Robert -

Yes, a couple of responses have suggested that I point out the RF
bypassing thing.  Here's a revised paragraph:

=======================================

If this were the only significant source of inductance, then using a
50% thinner dielectric would give a 41% higher self-resonance
frequency, while simultaneously doubling the capacitance. The makers
of SM low-ESL capacitors are utilizing this principle by shepherding
currents in their parts to achieve at least some degree of field
cancellation, at higher cost associated with the more complex
interior structure that is required. I should point out that a
capacitor will still perform some decoupling duties above this
trasition since its impedance will still be very low, enabling high-
frequency noise to be drained to ground.  This filter vs. power
supply aspects of decoupling capacitors will be the topic of a future
column.

======================================

When I write that one I'll for sure get you EE's to review it.  You
don't want a ChemE guessing at this stuff!

- Rick

******************************************************
Dr. Richard Ulrich
Professor
Dept. of Chemical Engineering
3202 Bell Center
Univ. of Arkansas
Fayetteville, AR   72701

[log in to unmask]
(479) 575-5645
******************************************************

On May 4, 2005, at 12:41 PM, Croswell Robert-CRC060 wrote:

> Wow, Percy, spoken like an EE!
>
> Rick, the other situation (that you probably will discuss in a
> subsequent column) is RF bypassing.  The problems are similar, but
> the issue is more of parasitic resistance rather than inductance
> (minimal ESR).  This gives a minimal impedance to ground near
> resonance.  Will you be kicking this topic around?
>
> Robert
>
> Robert T. Croswell, Ph.D.
> Motorola Labs
> (847) 538-5397
> (630) 400-6940 (mobile/SMS)
>
>
> -----Original Message-----
> From: EmbeddedNet [mailto:[log in to unmask]] On Behalf Of Percy
> Chinoy
> Sent: Wednesday, May 04, 2005 12:17 PM
> To: [log in to unmask]
> Subject: Re: [EM] CircuiTree Column Draft
>
>
> Hi Rick,
>
> The article is nicely written and easy to understand.  Catchy title!
> When you talk about the effect on inductance from fields adding or
> cancelling due to currents being in same or opposite directions,
> you may
> want to specify that you are talking about magnetic fields.  Also a
> simple
> formula showing relationship of inductance and capacitance with
> self-resonant frequency may help people understand the increase or
> decrease in fr.
>
> regards
>
> Percy Chinoy
> Global Business Manager  |  Rohm and Haas Electronic Materials  |
> Circuit
> Board Technologies
> Tel: (508) 787-4697  |  Mobile: (781) 363-1129
>
>
>
>
> Richard Ulrich <[log in to unmask]>
> Sent by: EmbeddedNet <[log in to unmask]>
> 05/04/2005 11:50 AM
> Please respond to
> D-50 Embedded Devices Committee Forum <[log in to unmask]>; Please
> respond to
> Richard Ulrich <[log in to unmask]>
>
>
> To
> [log in to unmask]
> cc
>
> Subject
> [EM] CircuiTree Column Draft
>
>
>
>
>
>
>
> Here?s a draft of my upcoming column for CircuiTree magazine,
> probably to run in July. I like to show these around to my colleagues
> in the business to make sure they are as accurate as possible, so
> please look it over in the next few days and let me know if there is
> anything you think needs changing.
>
> Thanks,
> Rick
>
> ?
>
> ******************************************************
> Dr. Richard Ulrich
> Professor
> Dept. of Chemical Engineering
> 3202 Bell Center
> Univ. of Arkansas
> Fayetteville, AR   72701
>
> [log in to unmask]
> (479) 575-5645
> ******************************************************
>
>
> [attachment "Ulrich Column 10.pdf" deleted by Percy
> Chinoy/NAmerica/Shipley]
>