[SI-LIST] Re: off-diagonal resistance and conductanceelements
- From: "Neeraj Pendse" <cnepsc@xxxxxxxxxxx>
- To: si-list@xxxxxxxxxxxxx
- Date: Wed, 19 Feb 2003 15:32:55 -0800
Patrick:
Thanks for the clarification on that, yes this can be confusing. When I
said "self capacitance", I meant capacitance of conductor to ground
only. Even that capacitance will change if neighboring conductors are
deleted or changed - because fringing electric fields are changed.
Regarding self inductance, even if LOOP inductance is under
consideration, nothing matters as much as the relative location of the
ground path.
Anshuli:
If you are looking at an output from a EM calculator, then you should
ascertain with the technical documentation what is the definition of ALL
elements ... different simulators do this differently as Ray and others
have been pointing out.
"Zabinski, Patrick J." wrote:
>
> > With C, if the on-diagonal elements are SELF (not BULK), then the
> > on-diagonal element will change if the coupling conductors
> > were removed
> > while not disturbing the ground reference.
> >
>
> Please correct me if I'm wrong, but...
>
> Specific to the "C" matrix, several EM tools do not
> output a "capacitance" matrix. Instead, they output
> an "electrostatic induction" matrix (let's call it
> the "B" matrix), and it's quite common/easy to get
> them confused.
>
> Where C11 is considered to be the self capacitance of
> a trace (i.e., capacitance of the trace to the ground
> plane), B11 is the capacitance of the trace to all
> other elements (i.e., planes, traces, etc.) assuming
> they were all at ground potential.
>
> Where C12 is the mutual capacitance between Trace 1
> and Trace 2, B11 is the negative of that.
>
> A simple translation is necessary between the two:
>
> C11 = B11 + B12 + B13 + ...
> C12 = -B12
> C13 = -B13
> .
> .
> .
>
> Pat
--
National Semiconductor Corporation
2900 Semiconductor Drive, M/S 19-100
Santa Clara, California 95051
http://www.national.com/, NYSE: NSM
------------------------------------------------------------------
To unsubscribe from si-list:
si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field
or to administer your membership from a web page, go to:
//www.freelists.org/webpage/si-list
For help:
si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field
List archives are viewable at:
//www.freelists.org/archives/si-list
or at our remote archives:
http://groups.yahoo.com/group/si-list/messages
Old (prior to June 6, 2001) list archives are viewable at:
http://www.qsl.net/wb6tpu
Other related posts:
