Hi > On May 19, 2016, at 1:17 PM, Attila Kinali <att...@kinali.ch> wrote: > > On Thu, 19 May 2016 09:08:40 -0400 > Bert Kehren via time-nuts <time-nuts@febo.com> wrote: > >> Today GPS receivers are getting better by the year due to the fact that in >> order to save silicon the chips are getting smaller and the clock frequency >> goes up reducing saw tooth excursion. If it was not for hanging bridge >> filtering it on the input of a GPSDO would be simple without info from the >> receiver > > This assumptions do not hold true. GPS timing receivers are almost always > just standard receivers with special firmware and slightly modified hardware. > The normal GPS receivers are optimized for low power consumption as they > are integrated into mobile devices. As such, the clock frequency with which > the baseband processor runs will hardly change, as the frequency is the > biggest knob with which the power consumption can be tuned. > > The node size of microcontrollers is also kind of stuck, mostly due > to power consumption constraints. If you want a transistor to switch > off well and not just becomming a high valued resistor, you have to make > it big. Hence most microcontrollers have a process node size between 130nm > and 250nm. Few use 90nm (i'm only aware of the high end STM32 uC). Low power > microcontrollers can even use larger node sizes (350nm and larger). > > You can see this phenomena with the LEA modules quite clearly: > The LEA-4, -5, -6, -7 and -8 modules all use an internal 48MHz clock. > Even though there were 2 complete overhauls of the system in this ~13 year > timespan.
Which is why a lot of outfits have abandoned uBlox and moved on to other outfits that didn’t stall out. Bob > > 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.