Method and apparatus for digital voltage regulation

The present invention relates generally to voltage regulators, and more particularly to control systems for switching voltage regulators. A digital voltage regulator has an input terminal coupled to an input voltage source, an output terminal coupled to a load, and a plurality of switching circuits to alternately couple and decouple the input terminal to the output terminal. An estimated current is calculated for each switching circuit, each estimated current representing a current passing through an inductor associated with the switching circuit. A total desired output current to pass through the inductors is calculated which will maintain an output voltage at the output terminal substantially constant. The switching circuits are controlled based on the estimated current and the total desired output current so that a total current passing through the inductors is approximately equal to the total desired output current.