[sdiy] op amps [was: Re: TI SN74LS624N, worth buying?]

[David G Dixon]

> True, but some circuits are even more sinister, they can 
> depend on the internal design of the 741 such that it will 
> just not work. Jürgen had that experience for instance.

I personally tend to avoid those sorts of circuits like the plague.  If I
can't understand a circuit based on the so-called "golden rules" of opamps,
then I don't bother with it.

Concerning oscillations and their avoidance, this seems to me to be a bit of
a black art, and something I've had to learn by bitter experience.  It is
tempting to throw little caps into every negative feedback loop to avoid
oscillations, but this can also do more harm than good (particularly in
filter cores).  For me, the following general rule has evolved: provide for
stability caps on layouts whenever possible, but leave them off unless they
are truly required.