Path: ...!Xl.tags.giganews.com!local-1.nntp.ord.giganews.com!nntp.supernews.com!news.supernews.com.POSTED!not-for-mail NNTP-Posting-Date: Mon, 24 Jun 2024 14:53:56 +0000 From: john larkin Newsgroups: sci.electronics.design Subject: Re: Interesting reading about spread-spectrum, also for on-board designs Date: Mon, 24 Jun 2024 07:53:56 -0700 Message-ID: References: <45mo6jhcq8kisjmbrom8i1r17ljr6g4qu8@4ax.com> <1o0j7jta3sqmtpp0ogu60jpf1lduql59q5@4ax.com> User-Agent: ForteAgent/8.00.32.1272 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Lines: 29 X-Trace: sv3-Ei90ksgHYZoK8WAkFqt0X2zZJjyKV18GsfwYvMsKaLjxaK5EK1ZHEn8deTfCXmmscJDiQIX7yxMHbxq!pE/Nv2l7VijWxwKh04fZAwlyiw8vxb5jXhJ8Kq9s64ozzRyyXSHody5DJVmXfUztVWfJ4dpt6t2f!1wjwUA== X-Complaints-To: www.supernews.com/docs/abuse.html X-DMCA-Complaints-To: www.supernews.com/docs/dmca.html X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint properly X-Postfilter: 1.3.40 Bytes: 2172 On Mon, 24 Jun 2024 10:32:50 -0400, Joe Gwinn wrote: >On Fri, 14 Jun 2024 07:55:14 -0700, john larkin wrote: > >>On Fri, 14 Jun 2024 07:43:53 GMT, Jan Panteltje >>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. >> >>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. >> >>We don't want the ss modulation to show up in the DC outputs as ripple >>or anything audible. > >Standard issue in radar systems. > >Take the FFT of the ss modulation and develop a pseudo-random sequence >generator which shows no structure in the spectrum. > >Joe Gwinn And has minimal low-frequency content.