Re: Connector spec swathing

From: fred <fred@apsimtech.com>
Date: Fri Jun 16 2000 - 03:58:58 PDT

You are confusing modeling and simulation. I'm not suggesting that you model the
full connector if its large. Rather, if you model only a portion then I prefer that
you
tell me that and give me that answer rather than bogus something. If you feel that
the
connector is repetative then put together the model such that I get a full matrix
type
or sparse matrix. This means I should have representative coupling between any
two or three pins as you may feel necessary. But I need the full model.
Verification
of the model is entirely a different animal and I cannot see how the swat helps
with
that process at all.

IF you give me the full model I may not attempt to simulate the whole thing. You are

only giving me information. Its up to me to use that wisely. For example if I choose

to simulate through connector pin number 5, I as a user may wish to consider only
coupling to pin 7 and pin 3. I can make that decision during simulation coupling
setup. The important thing is that I can get decent accurate data for the pins I
wish
to consider during simulation. If you give me the full model I will then PICK the
data I wish to simulate from the full data you gave me. However giving me a swat
ensures that for some pins I will lose some coupling. It also ensures confusion and

abiguity.

Please note that the swat does not help your modeling. It's only a way to present
the
data. So the issue of modeling the full connector versus giving me a full matrix is
a
seperate one. We're talking about how to present the data not field solver
algorithms.

Best Regards,

apanella@molex.com wrote:

> Fred,
>
> I am sure that if you have this question, so do others... as such I have
> prepared a fairly lengthy reply.
>
> The "basic" answer to the question is...
>
> Find a FIELD simulator that can generate a 100 pin connector model from a
> connector with a general current path length of around 2.5cm.
>
> Make sure it is a true 3D simulator.
>
> OK... now find one that can do such using less than 8GB of RAM and 4 xxxx GHz.
> processors
> - This is pretty much what one might call a high end PC/Workstation. Maybe
> even not "typical" hardware.
>
> OK... Using what has been found above... have the problem solve in the FIELD
> simulator in less than a week. (BTW, a week is solve time, it does not include
> reports, empirical confirmation, or support documentation)
>
> OK... now put that full matrix model that is generated into a circuit
> simulator.... Setup the rest of the problem.... go away for the weekend...
> comeback Monday.... still not done... Comeback Wednesday... Ooopps found out
> that a termination resistor was misplaced... restart the simulation.
>
> The point is... connector companies would be perfectly happy with smaller
> models...
>
> But from what I have been told my customers which are the same as many SI
> simulators NEED to be able to model 50, 100, 200, 500, 1000, 5000 pins... (Yes,
> these are all real connector sizes today).
>
> As a work around for this problem.... we suggest the preverbal "critical net
> analysis". Which will still take 8 hours to solve using something in the order
> of a 40 pin connector model.
>
> Also, I as a connector manufacture make parts with different circuit sizes...
> sometime from 10 to 1000 in 10 pin increments... OK... there we have 100
> models... Lets say we just go up to 100 pins... that is 10 models... at 3 days
> AVERAGE per model (smaller models take less time)... that means one month of
> FIELD SIMULATION time... and we STILL can not support any thing over 100 pins.
>
> Not to mention that connector companies have about 40,000 different product
> lines.. lets say conservatively that only 1% of the 40,000 require models...
> That's 400.... a conservative estimate would be that there are 10 circuit sizes
> for each of those 400 connectors... as such 4,000 different models. OF EACH
> Type. There are three basic types Single Line models, MultiLine Models, and
> Cascaded Models... then there are TWO VERSIONS of each type... distributed and
> lumped... grand total 24,000 SPECIFIC models.
>
> But wait, Now model makers and simulators also have to database and revision
> control the models.
>
> Point being... an auto swath will give end uses access to more models with more
> pin options than they ever had before (to answer the customers requests). And
> GREATLY reduce the redundancies such that the 24,000 models above can be done in
> 1 model per connector family.. or 400 files.
>
> _gus: 630-527-4617
>
> ____________________Reply Separator____________________
> Subject: Re: Connector spec swathing
> Author: fred <fred@apsimtech.com>
> Date: 6/15/00 1:33 AM
>
> I know the connector specification committee has spent much time and effort in
> comming up with the specification. However the current swat matrix approach
> seems overly complicated and technically less than desirable. Why not give the
>
> full matrix and let the simulation SI tool decide which part of the matrix to
> choose
> for simulation based on what pin and coupling is desired. We (simulation
> vendors)
> only need the data. We can decide how and when to use what. What we need is
> the committee to do is identify the connector pins to the matrix diagonal
> entrys. If
> the connector is very large in terms of number of pins then whether one gets a
> full
> or sparse matrix will depend on the field solver capabilities. This is not
> intended to
> be critical of the committee which has worked long and hard to come up with a
> spec
> in the first place while hence keeping everybody happy.
>
> Best Regards,
>
> Kellee Crisafulli wrote:
>
> > Hi Chris,<SNIP>
Received on Fri Jun 16 02:53:43 2000

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