What this part is — and the selection trap it avoids
The Infineon (Cypress) CY2304NZZXC-1T is a zero-delay clock buffer designed specifically for PCI Express (PCIe) reference clock distribution. It takes one LVCMOS or LVTTL input and fans it out to four LVCMOS outputs, with a maximum operating frequency of 140 MHz. The part has no internal PLL — it is a buffer, not a synthesizer — so the output clock tracks the input frequency and phase exactly, within the device's propagation delay. This matters because a common selection mistake is grabbing a general-purpose PLL-based fanout buffer for a PCIe clock tree, which adds jitter and can violate the PCIe reference clock specification. The CY2304NZZXC-1T avoids that: it is a clean, low-additive-jitter buffer purpose-built for the PCIe reference clock lane.
Supply and temperature — the commercial-grade reality
Operating from a 3 V to 3.6 V supply, this part is a 3.3 V nominal device — the standard PCIe reference clock rail. The operating temperature range is 0°C to 70°C, which is commercial grade. That means it is intended for office-environment equipment, not industrial or automotive applications. If your PCIe clock distribution needs to survive -40°C or +85°C, this is not the part; look at the industrial-temperature variant in the same family.
Package and footprint — what the 8-TSSOP means for the board
Housed in an 8-TSSOP package (4.40 mm width, 0.173" body width), this is a surface-mount part. The 8-pin TSSOP is a common footprint, and the supplier device package is also listed as 8-TSSOP, so there is no ambiguity about the land pattern. The part is available in Tape & Reel or Cut Tape, which covers both production reels and prototype quantities. No exposed thermal pad here — the 8-TSSOP dissipates through the leads and the board copper, so for high-frequency PCIe clock distribution at 140 MHz, the power dissipation is low enough that thermal management is not a concern.
Lifecycle and compliance — active, no obsolescence worry
There is no NRND or EOL flag on this part. It is also ROHS3 compliant, so it meets the latest EU RoHS exemption-free requirements. For a BOM line that needs a stable, long-life PCIe clock buffer, this part is not a sourcing risk.