Abstract
A method is provided for current compensation. The method is based on division-summation (D-Σ) control for DC/DC converters. Digital controls on D-Σ and inductance change are achieved. Loop gain can be quickly adjusted. A disadvantage of average current-mode control (ACMC) is improved. The disadvantage is a reduction of the response speed caused by the filter within the current loop. The present invention uses current samples of carrier center to ensure to acquire an average inductor current value in each switching cycle. By doing so, a lack of fidelity of peak current-mode control (PCMC) is solved. The lack of fidelity is due to the amount of error between peak value and average value. Besides, the present invention uses a table of the inductance values along current changes to achieve compensation of duty cycle ratio. The table is built in a single chip. Thus, the present invention solves the shortcomings of PCMC and ACMC and allows wide inductance changes. When the inductance value attenuates as the current becomes big, the converter can still accurately track the command of reference current. Furthermore, the volume of the iron core can be significantly reduced.