "Recommended signal length is less than 25mm", that means you cannot have them 25mm apart.

QDrives , 04-12-2024, 04:18 PM

Do you need a power layer? https://www.youtube.com/watch?v=kdCJxdR7L_I&pp=ygUacm9iZXJ0IGZlcmFuZWMgcG93ZXIgbGF5ZXI%3D