Bruce Griffiths wrote: > An oscillator can be injection locked to at frequency that is a rational > number (M/N where M, N are integers ) multiplier of the injection frequency. > Thus, in principle, a 32768Hz oscillator can be injection locked > directly to a 10MHz signal (32768Hz = (256/78125)*10MHz) without > requiring any external dividers or multipliers. > In practice this will only be practical with a 32768Hz crystal > oscillator whose frequency determining crystal is tuned sufficiently > closely to 32768Hz. > Note this is not quite the same as tuning the free running oscillator > frequency. > The sensitivity to the injected signal can be optimised if the 32768Hz > oscillator is suitably designed. > > The 32768Hz injection locked oscillator output can be used to injection > lock another 32768Hz crystal oscillator whose design cannot be optimised > for direct injection locking to a 10MHz signal. > > Bruce > > The major problem with this approach is the extremely small (<<1ppm) locking range achievable. Thus it isnt likely to be practical with standard 32768Hz crystals, as even a relatively small temperature change will perturb the tuning sufficiently to make locking to the desired frequency impossible.
Bruce _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.