PCIe clock distribution with PLL cleaning
The Renesas (formerly IDT) 9DB803DGILFT is a 1:8 differential clock buffer with an integrated PLL, purpose-built for PCI Express reference clock trees. It accepts a single HCSL input and delivers eight HCSL outputs at up to 400 MHz, covering PCIe Gen1 through Gen4 and the 400 MHz baseline for Gen5. The PLL cleans incoming jitter and provides deterministic output-to-output skew, which matters when routing clocks to multiple slots or endpoints on a server or switch board. Operating from a 3.135 V to 3.465 V supply and rated from -40°C to 85°C, this buffer suits industrial-temperature networking gear, base stations, and outdoor telecom equipment — not just climate-controlled data centers. The 48-TSSOP package (0.240" body width) keeps the board footprint compact for dense layouts.
What the 400 MHz and 1:8 ratio mean for your BOM
The 400 MHz maximum output frequency covers the PCIe Gen4 reference clock rate (100 MHz multiplied) and the Gen5 baseline. If your design targets Gen5, this buffer meets the frequency requirement. The 1:8 fanout ratio means one input drives eight outputs — enough for a typical motherboard with multiple PCIe slots or a switch card with several downstream ports. The PLL also reduces additive jitter, which is critical for maintaining the tight phase-noise budget of high-speed serial links.
For a BOM line, this means no near-term obsolescence risk and normal availability through distribution.