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From: Joe Gwinn <joegwinn@comcast.net>
Newsgroups: sci.electronics.design
Subject: Re: Interesting reading about spread-spectrum, also for on-board designs
Date: Mon, 24 Jun 2024 10:35:42 -0400
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On Sun, 16 Jun 2024 07:01:41 -0700, john larkin <jl@650pot.com> wrote:

>On Sun, 16 Jun 2024 05:26:35 GMT, Jan Panteltje <alien@comet.invalid>
>wrote:
>
>>On a sunny day (Sat, 15 Jun 2024 08:43:12 -0700) it happened john larkin
>><jl@650pot.com> wrote in <esar6jdro3r7ki70t17jsmpo48qkkg05na@4ax.com>:
>>
>>>On Sat, 15 Jun 2024 05:57:23 GMT, Jan Panteltje <alien@comet.invalid>
>>>wrote:
>>>
>>>>On a sunny day (Fri, 14 Jun 2024 07:55:14 -0700) it happened john larkin
>>>><jl@650pot.com> wrote in <45mo6jhcq8kisjmbrom8i1r17ljr6g4qu8@4ax.com>:
>>>>
>>>>>On Fri, 14 Jun 2024 07:43:53 GMT, Jan Panteltje <alien@comet.invalid>
>>>>>wrote:
>>>>>
>>>>>>Interesting reading about spread-spectrum, also for on-board designs:
>>>>>>
>>>>>>
>>>>>> https://www.electronicdesign.com/technologies/power/article/55041243/monolithic-power-systems-choosing-the-proper-parameters-in-frequency-spread-spectrum-fss-design
>>>>>
>>>>>That's cool, except for the usual dreadful fake pcb image.
>>>>
>>>>Fake?
>>>>Sure some fun zig-zag loops in some tracks... ?
>>>>Why would anybody bother making artwork like that when you can just take a picture?
>>>
>>>I've wondered that. And when they use a picture, it tends to be some
>>>ancient crufty Dip-package board.
>>>
>>>I have rarely used wiggle traces to add delay, but the fake board
>>>images are full of them. And glowing traces. And vias without holes.
>>>
>>>Hey, the electronic designers here could post pics of our prettiest
>>>real circuit boards.
>>>
>>>>
>>>>
>>>>>We have a bunch of switchers that use our own FPGAs as the
>>>>>controllers, and I need to start up a project to make them
>>>>>spread-spectrum.
>>>>
>>>>I find it interesting, not much experience with spread spectrum,
>>>>but a lot with wideband FM modulation like for the old Ampex video recorders... VHS, Umatic, Betamax too.
>>>>So with a bit of luck you can send your commercials on a few hundred kHz :-)
>>>>
>>>>
>>>>>We don't want the ss modulation to show up in the DC outputs as ripple
>>>>>or anything audible.
>>>>.
>>
>>>>RF wideband filtering, inductors.. capacitors...
>>>>
>>>
>>>The jitter pattern needs to create spectral spreading at high
>>>frequencies but not change averages at low frequencies. There might be
>>>some math involved.
>>
>>Yes I'v heard about maaz
>>I do not see many tennis players use math to calculate how to move and where to point the ball.
>>Would take too long.
>
>Given the speed of measurable electrical nerve impulses, most sports
>should be impossible. Recognizing an image, one of millions, in
>milliseconds is even more improbable.
>
>Something else is going on.

In massive parallel:  Fit, extrapolate, intercept.

Joe Gwinn