We'll probably do this in a cute little efinix FPGA (digitally, and not 4KV) which has a megabit of ram, so we can pull more bits out of the phase accumulator and have a lot more entries in the sine table, which will improve jitter at low frequencies.
We might even use a 14-bit DAC, if that helps much. The efinix RAM comes in slices 5 bits wide, so 14 takes no more than 12. Might explore 10 and see what happens.
Now I need a good way to measure peroid jitter, so I can play with options.
keywords LT Spice DDS clock frequency synthesizer phase accumulator jitter filter coffee yardwork sucks