Environmental Engineering Reference
In-Depth Information
It is worth noting that the frequency compensation of a three-pole
amplifier can be performed following the same procedure as for an
equivalent two-pole amplifier with a loop gain given by
The time constant of the equivalent second pole equals the sum of the
second and third pole time constants of the three-pole amplifier. In other
words, the equivalent pole is
and the frequency and time-domain behaviour of the closed loop amplifier
can be approximated with those developed in section 4.2.
4.5
THREE-POLE FEEDBACK AMPLIFIERS WITH A PAIR OF
COMPLEX AND CONJUGATE POLES
Another common situation for a three-pole amplifier is when a dominant
pole occurs in conjunction with a pair of complex conjugate poles. We use
the symbolism introduced in section 4.3 to express such a loop-gain transfer
function
