[ibis-macro] Re: Question at IBIS Summit
- From: "Muranyi, Arpad" <arpad.muranyi@xxxxxxxxx>
- To: "Bob Ross" <bob@xxxxxxxxxxxxx>
- Date: Tue, 20 Sep 2005 10:45:46 -0700
Bob,
I am not sure that I understand your explanation.
Either way, the problem with that is that the center
line (the DC component) goes up/down between the
strong and weak bits, introducing a common mode
component to the signal which is not very desirable...
Regarding the adder, you are making a good point,
I didn't think of it when I reviewed the presentation.
I really don't know why Todd put that there, but I
can imagine that it may work if you used a current
adder instead of voltage adder. I will have to
think about that some more...
Thanks,
Arpad
==================================================
-----Original Message-----
From: Bob Ross [mailto:bob@xxxxxxxxxxxxx]
Sent: Tuesday, September 20, 2005 10:39 AM
To: Muranyi, Arpad
Cc: Todd Westerhoff; Mirmak, Michael; bob@xxxxxxxxxxxxx;
ibis-macro@xxxxxxxxxxxxx
Subject: Question at IBIS Summit
Arpad:
You asked at the Summit meeting why the bottom side
pre-emphasis (de-emphasis) was less than the top side
in slide 8 of ross1.pdf for the SPICE simulation.
My (expanded) response was that the pulldown impedance
(of the Main) varied over the full range (1.8 V to .5 V),
and the lower impedance (as seen by the Boost) at the
lower end accounted for the reduced de-emphasis amplitude.
This is also seen later in all the IBIS simulations when
the buffer is constructed with [Driver Schedule] which
take into account all the load interactions.
The pre-emphasis template in Todd's presentation westerhoff.pdf
slide 8 show the connection through an Adder function. This
appears to remove any interactive load dependency. Is
this correct? If so, then we need a different method of
combination in the template to correctly mimic some real world
situations.
Bob
--
Bob Ross
Teraspeed Consulting Group LLC Teraspeed Labs
121 North River Drive 13610 SW Harness Lane
Narragansett, RI 02882 Beaverton, OR 97008
401-284-1827 503-430-1065
http://www.teraspeed.com 503-246-8048 Direct
bob@xxxxxxxxxxxxx
Teraspeed is a registered service mark of Teraspeed Consulting Group LLC
---------------------------------------------------------------------
IBIS Macro website: http://www.sisoft.com/ibis-macro
IBIS Macro archives: //www.freelists.org/archives/ibis-macro
To unsubscribe send an email:
To: ibis-macro-request@xxxxxxxxxxxxx
Subject: unsubscribe
Other related posts:
