>> - Bargain-price/cheapie/fallout zeners diodes are basically units that
>> fail to pass the manufacturer's final test. I was given a box of them
>> which was marked "semiconductor scrap". Some were usuable. Some were
>> not. None were first class.
>
> <snip>
>
>> quality semiconductors.
>>
> <snip>
>
> ::I wonder: What is the difference in "quality" between fallout and
>first-class, in Zeners?
A mixed bag.
>Having fabricated a lot of these (starting with
>undoped silicon), the "fallout" in manufacturing is usually -- oops! missed
>the target avalanche voltage! -- or -- oops! failed to meet another
>parameter such as leakage current below avalanche, or dynamic impedance
>(slope of Vz/Iz).
Inability to maintain constant V with <> I is the sticky wicket.
cheers, Steve
>...
- R. L. Measures, a.k.a. Rich..., 805.386.3734,AG6K,
www.vcnet.com/measures.
end
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