Path: ...!Xl.tags.giganews.com!local-1.nntp.ord.giganews.com!nntp.supernews.com!news.supernews.com.POSTED!not-for-mail NNTP-Posting-Date: Thu, 06 Jun 2024 17:57:50 +0000 From: john larkin Newsgroups: sci.electronics.design Subject: Re: AD5791 Date: Thu, 06 Jun 2024 10:57:50 -0700 Message-ID: References: User-Agent: ForteAgent/8.00.32.1272 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Lines: 30 X-Trace: sv3-sElcUHbPf9Bqu0tRDZAUalzCNT7/pJUeyM0VKcquxmrhxR3EnQMNE0tNQomZjjfgfLcOZaQM3ODiit2!O/hRAQOyAI9MtDZqFEwHuhZAc6hNDXu45AkW5RCKimhPqgx4QLgOQbXWazeUo6+/mrFOk2CR7jjt!OjRxZg== 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: 2082 On Thu, 06 Jun 2024 10:15:45 -0700, boB wrote: >On Tue, 04 Jun 2024 10:48:00 -0700, john larkin wrote: > >>https://www.analog.com/en/products/ad5791.html >> >>That's an amazing part. 20 bit DAC with 1 PPM accuracy and 0.05 PPM >>per degree C tempco. >> >>My main gripe is its 3.4K output impedance, which makes a lot of >>Johnson noise. I suppose I could run a bunch in parallel. > > >Nice part but costs way too much for any products we make. > >boB What do you make? We live on the lunatic fringe of electronics, things that are really hard to do, things with extreme exponents. It makes money because it has little competition, but the money is a side effect. I do it because it's fun. There must be something cool that we can do with a 1 PPM accurate DAC. TI has a 20-bit delta-sigma DAC that's about $12, but it's only linear to 15 PPM. I don't understand how a d-s DAC or ADC can even be that good. It would seem to need femtosecond edge accuracies inside.