21 Apr
2012
21 Apr
'12
1:35 p.m.
My expeirence is that more compelx ICs are
noticably less reliable than
simple ones.
That's much too simple analysis even if it were correct. Failure rates in
ICs are primarily down to processing, packaging and handling (and to a
lesser extent die area), not complexity.
I would think the 555 had a much better lifetime than any
microcontrolelr
therefore.
You would be wrong however. Today's ICs have a much better lifetime.
Statistically today's commercial grade ICs have a significantly better
lifetime than military grade ICs of the 555 era.
The origianl 555 (as opposed to the 7555, etc) is large-ish junciton
bipolar and thus less likely to suffer static damage than a MOS
microcotnroller. It also has a much wider supply votaeg range and is
less
likely to be damaged by supply problems.
That's not a definition of reliability - it's one of robustness. Within
their specifications the 555 would be less reliable (IMHO of course).
And of coruse if a microcontroller fails, unless you have the program
to
put into it, you're stuck. If a 555 fails, well, there's a tube of 50
in
my spares box. And I cna go to any number of suppliers anf buy one.
Agreed, but off-topic ;o)