Silliness is obviously in the eye of the beholder.
Cheers
Phil Hobbs
-- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 hobbs at electrooptical dot net http://electrooptical.net
But, the venerable LM7805 is +/- 5% over temperature. So, you have only ever used LM7805A?
Doesn't work that way. You need to test the DISTRIBUTION, so it'll take thirty or so samples, preferably with different datecodes, and it'll also require an environmental chamber (or some really good thermal modeling). Your testing would have to include multiple input voltages. Then you'll have the day-zero specs, but soldering stresses, and ten years aging tests, will require more work (or good modeling); it isn't practical to 'find out' like that.
...and at best you're only finding out what the part is today. The manufacturer can change anything tomorrow. As long as the datasheet doesn't change, he's good. No, I won't design to exceed the abs-max, either. Ever.
5.3V is the nominal. You haven't calculated in all of the other factors to see if abs-max is being exceeded. You're not even concerned about the abs-max. Not good.
I've never used either.
-- Rick
Kind of uninformed about testing and reliability you are. A useful amount of data could be found by testing to destruction of say 20 parts from each of 20 different lots. That is 400 parts to test to destruction. Then you could have a measured estimate of the real maximum voltage capability. BTW the manufacturer has done this and that is what produces the data sheet limit (voids any warrantee type claim). Does this help you understand?
?-)
have
you
Except the point you think you have doesn't exist in reasonable engineering. That is what everybody is trying to tell you.
?-)
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