HATs and other add-ons • Custom PCIe cable design for PI5

I am currently in the process of designing a new HAT and a compatible cable for the system. While reviewing options with PCB manufacturers, I encountered an issue with achieving the required 90Ω impedance for PCIe signals. Specifically, I found that 2-layer PCBs typically use a 25μm dielectric material, which makes it impossible to achieve the 90Ω impedance target. Although a 4-layer PCB could potentially meet the requirement, it comes at a significantly higher cost.

Could you share insights on how you successfully achieved the 90Ω impedance in your system? Any guidance or recommendations would be greatly appreciated.

Thank you in advance for your assistance!

Statistics: Posted by mezarkabul — Mon Feb 10, 2025 2:10 pm

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