An actuation circuit for a switch element regulating the power consumption
of an inductive energy storage element in a switching converter, used to
convert an input voltage into an output voltage, is described. The
circuit includes a pulse width modulator circuit configured so as to
provide a pulse-width-modulated actuating signal for the switch element
depending on a regulating signal dependent on the output voltage and a
current measurement signal dependent on a current across the inductive
storage element. The circuit further includes an arrangement that
provides the current measurement signal, wherein the arrangement for
providing the current measurement signal is a measuring and regulating
arrangement, configured so as to simulate the current measurement signal
from a signal dependent on the output voltage, a signal dependent on the
difference between the input voltage and the output voltage, and at least
a first sampled value of a signal proportional to the current across the
inductive storage element during a period of the pulse-width-modulated
actuating signal.