Review on 🕒 Adafruit Si5351A Clock Generator Breakout Board - Versatile Frequency Range from 8KHz to 160MHz [ADA2045] by Mark Lowery

The hardware setup for this module is done with just a few cables, and the "Clock Assistant" from Silicon Labs helps to set up up to 3 clocks and (from version 6.5) even when generating a register configuration function in an independent platform 'C' header file. NV-RAM is used for Si5351A registers, so the clock starts running even after power cycling. There is no need to "turn on" it to use clock signals in projects, only when it is necessary to reconfigure the registers (which should extend the lifetime of the NV-RAM registers). If required, each clock can be (independently) configured for input impedance, phase shift, jitter rejection and output current/impedance. Without a doubt, this is a much better PLL source than a mere FPGA; also a bit cheaper. I haven't seen any Si5351B/C modules (very similar to "A" but with 8 clocks), so it's nice that this module only needs an I2C connection to set up, meaning any number to Running a project can be used. Oh, the output of this module is a square wave with a 50% duty cycle. The datasheet is easy to find online.