[time-nuts] EFC tracking

[Magnus Danielson]

On 06/29/2010 01:45 AM, Hal Murray wrote:
>
>> The one I'm building up is a ADS1278
>> http://focus.ti.com/lit/ds/symlink/ads1278.pdf
>> There are others in the series with fewer inputs. As with a lot of
>> converters, there isn't a whole lot of data on them.
>
> What are you looking for?
>
> There is a section of DC parameters on page 3.
>
> No missing codes:  24 bits
> INL: 0.0003% (typical), 0.0012% (max)
> Offset drift: 0.8 microvolts/C (typical)
> Gain drift: 1.3 ppm/C (typical)

There are also some useful plots relating to temperature dependence 
among other things, things relating in particular to long term aspects.

Choosing the right Vref value can be among the things to do to get the 
performance.

Also, TI claims it to address both the DC precision and audio 
properties. Looks like a good choice to me. Naturally, things must be 
tested and tried.

Cheers,
Magnus