X-Authentication-Warning: delorie.com: mail set sender to geda-user-bounces using -f X-Recipient: geda-user AT delorie DOT com Message-ID: <20201215033416.3061.qmail@rahul.net> Date: Mon, 14 Dec 2020 19:34:16 -0800 To: geda-user AT delorie DOT com Subject: Re: [geda-user] Variable voltage supply from fixed In-Reply-To: References: <84c207a9-df84-c244-96ee-b7e05795d491 AT nksb DOT online> X-Mailer: VM 7.19 under Emacs 26.1 From: conover AT rahul DOT net (John Conover) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Reply-To: geda-user AT delorie DOT com Errors-To: nobody AT delorie DOT com X-Mailing-List: geda-user AT delorie DOT com X-Unsubscribes-To: listserv AT delorie DOT com Precedence: bulk Off subject, but I have a Xynetic pen plot of the uA431 hanging on the wall from my days at Fairchild, c. mid 70's. The temperature characteristics of the band gap reference were optimized using Lagrangian techniques and verified with a new simulation program out of Berkeley called Spice. The last I heard, (several years ago,) the Fairchild Computer Vision DB was formatted to current stepper mask DB standards, and was still in production after Fairchild was acquired by et al, ending up at TI, via National. But that's just valley gossip. John gene glick (geneglick AT optonline DOT net) [via geda-user AT delorie DOT com] writes: > > TL431 is a personal favorite. It works very well as a shunt regulator or > with a transistor to form a higher current series regulator. Both > good...depends on the application. > > You did not mention noise or temperature. If noise is important to you, > then you'll need to find a regulator that exposes the voltage reference so > you can filter it. Temperature can affect some of these regulators. I've > run the TL431 to 175C (and higher) with no problems. The band-gap reference > is really very stable. Some regulators have thermal shutdown at 160C. > -- John Conover, conover AT rahul DOT net, http://www.johncon.com/