SMPC Circuit Topologies and Operation

In our discussion of SMPC circuits, the switching method has been assumed to be hard switching. In hard switching, the current and voltage stresses imposed on the switches and diodes are not considered (or minimized) by the control electronics. The duty cycle or frequency of the system is adjusted solely to maintain the required output voltage, current, or power. Switching losses in these systems can be quite high. 

In applications where high power density or thermal management is of prime importance, hard- switched converters are not feasible using conventional Si components. In these cases, resonant or quasi-resonant (also termed soft-switching ) topologies can be used. The electrical resonance is obtained through parasitic 

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