Single-Stage Single-Switch Input-Current-Shaping Technique with Fast-Output-Voltage Regulation

A new single-stage single-switch input-currentshaping (S4ICS) technique, which combines the boost-like input-current shaper with a continuous-conduction-mode (CCM) dc/dc output stage, is described. In this technique, the boost inductor can operate in both the discontinuous conduction mode (DCM) and CCM. Due to the ability to keep a relatively low voltage (<450 Vdc) on the energy-storage capacitor, this technique is suitable for the universal line-voltage applications. The voltage on the energy-storage capacitor is kept within the desirable range by the addition of two transformer windings. The principle of operation of the SICS circuit with a forward dc/dc converter is presented. Experimental results obtained on a 100-W (5-V/20-A) prototype circuit are also given.