[time-nuts] 5 MHZ PIC PPS Divider?

Jim Lux james.p.lux at jpl.nasa.gov
Sat Apr 12 11:57:56 EDT 2008


Quoting John Ackermann N8UR <jra at febo.com>, on Sat 12 Apr 2008  
07:44:06 AM PDT:
>
> * I realize that I'll also be limited by counter resolution.
> ----

Unless you use some sort of "time to digital" converter.  There's some  
ASICs out there that do this, and I've seen CPLDs programmed to do it.  
  The new fancy oscilloscopes from,e.g., Tektronix have this so that  
you can measure jitter to finer resolution than the 20Gs/s sample rate.

Seems one could also do a similar Time-to-Digital thing by using the  
old vernier counter scheme.. take your 5MHz and create a slightly  
offset version (4.9,5.1, or 5.01, etc.) by dividing and mixing and  
hook it up to a second counter.

Jim Lux



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