Multistage switching power supply circuits

A method for designing the output stage of switching power supplies by employing multiple stage circuit structures is presented. Using this method, the switching noise at the output of the power supply can be reduced dramatically, while keeping the cost of the circuit almost the same as that for a single stage supply. The method treats the output stage circuit from the viewpoint of a filter network, instead of that of energy storage. The analyses and results for the circuits are given