The Si522xx is the industry's highest performance and lowest power PCI Express clock generator family for 1.5–1.8 V PCIe Gen1/2/3/4 and SRIS applications. The Si52212, Si52208, and Si52204 can source twelve, eight, and four 100 MHz PCIe differential clock outputs, respectively, plus one 25 MHz LVCMOS reference clock output. The Si52202 can source two 100 MHz PCIe clock outputs only. All differential clock outputs are compliant to PCIe Gen1/2/3/4 common clock and separate reference clock architectures specifications.

Individual hardware control pins and I2C controls for Output Enable, Spread
Spectrum Enable and Frequency Select
Triangular spread spectrum for EMI reduction, down spread 0.25% or 0.5%
Internal 100 Ω or 85 Ω line matching
Adjustable output slew rate
25 MHz crystal input or clock input
I2C support with readback capabilities