In control theory the settling time of a dynamical system such as an amplifier or other output device is the time elapsed from the application of an ideal instantaneous step input to the time at which the amplifier output has entered and remained within a specified error band.
Settling time includes a propagation delay, plus the time required for the output to slew to the vicinity of the final value, recover from the overload condition associated with slew, and finally settle to within the specified error.
Systems with energy storage cannot respond instantaneously and will exhibit transient responses when they are subjected to inputs or disturbances.[1]
- ^ Modern Control Engineering (5th Edition), Katsuhiko Ogata, p.160