From: "Tim"
Newsgroups: sci.electronics.design,sci.electronics.components,sci.electronics.equipment,sci.electronics.repair
Subject: Re: AN: New Logic Analyzer, 500MHz, $166
Date: Tue, 19 Nov 2002 02:00:36 -0000
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Well, the analyzer runs at 500MHz, takes samples at 500MSample/s,
and should be used with signals up to around 100MHz. And even with
slower signals some minimal level of thought must be given to the
hookup arrangements.
Of course we have yet to address the key parameter of millions of
samples per second per cubic inch per watt :-)
Jim wrote
> Tim wrote
> >
> > The convention is to quote the absolute maximum speed which
> > cannot be exceeded under any circumstances :-) Since the
> > maximum sampling speed is 500MHz, it becomes a 500MHz logic
> > analyzer, but I can see the argument for making it a
> > "500MSample/s logic analyzer."
> >
> Hmmmm.... I thought the nyquist theory requires a MINIMUM of two sample
> points which makes it a 250MHz Logic analyzer at the best of times.
>
> And, since logic pulses are often not 50% duty cycle, one has to allow
> for the minimum pulse width when specifying the guaranteed data rate.
>
> So, this analyzer is more reasonably something like a 100MHz logic
> analyzer which allows for less than 50% duty cycles and so on.
>
> Marketing specs for a lot of companies are usually pretty far from the
> real world performance....