A digitally-controlled, DC/DC converter includes at least one
switched-mode power stage for the purpose of converting an input voltage
(Vin) into an output voltage (Vout); the power stage including at least
one controllable switching device, which is turned ON and OFF by a
control device with temporal resolution .DELTA.t. The converter further
includes a duty cycle control mechanism for controlling the duty cycle of
the controllable switching device, the duty cycle control mechanism
including a mechanism for estimating the output voltage error; a
mechanism for estimating the target duty cycle; a duty cycle quantization
mechanism for determining, for a target duty cycle estimate, a first set
of quantized ON time/OFF time pairs suitable for controlling the
switching device; and a selector mechanism for determining the turn ON
and turn OFF times of said controllable switching device by choosing,
cycle by cycle, an ON time/OFF time pair from a second set of quantized
ON time/OFF time pairs, derived from said first set, choosing in such a
manner that the amplitude of the output voltage error is continually
minimized. To compensate for the load-dependent effects of parasitics,
the second set of quantized ON time/OFF time pairs is adjusted
continuously, to insure optimum performance at all load levels.