Ideas to Integrated Circuits links to a number of interesting, first person, stories about the development of modern electronic devices such as the GFI.
“The Characterization process of first silicon was an attempt to feel out how an IC would run in production. Things like beta and resistance would vary month to month. So a spec for a part needs to have tolerances that allow for these process variations. Otherwise a month will come along where parts cannot be shipped to a customer because the wafer sort yields are too low.
At the opposite end, the specs need to be tight enough so that all parts that ship to a customer are functional. It was soon discovered that testing GFI ICs like Op Amps could not meet this requirement. Even with including extra tests and specs which came from the customer, it was found that maybe one part in 5000 would fail to operate as a GFI. Investigations revealed that this would usually be due to a devices having two independent defects
which now and again would cancel each other out to allow the device to pass a DC spec.”
There is a lesson there for those who think companies are greedy, self interested entities out to screw the customer:
“It took maybe ten years before Levition realized why the extra testing was a real economical bargain for National Semiconductor. When Raytheon started supplying Leviton with GFI ICs, both Leviton and Raytheon eventually learned just how expensive customer returns are to both customers and vendors.”
In 1974, the GFI sold for $70. Things have changed. Lives saved and costs reduced. And that is only one story at idea2ic.com
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