Skip to main content
Log in
Renesas Electronics 9ZXL1231EKILF — Clock & Timing ICs

9ZXL1231EKILF Clock Buffer, 400 MHz HCSL, 1:12 Fanout

MPN9ZXL1231EKILF
End of Life

Renesas 9ZXL1231EKILF clock buffer, PLL Yes, Input Clock, Output HCSL, 1:12 fanout, 400 MHz max, 3.135V–3.465V supply, -40°C to 85°C, 64-VFQFPN (9x9), Surface Mount, Tray.

$6.81Ref. price · indicative, final on quote
Renesas Electronics 9ZXL1231EKILF datasheet (PDF)
Packaging64-VFQFN Exposed Pad
RoHSROHS3 Compliant
Independent supplier — new & surplus stockAuthenticity-screened · ESD-safe packingListing updated Aug 2026

Specifications

9ZXL1231EKILF specifications
ParameterValue
MountingSurface Mount
Voltage3.135V ~ 3.465V
Frequency400MHz
Operating temperature-40°C ~ 85°C (TA)
PLLYes
InputClock
OutputHCSL
PackageTray
Main purposeIntel QPI, PCI Express (PCIe)
Case64-VFQFN Exposed Pad
Number of circuits1
Ratio - Input:Output1:12
Differential - Input:OutputYes/Yes

Product details

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

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.

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.

Frequently asked questions

Is 9ZXL1231EKILF compatible with Intel QPI?

Yes, the 9ZXL1231EKILF is designed for Intel QPI and PCI Express (PCIe) clock distribution. Its HCSL outputs and 400 MHz maximum frequency cover QPI link rates and PCIe Gen1 through Gen3 reference clock requirements.

What is the difference between 9ZXL1231EKILF and 9ZXL1231EKI?

The suffix 'LF' indicates RoHS3 compliance (lead-free). The 'EKI' variant without 'LF' may not carry the same RoHS3 rating. Electrically and functionally the parts are identical — the difference is only in environmental compliance documentation.

Can 9ZXL1231EKILF be used for PCIe Gen3?

Yes. PCIe Gen3 requires a 100 MHz reference clock with tight jitter limits, and the 400 MHz maximum frequency of this buffer provides ample headroom. The HCSL output standard matches the PCIe reference clock specification, and the integrated PLL cleans up incoming clock jitter before distribution.