On Tue, 26 Feb 2002, Edson Brusque wrote:

> >Use a comparator instead of an op-amp. op-amps do not make good
> >comparators in many cases.

  The greatest mistake that many people do, is unknowing the extraordinare
advantage of an operational amplifier used as comparator against a classic
open colector comparator, OA will have a smallest offset and the slew rate
can be increased by supressing any lad and/or lag capacitor correction. In
fact any phase correction must be avoid when OA is used as comparator.
Whith this rule any fast OA become the best comparator. A good example of
how to don't design a comparator is the internal f62x structure which have
an offset greater than many common operationals and required some
histeresys for a nice switching.

best, Vasile

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