DECOUPLED TECHNIQUE FOR THE SIMULATION OF PWM SWITCHING REGULATORS USING 2ND-ORDER-OUTPUT EXTRAPOLATIONS

A hybrid time-domain simulation technique for pulse-width-modulated (P WM) switching regulators is presented. The methodology integrates the advantages of the simulation concepts Tor switched and nonswitched net works. A regulator is decoupled into dual-analysis components, namely, the power conversion stage (PCS) and feedback network (FN). The forme r component is simulated by a time-domain digital integration techniqu e with stepwise analysis of the switches' state and automatic determin ation 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 extr apolations and corrections of the PCS and error amplifier outputs. Oth er superior features of this approach include: 1) elegant numerical me thod of determining the gate signals from the PWM modulator; 2) simple manipulations of numeric and algebraic equations; and 3) applicabilit y to simulate regulators with multiple parameters feedback from PCS. T he proposed methodology is illustrated with several examples, The simu lated steady-state and large-signal transient waveforms are favorably verified with experimental measurements and available literature.