External Magnetic Routing Review

TCP/IP Chip W5500
1

Hi,

Could you please let me know if my routing is good, or how can I improve it?

I have to use M12 connector for Ethernet connection, can’t find any reference layout for it. Two big extra holes are for plastic inserts for mechanical support.

Trace thickness: 10 mil
Distance between traces in the same pair: 8 mil
Length:
TX+: 855.669
TX-: 812.868
RX+: 431.944
RX-: 417.408

image
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2

Hi!
Could you show me your whole schematic of W5500?

3

Hi Jaden,

Thank you for the reply. Here is the schematic
W5500.pdf (300.0 KB)

The screenshot is the part where four wires coming to the magnetic as shown in the pdf file.

The pinout of the connector is here:

900001136-5
900001136-5837×462 73.8 KB

4

Hi there!
I saw the schematic and have a few questions.
L1 (33uH) is a power inductor. I recommend using a bead to isolate 3V3D and 3V3A. Is there a reason why you used a power inductor?

And case of M12 connector, you can design with any connector, but we can only guarantee optimal performance when using RJ45 jacks and cannot provide technical support otherwise.

5

Also I recommend connecting the Link (pin 25) and ACT (pin 27) of the w5500 for debugging and status checks.

6

Hi Jaden,

I will change L1 to a ferrite bead, and connect LEDs to pin 25 and pin 27.

I am facing a difficulty in routing from the magnetic to W5500. The TX pair is crossing the RX pair. It is recommended not to use vias for differential pairs, so I run TX under the magnetic; but now the two TX traces in the TX pair cross and I cannot connect the other trace to R8. Please see attached screenshot.

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Capture1346×890 27.2 KB

7

If the issue is not solved through component replacement, route with minimal use of via and shield the via to GND.