yes, i know it isn't usually specified, and the on to off time is
important for efficiency usually, but surely 1n4004 diodes turn on more
slowly then 1n4148, the switching speed is related to the junction size
and barrier thickness, and other parameters of the diode isn't it?=20
surely diodes that switch off fast switch on fast, and diodes that
switch off slowly switch on slowly.  there's the junction capacitance if
nothing else.  i know transistors have similar speeds in turning on and
off, surely diodes behave in a similar fashion?  if not, it would be a
terribly useful loop hole.

Olin Lathrop wrote:
>=20
> Philip Stortz wrote:
> > i think you want the fastest
> > diodes you can reasonably get to protect the other components, slow
> > diodes allow the voltage to rise to a higher level before it is
> > clamped
> > to a supply rail.
>=20
> This is a common misconception.  Diode speed ratings generally refer to=
 the
> reverse recovery time (on to off), not off to on.  The off to on time o=
f
> silicon diodes is not an issue in the vast majority of cases.  Many dat=
a
> sheets don't even specify it.
------

--=20
Philip Stortz--"In Germany they came first for the Communists, and I
didn't speak up because I wasn't a Communist.=20
Then they came for the Jews, and I didn't speak up because I wasn't a
Jew.=20
Then they came for the trade unionists, and I didn't speak up because I
wasn't a trade unionist.=20
Then they came for the Catholics, and I didn't speak up because I was a
Protestant.=20
Then they came for me, and by that time no one was left to speak up."
-- Martin Niem=F6ller, 1892-1984 (German Lutheran Pastor), on the Nazi
Holocaust, Congressional Record 14th October 1968 p31636.

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