[time-nuts] Fast frequency counting question

Bruce Griffiths bruce.griffiths at xtra.co.nz
Sun May 4 17:30:17 EDT 2008

Murray Greenman wrote:
> Magnus,
> Thanks for your reply. Yes, I believe Leon has 30dB gain post mixer. He
> is using an FSS 1000E as his mixer. So, we don't think the problem is
> slew-rate limiting. Your suggestions for checking the performance with
> changes in level is a good one.
> This is an area of counting I've not considered before. We are working
> with the chip manufacturers, and they report the problem, which we would
> like to replicate. Personally I can't see it as an issue, but it has
> been raised, and we would like to understand how to measure it. The chip
> manufacturer has a high-speed A-D system and some method (unknown to us)
> for post-processing the data.
> I've suggested that Leon reply to you directly, as he has a better grip
> on what the problem and requirement is. I understand that the problem is
> relayed to warm-start TTFF performance in a GPS application.
>  Regards,
> Murray Greenman

Just adding a post mixer amplifier of unspecified bandwidth isnt the 
optimum way of amplifying the slope of a signal.
Using a cascade of stages with the gain and bandwidth increasing for 
each successive stage will produce an amplified signal with less jitter 
than just using a single gain stage.


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