Decoupled technique for the simulation of PWM switching regulators using second-order-output extrapolations

A hybrid time-domain simulation technique for pulse-width-modulated (PWM) switching regulators is presented. The methodology integrates the advantages of the simulation concepts for switched and nonswitched networks. A regulator is decoupled into dual-analysis components, namely, the power conversion stage (PCS) and feedback network (FN). The former component is simulated by a time-domain digital integration technique with stepwise analysis of the switches' state and automatic determination of correct topological configuration in the PCS operation while the latter one is analyzed by formulating a modified system difference equation and defining at each switching period with second-order extrapolations and corrections of the PCS and error amplifier outputs. Other superior features of this approach include: (1) elegant numerical method of determining the gate signals from the PWM modulator; (2) simple manipulations of numeric and algebraic equations; and (3) applicability to simulate regulators with multiple parameters feedback from PCS. The proposed methodology is illustrated with several examples. The simulated steady-state and large-signal transient waveforms are favorably verified with experimental measurements and available literature.