Construction Of The Macromodel For PWM Power Device

With the development of integrated circuits, the integrated circuit and the circuit characteristics are becoming more and more complex. The transistor level simulation of IC strongly limits the speed of circuits'analysis. IC modeling has been widely used in digital, analog and mixed signal circuits, due to its high efficiency in circuit simulation and verification.This thesis consists of three parts. In the first part, the modeling of sample circuit, ideal switch and comparator using SPICE is completed. The digital gate circuit model is attempted to construct, and the modeling of some digital circuits include the numeric comparator is accomplished.In the second part, firstly, the principle of switched power is discussed, including four structures (Buck, Boost, Invert, Cuk), two modulation methods (PWM, PFM) and two control mode (voltage control, current control). Secondly, the macromodel of op-amp, PWM, SCHMITT, and over temperature shutdown circuit .etc are established. Simulation based on these generated models is much faster than that of transistor level analysis, at the same time the precision is high.In the third part, the SPICE convergence in the constructing and modeling is concerned,solutions and approaches for SPICE non-convergent problems in dc,dc sweep and transient analysis are discussed in detail.The macromodels of temperature sensor, over temperature shutdown and pulse width modulation circuits are created in this thesis.