200 MHz, 1:25 fanout — clock distribution for DDR DIMMs
The W255H is a low skew clock driver from Cypress, purpose-built for DDR and SDRAM DIMM modules. It takes a single clock input and fans it out to 25 outputs with minimal skew, running at up to 200 MHz. The part operates from dual supply rails — a 2.5V core and a 3.3V I/O — matching the voltage domains typical on DDR memory buses. It is packaged in a 48-lead SSOP (0.295" body width) for surface-mount assembly, and rated over the commercial temperature range of 0°C to 70°C.
Single-ended only — no differential support
Both the input and outputs are single-ended; the part does not accept or generate differential clock signals (no LVDS, LVPECL, or HCSL). If your DIMM interface expects a differential clock, this driver is not a fit. For single-ended TTL/CMOS-level clock trees up to 200 MHz and 25 loads, it covers that ground cleanly.
RoHS non-compliant — plan your exemption
The W255H is marked RoHS non-compliant. If your BOM requires full RoHS conformance, this part needs an exemption or a lead-free alternate. Verify your assembly house's policy on tin-lead finishes before committing the line.
Active production — no LTB risk
For new designs or ongoing production, this part is a safe lifecycle pick — no forced redesign horizon from obsolescence.