The overall small-signal model of the synchronous switch postregulator

The overall small-signal models of the synchronous switch postregulators (SSPR's) with the leading-edge or the trailing-edge modulation are developed. From the models, the effect of the main output to the auxiliary output when the SSPR is operated in the continuous conduction mode or in the discontinuous conduction mode can be predicted. Once the main output enters into the discontinuous mode, the performances of the auxiliary output will degrade very much, even with the help of the postregulation, but if only the auxiliary output enters into the discontinuous mode, the performance degradation of the auxiliary output can be less severe.