Hi I’ve designed watch guts (long ago). It was at a time that you used an analog (motor) movement if you wanted really low power. The CMOS / LCD’s of that era were power hogs by comparison.
What you can put in a small / thin watch isn’t what you would use on a RTC board. My suspicion is that the leakage from a number of sources will indeed dominate the actual power consumption in a random build sort of application. (At least compared to 10’s of nano amps of power into the chip). Bob > On Mar 7, 2018, at 11:03 AM, Attila Kinali <att...@kinali.ch> wrote: > > On Wed, 7 Mar 2018 08:27:00 -0500 > Bob kb8tq <kb...@n1k.org> wrote: > >> Since we don’t often *need* the smallest cell made *and* we’re probably >> talking lifetime of the cell….. does 22 na vs 33 na matter? > > Not really. It starts to matter when you are space limited and don't > have space for a CR2032. > > At this level, though, every tiny bit of leakage matters. Finger prints, > dust, humidity, FR4... Going below 1µA in current consumption is like > going below 10^-12 in frequency stability, suddenly 1M is a low resistance. > >> Based on the previous data on the chip, I think I would just run the crystal >> all the time. > > The the watches (quartz with analog dials) I have run >5 years > on their batteries, an I am pretty sure they don't have a CR2032. > And at least one of them must have a TCXO. > > > Attila Kinali > -- > It is upon moral qualities that a society is ultimately founded. All > the prosperity and technological sophistication in the world is of no > use without that foundation. > -- Miss Matheson, The Diamond Age, Neil Stephenson > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.