Modeling And Simulation Of Mixed-signal Systems Based On Verilog-AMS

With the progress of semiconductor technologies,Integrated circiuts become more and more complex.also the chips of mixed-signal systems are more and more popular. Mixed-signal systems design use top-down method,so system level modeling which is the first step of mixed-signal system design plays a important role in system design. Present modeling methods of mixed-signal system which make system design low effiency have lots of shortcomings and limitations.this paper research a new method for mixed-signal system modeling,that is,a kind of method using Verilog-AMS.the new mothod have many advantages compared with the other methods.In order to research new mothod,I takes two typical mixed-signal systems,charge-pump PLL and sensor signal processing circuit,for example.In this paper, I analysed advantages and disadvantages among different kinds of modeling methods and the idea method of system modeling in mixed-signal system design. the principle of sensor signal processing circuit and its high level behavioural model have be presented,then the model has been described with Verilog-AMS.this paper introduces how the new method build high level behavioural models of analog and digital circuits and analog-to-digital and digital-to-analog interfaces.I can get lots of advantages through compared the behavioural model of the first order modulator with the second order modulator in SigmaDelta ADC and noise model and DAC verifiacation model using Verilog-AMS.lastly,I analyse every parts'principles of charge-pump PLL and high level behavioural model then set up high level behavoioural model and verification model.By means of building system level behavioural models of the charge-pump PLL and sensor signal processing circuit using Verilog-AMS,we can get a conclusion that the new method not only can be used extensively in mixed-signal system level modeling but also can overcome limitations of present methods.