PCI Express* (PCIe*) 4.0 Retimer Supplemental Features and Standard BGA Footprint
Overview
PCI Express* Gen4 capable retimers extend the channel reach on a platform to beyond what is possible otherwise.
With PCI Express Gen4 (16 GT/s), data rate has increased by 2x compared to previous generation (8 GT/s), resulting in shorter channel reach. Common use cases include channels expanding over system boards, backplanes, cables, risers, and add-in cards. Such long
channels can have loss that far exceeds the spec loss target of -28 dB at 8 GHz. Retimer is now part of PCI Express 4.0 base specification. PCI-SIG is expected to implement compliance program for testing retimers.
It is expected that significant number of platforms using PCI Express Gen4 will require retimers. Multiple sources of retimers will make adoption of PCIe 4.0 technology easier. Common footprint simplifies the platform design process. Pinout is optimized for 16 GT/s signal integrity and thermal challenges.