Development of A Small-Signal Model for The DC-DC Buck Converter Based on The Three-State Switching Cell

This paper presents the small-signal modeling of a dc-dc buck converter based on the three-state switching cell (3SSC) using the PWM (pulse width modulation) switch model, which is a far simple approach if compared with other similar techniques e.g. average state-space modeling. The ac model is properly derived, which allows obtaining relevant transfer functions involving several variables. It is also shown that the Bode diagrams corresponding to the mathematical expressions obtained in the theoretical analysis are properly verified by simulation, being able to represent both operating conditions of the 3SSC i.e. nonoverlapping mode and overlapping mode. Finally, some results regarding the converter operation in voltage mode control are presented and discussed.