The Si5351 family is a configurable I2C clock generator designed to drive crystals, crystal oscillators, VCXOs, PLLs and fanout buffers. It supports up to 8 outputs with noninteger frequencies up to 160 MHz per output using a PLL/VCXO MultiSynth architecture with a fractional divider. Si5351A and Si5351B variants - Si5351A uses an internal oscillator to generate up to 8 running clocks, eliminating the need for external crystals. - Si5351B adds an internal VCXO and accommodates driving or locking to external pull crystals, offering a wider tuning range and flexible operation. - Si5351C synchronizes with an external reference clock (CLKIN) while still delivering up to 8 noninteger frequencies from 8 kHz to 160 MHz via I2C. Key benefits - Flexible, multioutput clocking with precise fractional frequencies up to 160 MHz per output. - Reduces BOM and board space by replacing multiple crystals and oscillators with a single device. - Simple I2C control enables easy integration with microcontrollers and FPGAs. - Compatible with crystals, VCXOs, PLLs and fanout buffers for wide design options. Use scenarios - Microcontroller or FPGA boards requiring multiple synchronized clocks with minimal components. - SDR or RF front-ends needing stable LO and sampling clocks from a single device. - Lab and test benches that require programmable reference clocks or external CLKIN synchronization. This device offers a compact, cost-effective solution for flexible, high-performance clocking in space-constrained designs.