Patent ID: 6198261
Filing Date: 2001-03-06
Classification: H02M

Abstract:
A method of operating a voltage regulator having an input terminal to be coupled to an input voltage source, an output terminal to be coupled to a load, and at least one switching circuit to intermittently couple the input terminal and the output terminal, comprising:determining an estimated current for each of the at least one switching circuits, each estimated current representing a current passing through an inductor in an associated switching circuit;calculating a desired total output current through the inductors which will maintain an output voltage at the output terminal at a substantially constant level;calculating an upper current limit and a lower current limit, the average of the upper current limit and lower current limit being equal to an individual desired output current for one of the inductors; andfor one or more of the switching circuits,comparing the estimated current to the lower current limit and causing the switching circuit to couple the input terminal to the output terminal if the estimated current falls below the lower current limit, andcomparing the estimated current to the upper current limit and causing the switching circuit to couple the output terminal to ground if the estimated current exceeds the upper current limit.