Part Number: AM3352
Other Parts Discussed in Thread: DP83869
I’m working on a custom board with the following components: AM3352 CPU, KSZ9031 PHY, and S558-5500-68 (discrete, not a module) for PoE and LAN transformers.
Currently, I’m encountering 1 Gbps link detection issues. I’m reviewing the hardware to determine whether the issue originates from the CPU or PHY side.
I’m also unclear on the recommended termination topology. In the reference designs:
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Some connect CT1–CT4 to 22 nF, then to 75 ohm, followed by 1 nF to chassis( Bob smith).
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Others connect first to 75 ohm, then to 22 nF.
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Some omit the 22 nF entirely.
On the PHY side, the approaches also vary:
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Some tie CT1–CT4 together and then connect to decoupling capacitors.
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Others connect each line to separate capacitors and then to ground.
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Some even include PHY-side termination. 75 and caps(Bob smith).
My current setup :
Sugested change:
KSZ9031 recom:
