What this clock buffer does that a generic fanout can't
The Renesas 8535AGI-31LF is a 2:4 fanout buffer and multiplexer that takes single-ended inputs — LVCMOS, LVTTL, or a crystal — and delivers LVPECL outputs at up to 266 MHz. That input-to-output conversion is the key differentiator: most clock buffers either pass through differential or single-ended on both sides. Here, the single-ended-to-differential translation happens on-chip, saving an external translator and the associated PCB area and skew. It lives in a 20-TSSOP package, runs from a 3.135V to 3.465V rail, and is rated across the industrial temperature range of -40°C to 85°C.
The 266 MHz ceiling — where it fits and where it doesn't
The 266 MHz maximum frequency sets a clear boundary. This part is sized for PCIe Gen 1 reference clocks, Gigabit Ethernet, FPGA transceiver reference clocks at 125-156.25 MHz, and general-purpose system clock distribution at those rates. It will not retime a 312.5 MHz SerDes reference or a 400 MHz DDR5 clock — those need a higher-speed fanout like the 8SLVP1104 family that runs to 2 GHz. For the 266 MHz and below zone, the 8535AGI-31LF is a clean fit with margin on the edge rates.
Active and available — no LTB clock ticking
For a production clock tree that needs to ship for the next several years, this part does not introduce obsolescence risk.