Analysis of Multiple-Outputs DC-DC Power Converter using Cross-Regulation

The electronic equipment often requires the need of power supply with several regulated and isolated dc output voltages. In order to accomplish this requirement, the energy-storage dc-dc converter using cross-regulation has been widely employed because of inherent advantages, ie, high efficiency, small size, light weight and simplicity of circuit configulation. In this type of converter, however, the steady state errors of the output-voltages can not be made smaller than some values even if the feedback loop gain is increased sufficiently. Further, the operation of this converter is easy to be unstable when the feedback loop gain and/or the total output power grows larger. In this paper, we analyze the steady state and the dynamic characteristics on the typical type of the multiple-outputs converter using cross-regulation. As the results of analysis, the mechanism of the cross-regulation, the dynamic response and the boundaries of the stability are clarified analytically. These results are verified by the experiments