PCIe clock distribution, 1:4 fanout, 400 MHz ceiling
The 9DB403DGLF is a PLL-based PCI Express (PCIe) clock buffer from Renesas, designed to take a single HCSL reference clock and distribute it to four output copies. The PLL cleans up jitter from the incoming clock, making it suitable for the 100 MHz reference tree in a PCIe root complex to downstream slot endpoints. Outputs are configurable as HCSL or LVDS, giving the layout engineer flexibility to route differential pairs to devices that prefer one standard over the other. The 400 MHz maximum frequency covers PCIe Gen1 through Gen4 base rates (100–400 MHz) with headroom. Supply voltage is 3.135–3.465 V — a tight 3.3 V ±5 % window. The board rail feeding this part must be a regulated supply, not a raw buck output, to stay inside the operating range across load and temperature.
Housed in a 28-TSSOP package with a 4.40 mm body width (0.173"), the 9DB403DGLF mounts on the surface of a standard PCB. The 0.65 mm pin pitch is routable on a 4-layer board without microvias; the differential input and output pairs should be length-matched and impedance-controlled to 100 Ω differential. This part fits enterprise server, storage, and networking gear that lives in a climate-controlled environment.