A system and method for DC/DC conversion are provided in which a high
accuracy digital pulse width modulator controller circuit controls a power
switch to obtain a desired DC output. The control circuit amplifies the
difference of a DC output sample in relation to voltage reference. The
amplified difference is then compared with a portion of the DC output. The
compared result is used for controlling the power switch. A ripple coming
from the DC output side is overlaid upon either one of the inputs to the
comparator depending upon the polarity of the ripple signal.
