It is packaged using the Tape & Reel (TR) method since it is a clock IC. The number of uPs/uCs/PEripheral ICs contained in this clock generator is CLOCK GENERATOR, PROCESSOR SPECIFIC.
SI5351A-B04251-GTR Features
SI5351A-B04251-GTR Applications
There are a lot of Silicon Labs SI5351A-B04251-GTR Clock Generators applications.