A switched mode voltage regulator has a digital control system that
includes dual digital control loops. The voltage regulator comprises at
least one power switch adapted to convey power between respective input
and output terminals of the voltage regulator and a digital controller
adapted to control operation of the power switches responsive to an
output of the voltage regulator. The digital controller further comprises
dual digital control loops in which a first control loop provides high
speed with lower regulation accuracy and a second control loop has high
accuracy with lower speed. Thus, the digital control system provides the
advantages of both high speed and high regulation accuracy.