CK505 PLL clock generator for Intel CPU / PCIe platforms
The 9LPRS525AGILF is a CK505-compatible PLL clock generator IC from Renesas, designed to provide the reference clocks for Intel CPU and PCI Express (PCIe) buses. It accepts a crystal input and delivers up to 19 differential clock outputs at frequencies up to 400 MHz, covering the reference-clock needs of PCIe Gen1/2/3 and Intel CPU host-bus interfaces. The single 3.135 V to 3.465 V supply and industrial temperature range (-40°C to 85°C) suit it for embedded motherboards, industrial PCs, and telecom line cards that need a clean, low-jitter clock tree from one fanout device.
19 clock outputs from one crystal — fanout planning
A 1:19 input-to-output ratio means a single 25 MHz or 27 MHz crystal can feed nineteen clock loads — CPU, PCH, PCIe slots, SATA, USB 3.x, LAN controllers — without external fanout buffers. The differential outputs (No/Yes) are HCSL-compatible for PCIe reference clocks; the single-ended outputs serve legacy peripherals. When laying out the board, note that all nineteen outputs share the same PLL core, so any output frequency change requires reprogramming the entire device — not per-output independent synthesis.
400 MHz ceiling — PCIe generation support
The 400 MHz maximum frequency covers the 100 MHz base reference for PCIe Gen1/2/3, plus the 133 MHz and 200 MHz clocks used by Intel CPU host interfaces and memory controller hubs. It does not natively generate the 25 MHz or 48 MHz USB/SATA reference — those are derived from the crystal input and internal dividers. For PCIe Gen4 (16 GT/s) the reference clock spec tightens jitter requirements; the 9LPRS525AGILF datasheet should be checked against the Gen4 clocking spec before committing a new design.
Active, ROHS3, industrial temp — no obsolescence risk
The -40°C to 85°C operating range is wider than the commercial 0°C to 70°C grade found on many CK505 parts, making this variant suitable for outdoor telecom, industrial motor drives, and automotive infotainment head units that see temperature cycling.