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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.
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