Re: Datasheets and probability

John S <Sophi.2@invalid.org> wrote:

Hi, men -
 
There are sometimes 3 columns on a datasheet which may contain min, nom,
and max values. Like Vds for example.
 
Is there any probability tacitly assigned to the values? I know that
nominal is the average, and I assume that the value lies between the two
middle one standard deviation points.
 
1. Is that a valid assumption?
 
2. Is the min between one and two standard deviations down from the mean?
 
Thanks and I apologize for asking such a basic question in this
professional group.
 

Parameters often have a gaussian distribution, You then can expect typ
values as the center of the bell curve and min/max values are cut
offs. With cut off at 1 sigma, about 35 % of the part would be out of
tolerance, so cut off is at a higher sigma value, but manufacturers
will not tell you ar what value it is.
--
Uwe Bonnes                bon@elektron.ikp.physik.tu-darmstadt.de

Institut fuer Kernphysik  Schlossgartenstrasse 9  64289 Darmstadt
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