PCIe clock distribution in an 8-pin TSSOP
The CY2304NZZXC-1 is a 1:4 zero-delay clock buffer from Infineon (formerly Cypress) designed specifically for PCI Express (PCIe) reference clock distribution. It accepts a single LVCMOS or LVTTL input and delivers four LVCMOS outputs at up to 140 MHz, with no PLL on chip — meaning it's a straight-through fanout buffer, not a jitter cleaner or frequency synthesizer.
140 MHz ceiling — what it means for PCIe generation fit
The 140 MHz maximum output frequency aligns with PCIe Gen 1 and Gen 2 reference clock requirements (100 MHz nominal, spread-spectrum capable). For Gen 3 and Gen 4, the reference clock typically runs at 100 MHz as well, but the jitter and phase-noise specs tighten considerably — this buffer has no PLL to clean up incoming jitter, so the upstream clock source quality determines whether the system meets the Gen 3/4 jitter budget. If your design targets Gen 1 or Gen 2, this part is a clean fit; for Gen 3 or later, verify the total jitter contribution against the PCIe base spec with your specific reference oscillator.
Single-ended I/O only — no differential support
Both the input and output are single-ended (LVCMOS/LVTTL in, LVCMOS out), with no differential signaling on either side. This means the CY2304NZZXC-1 cannot directly buffer a differential HCSL or LVDS PCIe clock — it expects a single-ended reference. If your clock source is differential, you will need a differential-to-single-ended converter ahead of this buffer, or choose a part with differential I/O. For systems already running a single-ended 100 MHz reference from a crystal oscillator or clock generator, this is a straightforward drop-in.
For desktop PCs, servers in climate-controlled data centers, or telecom equipment in conditioned bays, the commercial range is adequate.
Supply rail and package
Operates from a single 3.3 V supply (3 V to 3.6 V range), which is the standard PCIe reference clock voltage. The 8-TSSOP package with 0.173" body width and 4.40 mm width is a common footprint; the supplier device package is also 8-TSSOP. Surface-mount only, no through-hole option. ROHS3 compliant per the lifecycle record.