droop and roll-off
Updated June 10,
here to go to our slang dictionary
New for June 2007! No,
we're not talking about fire safety (stop, drop and roll!) This
page seems almost unnecessary. Unless you've been to a design review
with technical presentations by managers, marketing types or other
Drop, droop and roll-off are
words used to describe phenomena such as voltage or power, with
respect to something else. Usually when that phenomenon is falling
below a lower specification limit. Many engineers don't analyze
the combined effects of drop, droop and roll-off when they look
at design margin.
Droop is used when you
are referring to a slope with respect to time. Let's put this in
a practice sentence...
storage capacitor is too small and we're getting excessive
voltage droop over the 20 mirosecond pulse.
Drop is used when you
are referring to a slope against distance. Let's put this in a practice
The voltage drop along that
drain bias line is killing the output power of our transmitter.
Roll-off is used when
you are referring to a slope with respect to frequency. Let's put
this in a practice sentence...
That damn TriQuint amplifier
has a gain roll-off right at the edge of our frequency band.
OK, now does everyone get it?