A regulating apparatus having an output node and being operative for
regulating the voltage level at the output node in response to a
reference signal provided as an input to the regulating apparatus. The
regulating apparatus includes a linear amplifier stage operative for
receiving the reference signal and being capable of sourcing current to
the output node when the reference signal indicates that a present
voltage level at the output node is less than a desired voltage level at
the output node. The regulating apparatus also includes a switching
regulator, which is controlled by the linear amplifier stage, and which
is operative for sourcing current to the output node when the amount of
current being sourced to the output node by the linear amplifier stage
exceeds a predetermined threshold.