Geoffrey S. Mendelson wrote in message
...
DaveM wrote:

Sometimes the mfrs make a line of transistors having very similar
characteristics, differing in only a few specific elements, such as Vce,
Ic(max), etc.

Sometimes they took the same transistor and tested it. Depending upon
the results, it became one part or the other.

Back when the IBM PC first came out you could buy memory that cycled
at 200, 150, 125 or 100 ns. There was only one production line.

Each chip was tested at 100ns (10mHz), if it passed it was maked -100
and sent off to be packaged. If it passed at 125ns (8mHz) it was marked
-125, and so on. If it did not pass at the lowest speed the chips were
sold at it was tossed.

Now the chips that failed would be sold on eBay as "untested". :-)

Geoff.

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Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM
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Replaced FT5415 with 2N5415 and working fine

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Diverse Devices, Southampton, England
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