On Mon, 07 Feb 2005 16:55:42 -0000, (David DiGiacomo)
wrote:

In article ,
Roy Lewallen wrote:
As I recall, only transistors designed as saturated
switches (2N918 comes to mind, but it's been a long time, so don't quote
me) are gold doped. Ones which aren't, and I'm quite sure the 2N3904 is
in that category, will have long reverse recovery times so will make
poor RF rectifiers. Circuits became too fast for saturated switches
long, long ago, so I'd be surprised if gold doping is done any more
except for replacement transistors in very old equipment.

Don't people still use 2N2369As, or at least the plastic version?

Yes.

If not, what do they use instead?

CMOS has no storage.


(Does gold doping work for PNP transistors? I don't see why it wouldn't,
but I've never seen a specific reference to a gold-doped PNP.)

No. Doping "sex" (of gold) is wrong for the N-type base, which is
where you're trying to induce recombination.

...Jim Thompson
--
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