A Systematic Method for the Stability Analysis of Multiple-Output Converters

The dynamics of multiple-output dc-dc converters are discussed. A multi-input-multi-output (MIMO) feedback system model incorporating effects of the output fluctuation is derived for the converter. Based on system theoretic tools, a set of stability conditions is obtained for the MIMO model; the result is used to formulate a stable margin. A practical five-output converter was selected for illustration of the proposed analytic tool. The effects of the input filter and coupled inductor on system stability margin are investigated.