Hi:

I haven't been following this thread but see it's about making a DAC with a lot 
of bits.
While researching a Quantec GPS receiver I discovered a patent that for a 4 bit DAC to be used to drive a precision oscillator.
http://www.prc68.com/I/Q5200.shtml#Patent
It depends on using the carry out from an NCO that has a 48 bit input word.

PS HP/Agilent has some instruments with very high quality programmable DC sources such as the 4352 VCO tester. These have very low noise but I forget how many bits.

Mail_Attachment --
Have Fun,

Brooke Clarke
http://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html
http://www.prc68.com/I/DietNutrition.html
Andreas Jahn wrote:
Hello,

its not only the plastic (epoxy) package.
Its also the epoxy PCB which creates package stress to the die.
And I do not believe that any "slots" make it significantly better.
Thats why I use the AD586LQ; and soldering only one pin to the PCB.
(the others with thin VERO-wire).

With best regards

Andreas

Am 17.08.2015 um 18:46 schrieb Daniel Mendes:

Look at LT6655 datasheet, page 14, about long term drift of MS8 versus LS8 package. If others refferences are as bad regarding moisture then i think this may be a problem at this level of accuracy.....

Daniel

Em 17/08/2015 13:29, Andreas Jahn escreveu:
Hello,

I would rather use a reference with lower tempco than the LT1021. (typical 
7ppm/K)
E.g. (selected) AD586LQ or MAX6350.
Or at least LT1236AILS8 with around 3ppm/K.
The self heating alone gives around 3 deg C temperature difference.

With best regards

Andreas

Am 17.08.2015 um 18:19 schrieb Attila Kinali:
On Mon, 17 Aug 2015 15:38:37 +0000
"Poul-Henning Kamp" <[email protected]> wrote:


You mean the AD7177-2? That seems to be quite hard to get by.
I was thinking of the TI part intended for seismic applications.
Hmm. The ADS1262 does indeed seem quite easily available.
My goal was to stay below 30-40USD for the whole DAC if possible.
But yes.. it might not be possible.
I don't think it is.  The necessary voltage reference will set you
back almost that much...
I thought about using the LT1021. I don't need the long term
stability of the LTZ1000 and the LT1021 is available for less than 10USD.

But from the discussion here, think i have to go back and see whether
i really need such an high resolution or whether 20bit wouldnt be already
enough. Then i could get away with a 20bit DAC like the DAC1220.

Thanks

            Attila Kinali


_______________________________________________
volt-nuts mailing list -- [email protected]
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
and follow the instructions there.

_______________________________________________
volt-nuts mailing list -- [email protected]
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
and follow the instructions there.

_______________________________________________
volt-nuts mailing list -- [email protected]
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
and follow the instructions there.


_______________________________________________
volt-nuts mailing list -- [email protected]
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
and follow the instructions there.

Reply via email to