Path: ...!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: Martin Brown <'''newspam'''@nonad.co.uk> Newsgroups: sci.electronics.design Subject: Re: Ambient temperature control Date: Mon, 1 Jul 2024 12:24:29 +0100 Organization: A noiseless patient Spider Lines: 27 Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Mon, 01 Jul 2024 13:24:30 +0200 (CEST) Injection-Info: dont-email.me; posting-host="35db8fd2ae7dfd3a0903a28208df8930"; logging-data="1114412"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX190KoGTAKgcz1BsjHG3D4XyP7vTXzsjr6vDcnrCnsQsGg==" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:jHBMYPLALEGGG/yaRvu51BhhOHk= Content-Language: en-GB In-Reply-To: Bytes: 2197 On 01/07/2024 02:14, Don Y wrote: > Assuming you can keep a device in its "normal operating (temperature) > range", how advantageous is it (think MTBF) to drive that ambient > down?  And, is there a sweet spot (as there is a cost to lowering the > temperature)? There can be for some high performance low level OPamps. Deliberately running them as cold as is allowed helps take the LF noise floor down and by more than you would predict from Johnson noise. ISTR there was a patent for doing this back in the 1980's. Prior to that they tended to heat the front end to obtain temperature stability and low drift. https://ppubs.uspto.gov/dirsearch-public/print/downloadPdf/4883957 Made possible with the advent of decent solid state TECs. > > Also, is there any advantage to minimizing the hysteresis between > the ACTUAL operating temperature extremes in such a control strategy > (given that lower hysteresis usually comes at an increased cost)? Depends how temperature sensitive the thing is that you are protecting. The example I recall they were aiming for medium term stable 6 sig fig measurements with the lowest possible noise. -- Martin Brown