1. Quasi-square-wave ZVS converters
A quasi-square-wave ZVS buck
Resonant transitions but transistor and diode conduction intervals are similar to PWM
Tank capacitor is in parallel with all semiconductor devices, hence all semiconductors operate with ZVS
Peak currents are increased, and are similar to DCM
Peak voltages applied to semiconductors are same as PWM
Magnetics are small, and are similar to DCM

2. Interleaved quasi-square-wave buck converters as VRM

3. Quasi-square-wave versions of other converters
Flyback
Boost
Single transistor version of switch is restricted to 0.5 < µ < 1
So for boost, M > 2
For flyback, M > n
Boost inductor and flyback transformer are very small, and are similar to DCM devices

4. Quasi-square-wave ZVS converters
A quasi-square-wave ZVS buck
Resonant transitions but transistor and diode conduction intervals are similar to PWM
Tank capacitor is in parallel with all semiconductor devices, hence all semiconductors operate with ZVS
Peak currents are increased, and are similar to DCM
Peak voltages applied to semiconductors are same as PWM
Magnetics are small, and are similar to DCM

5. Goal: Find steady-state solution for this resonant switch cell Approach: State plane analysis followed by averaging of terminal waveforms

6. Interval 1 Q1 conduction Begins when Q1 starts to conduct
For ZVS operation, this occurs when D1 had been previously conducting
Circuit
Initial conditions
Dynamics
What ends interval
Endpoints
Length of interval

7. State plane

8. Interval 2 Dead time Circuit Initial conditions Dynamics
What ends interval
Endpoints
Length of interval

9. Interval 3 D2 conduction Circuit Initial conditions Dynamics
What ends interval
Endpoints
Length of interval

10. Interval 4 Dead time Circuit Initial conditions Dynamics
What ends interval
Endpoints
Length of interval

11. Interval 5 (1) D1 conduction
Circuit
Initial conditions
Dynamics
What ends interval
Endpoints
Length of interval

12. Waveforms

13. Average switch input current

14. Average output current

15. Average output current, p. 2

16. Control input: transistor/diode conduction angle 

17. A way to solve and plot the characteristics

18. Solving, p 2

19. Results: Switch conversion ratio µ vs. F

20. Switch conversion ratio µ vs. 
Course website contains Excel spreadsheet (with function macros) that evaluates the above equations and can plot the above characteristics.