Re: Datasheets and probability

Martin Brown <'''newspam'''@nonad.co.uk> wrote:

On 15/12/2024 01:50, John S 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.

 
It is actually a rather deep and difficult to answer question in general
because for some components the answer can be "it depends".
 
Semiconductors I generally take it to mean ~3 sigma either side of the
mean but design with a bit of extra margin so the 0.5% tail doesn't
cause trouble.

 
Nah, all parts nowadays follow their spice models exactly.

Cheers

Phil “alias Dr Tung In Chic” Hobbs


--
Dr Philip C D Hobbs  Principal Consultant  ElectroOptical Innovations LLC /
Hobbs ElectroOptics  Optics, Electro-optics, Photonics, Analog Electronics