US Sources for old ICs

[Paul Koning]

>>>>> "der" == der Mouse <mouse at rodents.montreal.qc.ca> writes:

 >> Of course manufacturers don't want to use DIPs.  They are
 >> electrically inferior.

 der> Why?  Is it just the bulk lead capacitance, or is there some
 der> other way in which a DIP package is electrically deficient?

Lead capacitance, lead inductance.  And you rarely can use more than
one or two power/ground leads.  Modern high speed devices often have
dozens of power and ground connections to keep the power clean.

I suspect SMTs may be thermally better, too -- same reason, shorter
lead length from die to PCB.

 >> [DIPs] are bigger, slower, not RoHS compliant, ...

 der> Bigger, yes.  Slower, I can't see why, unless it's bulk
 der> capacitance.  RoHS compliant, that's a historical accident
 der> rather than anything inherent in DIPs, isn't it?  I can't see
 der> any reason why a DIP couldn't be made as cleanly and compliantly
 der> as the corresponding surface-mount part.

Agreed.  But I don't expect any lead-free DIPs.  RoHS is forcing
manufacturers to look at every part they sell, and decide either to go
through the expense of updating it, or to drop it as obsolete or too
low volume to be worth the trouble.

    paul