What this clock generator does on the board
The Cypress CY22393FXI is a programmable clock generator and fanout distribution IC that takes a single LVTTL or crystal input and delivers six CMOS outputs. Its PLL with bypass lets you choose between a clean, jitter-free crystal-derived clock or a multiplied PLL output, giving the system designer flexibility to clock different speed domains from one reference. The 166 MHz maximum output frequency covers most microcontroller, FPGA, and memory bus clocking needs without pushing into the more expensive high-frequency PLL territory. The 1:6 input-to-output ratio means a single oscillator can drive six loads, saving a clock buffer IC and its associated board space.
166 MHz ceiling — what it buys you on the bus
At 166 MHz, the CY22393FXI can clock a 100 MHz or 133 MHz bus with margin, or drive a 166 MHz DDR memory interface directly. The PLL bypass mode is useful when you need a clean, unmultiplied crystal frequency for a low-jitter reference — say, for an audio codec or an ADC sample clock — while the PLL outputs serve the rest of the board. The trade-off: differential outputs (LVPECL, LVDS) are not available, so this part is limited to single-ended CMOS clock distribution.
Industrial temperature grade — where it lives
The 3.135 V to 3.465 V supply tolerance means it runs cleanly off a standard 3.3 V rail with ±5% regulation, which is the norm for most digital logic and FPGA boards.
The supply decoupling should follow the datasheet's recommended layout: a 0.1 µF ceramic close to each supply pin, with a bulk 10 µF tantalum or MLCC on the input rail.
For volume production or a BOM line that needs dual-sourcing resilience, the closest functional peer is the CY2305SXI-1HT — a fanout buffer and zero-delay buffer with a 1:5 I/O ratio and 133.33 MHz max frequency, also in a surface-mount package.