Tool/software:
Is there an analog frequency comparator, which is similar to the phase comparators, for two sine waves at ~ 200 kHz?
It's hard to answer this question precisely, because it's not clear what the comparator output should be. There are probably ways to do this, though as far as I know they would not be straightforward with TI devices.
I think the most straightforward solution is to attach two voltage-to-frequency converters (such as VFC320) to your inputs, then directly compare the difference in voltage at the output of the VFCs. However, this is sort of a niche solution, and these devices are both old and very expensive for what they do.
Edit to add: The repeated use of "voltage-to-frequency" might look like a typo, but I really do mean voltage-to-frequency converters - a few can be configured as frequency-to-voltage mode.
You might also consider a downconverting mixer with the two inputs fed to RF and LO, which would yield the difference in output frequency directly on the IF port - this may be useful as-is depending on your application; and if the magnitude of the difference of the two sine waves is small, a much less expensive voltage-to-frequency converter could also be used on just the IF signal.
Pure analog solutions for 200kHz sine wave frequency comparison seem to me to be a curiosity, when there's dozens of microcontrollers with built-in ADCs that could perform this comparison to a reasonable degree of accuracy for a fraction of the hardware cost (and likely a fraction of the development time - the old analog components are often tricky or temperamental in surprising ways). I think you'd practically always be better served just going the microcontroller route if you have the option.
