[time-nuts] Last Call Group Buy Ublox LEA-6T

[Bob Camp]

Hi

> On May 19, 2016, at 1:17 PM, Attila Kinali <attila at kinali.ch> wrote:
> 
> On Thu, 19 May 2016 09:08:40 -0400
> Bert Kehren via time-nuts <time-nuts at 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
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