Unified Small-Signal Model for DC–DC Converters Based on the Four-State Switching Cell in Discontinuous Conduction Mode

This work presents a unified small-signal modeling approach for converters employing the four-state switching cell (4SSC) operating in discontinuous conduction mode (DCM). The method involves the analysis of generic waveforms associated with a three-terminal representation similar to the pulse width modulation (PWM) switch model. Unlike state-space averaging (SSA), the method requires only the use of basic concepts involving electric circuits. The derived dc and ac models are valid for any operating region defined in terms of the duty cycle. Thus, one can easily obtain several transfer functions. The model response in both the frequency and time domains is compared with that of the switched converter to validate the theoretical analysis.