Book Signal Integrity for PCB Designs available on net

 

Hello friends , I came across a book for Signal Integrity which is
available on internet. Check out

http://www.ezdia.com//Signal-Integrity-for-PCB-Designers/Content.do?id=1435

The complete book will be made available over a period of two weeks.

 


From the above:

---

Tom - I was reading this rise time and knee frequency stuff. It says that the
rise time is a significant thing and determines the highest frequency content.
Does it mean that if I have a 1 KHz square wave that has a rise time of 100
ps, it should be treated as a high frequency signal with spectral frequency of
or 3.5 GHz?

Bob - Ideally, yes, this 1 KHz signal should be treated as a 3.5 GHz signal at
least from some of the SI angle, e.g., EMI. But Tom tell me why will anyone
design a circuit with 1 KHz frequency with such a fast rise edge? Does it make
sense? A very fast rising edge makes sense only when you want to achieve high
data rate.

---

Seems like that needs a bit more qualification... more like, "while not too
many applications require super-fast edges but have low repetition rates,
sometimes this will occur..."

 

On Thu, 11 Mar 2010 10:51:27 -0800, "Joel Koltner"


3.5 GHz is the 3.5 millionth harmonic of 1 KHz. So the power spectral
density up there will be zilch.

But a fast edge can ring at any frequency, and that could, for
instance, mis-clock a flipflop. So just because a signal is 1 KHz
doesn't mean it's "low frequency" and safe to use in a digital system.

John

 

John Larkin a écrit :

content.

of

at

make

Let's push it a bit further...

350MHz is still 350Kth harmonic of 1kHz and there's still almost nothing
there. So we can safely ignore this part of the spectrum...

... and, once provided the signal fundamental frequency is low enough we
can design a rather band limited channel while still achieving fast rise
time.

Cute!


--
Thanks,
Fred.

 

Fred Bartoli wrote:

Even better. Since you have now determined that we no longer need the
range from 350MHz to 3.5GHz we could auction that off and issue revenue
anticipation bonds to plug some pressing holes in the budget. Since the
money will have been spent by the time the auction happens we could
already look at whether the 35kth harmonic is good enough so we can pay
the interest :-)

--
SCNR, Joerg

http://www.analogconsultants.com/

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