On 4 November 2016 at 16:03, David Forbes <dfor...@dakotacom.net> wrote: > Martin, > > Yes, I have read that app note. I know all about good layout practice. It > does not address my problem that the capacitors are built in. I even sent a > query to the Maxim app engineers. They had no solutions, other than spending > lots more money for their high-end product.
I take it you picked a crystal to match their spec (12.5pF, 45KOhm)? If so, how much do you trust it? Did you try others? Maxim, while sometimes a bit weaselly, do tend to mean what they say on datasheets. If you want that cheap RTC, but your own trimmable oscillator, then why not? Silicon's cheap, and if you've got the board space, why not do that, and drive the RTC's Xin? It'll cost a little power, of course. Or, for cheapness, just trim at high level in software, bang a leap-second in or out at midnight, if these things are reliably off... Accumulate them and apply however many you need when you wake, as long as you can store the time that you went to sleep. That said, DS3231 avoids a lot of this messing about. I use and like it. Steve -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to neonixie-l+unsubscr...@googlegroups.com. To post to this group, send an email to neonixie-l@googlegroups.com. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/CALobHexNLxu%3D62_kxPxxVspDq_QgPStoK%3DU%3Dv9M_Km6MenqaBg%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
