[time-nuts] EFC divider resistors

Robert LaJeunesse rlajeunesse at sbcglobal.net
Fri Jan 31 20:38:31 EST 2014


Must be military prices. If using 5 PPM resistors in the build a reference much better than that isn't needed, especially if the temperature is somewhat controlled, like time nuts do. A commercial 3 PPM/C part, the LM4140A, is $4.54 each in singles. At 2.2uV p-p it's reasonably quiet as well.

Considering stability influences, what provides the DAC reference? That's rather important as well. 

Bob LaJeunesse

I'd also note the 2 PPM ratio tracking dividers, the MAX549x series, can be had in the $3.49 range, also not all that expensive.



>________________________________
> From: Bob Camp <lists at rtty.us>
>To: Bob Stewart <bob at evoria.net>; Discussion of precise time and frequency measurement <time-nuts at febo.com> 
>Sent: Friday, January 31, 2014 7:17 PM
>Subject: Re: [time-nuts] EFC divider resistors
> 
>
>
>... A good voltage reference will set you back about $50 or so. 
>


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