Sujet : Re: Practical resistor accuracy distribution
De : joegwinn (at) *nospam* comcast.net (Joe Gwinn)
Groupes : sci.electronics.designDate : 27. Apr 2024, 22:47:29
Autres entêtes
Message-ID : <00pq2jh2o2ru6qqlp4bs79f4bn5s95agu7@4ax.com>
References : 1 2 3
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On Fri, 26 Apr 2024 19:38:07 -0700, John Larkin
<
jjSNIPlarkin@highNONOlandtechnology.com> wrote:
On Fri, 26 Apr 2024 20:16:48 -0400, Joe Gwinn <joegwinn@comcast.net>
wrote:
>
On Sat, 27 Apr 2024 00:54:41 +0200, Klaus Vestergaard Kragelund
<klauskvik@hotmail.com> wrote:
>
Hi
>
I needed to look into distribution of accuracy of resistors.
>
Vendors don't have any info, but luckily some nice people online have
done measurements:
>
<https://www.eevblog.com/forum/projects/smd-resistor-distributions/>
>
<https://lambdafox.com/resistor-tolerances/>
>
The thing to be aware of is that resistor value distributions are
often wildly non-Gaussian. The classic example is where there are
grades, say 1%, 5%, and 20%. The 5% group will often have a hole that
happens to match the 1% distribution perfectly.
>
A lot of modern resistors are made with a relatively wide
distribution, and then machine-sorted into bins. In this case, many
of the bins will have uniform distributions. And so on.
>
Joe Gwinn
>
I suspect that they may laser trimmed and shipped, not binned.
>
One batch on a reel could be very close to one another.
Also possible, and maybe a combination of both?
But the fundamental point is that one must measure to be sure, unless
one is a large enough customer that the manufacturer will simply tell
you.
Joe Gwinn