AN 875: Intel® Stratix® 10 E-Tile PCB Design Guidelines

ID 683262
Date 3/12/2019
Public Cable Usage in PCB Design

The direct attached copper cable (DAC) is the most common cable usage in high-speed PCB link design. DAC is available in various cable lengths/sizes for different applications.

You must make sure the cable model boundary is clearly defined at both ends. In addition, you should check with the cable vendor if the cable model includes the cable wire termination and edge card (elements to consider in simulation).

A ~5 dB (at 14 GHz) host board, with most AWG-26 2 m, 3 m cables and 5 m cables and with careful transmit and receive equalization tuning, can support 56G PAM4. The E-tile PAM4 mode can support ~30 dB pad-to-pad loss in cable applications.

Figure 13. TX-RX Connection via Cable
Figure 14. Channel Eye Simulation of Different Cables (~5 dB RX and 5 dB TX PCB Trace Routing)