Path: ...!feed.opticnetworks.net!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: Cursitor Doom Newsgroups: sci.electronics.design Subject: Re: another fast one-shot Date: Wed, 12 Jun 2024 22:18:43 -0000 (UTC) Organization: A noiseless patient Spider Lines: 37 Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Injection-Date: Thu, 13 Jun 2024 00:18:43 +0200 (CEST) Injection-Info: dont-email.me; posting-host="9e44b9033915d845461a1fe37634cb05"; logging-data="1855333"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1+UGiKH7fXgxPN8OF4Zl8rMqg5Y8X8wODQ=" User-Agent: Pan/0.149 (Bellevue; 4c157ba) Cancel-Lock: sha1:SjyJhtCZpTpAxJjzcBSq3H/xSdA= Bytes: 2500 On Wed, 12 Jun 2024 11:11:28 -0700, john larkin wrote: > On Wed, 12 Jun 2024 17:22:49 -0000 (UTC), Cursitor Doom > wrote: > >>On Wed, 12 Jun 2024 09:33:17 -0700, john larkin wrote: >> >>> Here's another idea for a fast one-shot. This is the just-apply-money >>> version and should get close to 1 ns pulse width and should easily >>> trigger at 150 MHz. >>> >>> https://www.dropbox.com/scl/fi/1okfo8964bw5m53mjmxs6/ >>Pecl_One_Shot_1.jpg?rlkey=dwus6qjyqsynl2rv6uje2xxtj&raw=1 >>> >>> I can use the other half of the dual comparator elsewhere. This one >>> has programmable hysteresis too. >> >>Exposing my contemptworthy ignorance here no doubt, but what exactly is >>it that is fast about this design, John? And what would its application >>be? > > It would have a leading-edge prop delay of 350 ps, a minimum pulse width > just over 1 ns, and would easily trigger at 150 MHz. Integrated > one-shots, xxx123 types, are always terrible, even the obsolete ECL > ones. > > It would be a programmable delay in a number of possible products, > including some optical modulators. Just playing right now. > > More dollars could certainly do something faster, but as long as > customers connect boxes with cables, faster isn't worth a lot. Light > just moves too slow. > > Any suggestions for a faster one-shot? Not from me! I couldn't even design a PID controlled PLL without recourse to the 'net.