1. Soft-Switching DC-DC Converter Is to shape the voltage or the current waveform by creating a resonant condition to: Force the voltage across the switching device to drop to zero before turning it ON  Zero-Voltage Switching (ZVS) Force the current through the switching device to drop to zero before turning it OFF  Zero-Current Switching (ZCS)

2. Overview Many soft-switching dc-dc converter families were introduced in the open literature The objectives of these topologies are to develop high switching frequency converters with high power density and high efficiency This was accomplished by adding additional components to the power stage. Steady-state analysis tend to be time consuming. Provided little insight into the converter switching-cell operation.

3. Hard-Switching and Soft-Switching Hard-Switching Zero-Current Switching Zero-Voltage Switching

4. Why Soft-Switching? Reduce switching losses especially at high switching frequencies Increase the power density, since the size and weight of the magnetic components is decreased by increasing the operating frequency Reduce the Electromagnetic Interference (EMI)

5. Conventional DC-DC Converters (Hard-Switching) Buck Boost Buck-Boost Cuk ZetaSepic

6. Switching-Cell Sharing All the Conventional DC-DC Converters shares the same switching-cell With different orientation of the cell in a specific converter The Conventional DC-DC Switching-Cell

7. Analyzed Soft-Switching Cells

8. Zero-Voltage-Switching Quasi-Resonant ZVS-QRC Switching-CellZVS-QRC Cell Basic Switching-Waveforms

9. ZVS-QRC Family ZVS-QRC Buck ZVS-QRC Boost ZVS-QRC Buck-Boost ZVS-QRC Cuk ZVS-QRC ZetaZVS-QRC Sepic

10. Zero-Current-Switching Quasi-Resonant ZCS-QRC Switching-CellZCS-QRC Cell Basic Switching-Waveforms

11. ZCS-QRC Family ZCS-QRC BuckZCS-QRC Boost ZCS-QRC Buck-BoostZCS-QRC Cuk ZCS-QRC ZetaZCS-QRC Sepic

12. ero-Current-Transition PWM Cell ZCT-PWM Switching-Cell ZCT-PWM Cell Basic Switching-Waveforms