Modeling of cross-regulation in multiple-output flyback converters

In this paper, the complex operation of multiple-output flyback power converters is explained in terms of the extended cantilever magnetics model. Analytical results are derived that can accurately predict steady-state cross-regulation properties of a power converter with any number of outputs and with arbitrarily complex magnetics configuration. Two snubber configurations are considered: a passive voltage-clamp snubber; and an active-clamp snubber. Predictions of the model are verified by experiments. The analytical models are the basis for a discussion of magnetics design guidelines that can result in improved cross-regulation in multiple-output flyback power converters.