PT5081LRS

Overview

The PT5081LRS is a 8-Lane PCI Express (PCIe) Gen-5 protocol-aware low-latency Smart Retimer designed to integrate seamlessly between a Root Complex and End Points. It extends signal reach by >36 dB at 32 GT/s, enabling the use of lower-cost PCB materials and connectors while maintaining signal integrity. The device supports flexible link bifurcation configurations including 1x8, 2x4, and 4x2 links. It features integrated AC-coupling capacitors, an HCSL reference clock output, and advanced in-band and out-of-band diagnostics for fleet management. The component operates within a junction temperature range of -10 °C to 110 °C and is housed in a 354-pin Flip-Chip CSP package.

Feature Summary

• Protocol-non-disruptive low-latency architecture that significantly reduces latency through the retimer while remaining transparent to system software.
• Flexible link bifurcation capabilities supporting various end-point port configurations such as x8, x4, and x2 links.
• Integrated AC-coupling capacitors reduce solution size and improve signal integrity performance without requiring external components.
• Advanced diagnostics accessible via in-band receiver margining and out-of-band SMBus methods for large-scale server deployments.

Applications

• Server and high-performance PC motherboards
• PCIe riser and add-in cards
• NVMe JBOFs and GPU/deep-learning accelerators

Procurement Notes

Verify the specific ordering suffix 'S' against official Astera Labs documentation to confirm the packaging quantity and tape-and-reel specifications. Ensure compatibility with lead-free assembly reflow profiles consistent with IPC/JEDEC J-STD-020E standards. Confirm operating junction temperature requirements align with the specified -10 °C to 110 °C range for the target deployment environment.

Selection Notes

Select the PT5081LRS when an 8-lane PCIe Gen-5 or CXL connection requires signal regeneration over extended distances. This part is suitable for space-constrained designs due to its compact BGA footprint and integrated passive components. Consider this model for applications needing independent per-link diagnostics and automatic polarity correction without additional system software overhead.

Part Context

The PT5081LRS belongs to the PT5xxx family of Smart Retimers from Astera Labs, which are purpose-built for cloud-scale interconnects. It shares pin and register compatibility with other members of the portfolio, facilitating easy performance scaling between CXL and PCIe Gen-4/Gen-5 implementations. This family addresses signal integrity challenges inherent in high-speed data transmission for modern AI and server infrastructure.

Replacement Considerations

The PT5081LX serves as a compatible alternative within the same product family, offering identical electrical characteristics but supporting both CXL and PCIe Gen-5 protocols. Verify if CXL support is required for the specific application before substituting, as the PT5081LRS is primarily designated for PCIe Gen-5 operations.