FWIW, IMO any engineer who uses undocumented or uncontrolled parameters or instructions in a production design is a fool.
If you are that silly, you must fully specify the selection criteria. -John =============== > Bob Camp wrote: >> Hi >> >> Simply a few stories I thought I would share. >> >> Simulate design. Use manufacturer's published models. Build design. Note >> differences. Call manufacturer. Answer - switched die three years ago, >> Ft is now " much better " ( now 3x old parts ). >> >> Odd they never mentioned that to people who work for the same company. >> >> Simulate design, Build design, verify design, ship it for a few years. >> Odd things start to happen. Look at some parts. Package looks different. >> Ask around..... Line got moved to other side of big ocean. Process got " >> tweaked" beta is now 4x what it was. >> >> Again all inside the same company. Both cases were excused by industry >> standard specs that had no upper limit. >> >> We had whole departments devoted to tracking this sort of stuff. It >> still happened on a regular basis. 30 years later the specs on the >> devices and their published models are still the " old version " ones. >> > > > there are also designs that depend on "non-data-sheet" performance of > particular devices. There's a very low noise, very low leakage fet > popular in charge amplifiers. It has a JEDEC 2N number (which I can't > remember off hand), but only the ones from one particular company (in > England) actually work in the circuits, and even then, there's some hand > selection involved. > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
