pablo alvarez wrote: > Hi, > > I have been looking at several Dual Mixer Time Difference designs. As > far as I know the basic architecture is based on generating a tone > with an small frequency offset respect to the nominal clocks > frequency, analogue mixing of the clocks, low pass filtering, then a > slow zero crossing detector and finally a time interval counter or > time stamp unit. > > I have this naïf question: would not it be better and simpler to use > directly an ECL D flip-flop as a mixer instead of an analogue one? I > suppose analogue mixers are preferred because they provide with a > better "differential tempco", but using ECL logic can provide also > with a good tempco. > > What is your experience? > > > Cheers > > Pablo > > Pablo
Flipflop mixers tend to produce glitches at the beat frequency transitions. A digital PFD in a PLL doesnt produce a beat frequency output when locked so such glitches arent a problem, Bruce _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
