Si5351 Programmable Clock Generators Skyworks Solutions Inc. Si5351 Programmable Clock Generators can be customized to generate up to eight independent non-integer-related frequencies. These clock ICs have eight CMOS clock outputs offered in a space-saving 4mmx4mm 20-QFN and 24-QSOP package or three clock outputs offered in a 10-MSOP package. Each output has an independent MultiSynth™ fractional divider that accepts a high-frequency reference from one of the devices' internal PLLs and accurately divides down the clock to generate unique, non-integer-related frequencies from 8kHz to 133MHz. Any combination of output frequencies can be generated by the device. All clocks are generated with 0ppm frequency synthesis error, enabling the replacement of XOs and PLL-based clocks while simplifying design and minimizing cost. As an added feature, the Si5351 features an integrated VCXO, which eliminates the need for pullable crystals.