400 MHz HCSL fanout buffer for server clock trees
The Renesas 9ZXL1231EKILF is a 1:12 fanout clock buffer with an integrated PLL, designed to distribute HCSL reference clocks for Intel QPI and PCI Express (PCIe) interfaces. It accepts a single-ended or differential clock input and delivers twelve HCSL outputs at up to 400 MHz, making it a fit for server, storage, and datacom motherboards that need to fan out a clean reference to multiple endpoints — CPU, PCH, PCIe switches, and retimers.
Supply and temperature — what they mean for deployment
Supply range is 3.135 V to 3.465 V. Operating temperature is -40°C to 85°C.
1:12 fanout — sizing the clock distribution
With a 1:12 input-to-output ratio, this buffer replaces multiple smaller fanout parts or a clock-tree daisy chain. Twelve HCSL outputs can feed, for example, a dual-socket server's QPI links plus several PCIe root ports from a single device. The differential input and output (Yes/Yes) means it accepts and regenerates differential signals without single-ended conversion, preserving signal integrity across the board.
Lifecycle and compliance
The 9ZXL1231EKILF is listed as Active with ROHS3 compliance. The RoHS3 status means it meets the latest EU restriction levels for lead and other substances — no exemption paperwork needed for standard commercial or industrial products.
