Study On Active Devices Modeling Method For EMC And SI Simulation

The electromagnetic compatibility and signal integrity problems of the system brought about by the rapid development of integrated circuits have become increasingly prominent.In order to reduce the cost of system design,it is necessary to perform circuit simulation on the system at the beginning of integrated circuit design.Due to the limitations of the active device model library of the simulation software,all device simulation models cannot be provided,so it is urgent to establish a systematic active device modeling method.In the thesis,the active devices are classified,and the appropriate modeling methods for various types of active devices are introduced respectively,and the accuracy of the model and the modeling method is verified through the comparative analysis of simulation and experimental results.The main study contents are as follows:(1)It is a study on MOSFET modeling method based on parameter fitting.For discrete devices such as MOSFET S,simulation modeling is carried out by using the method of model parameter fitting.Taking the NMOS CYC35N07Z05 as an example,the basic structure of the MOSFET is first studied,and the MOSFET model is equivalent to two parts including the parasitic parameter MOSFET and the body diode.Secondly,the parameter fitting is determined based on the SPICE Level3 model,and the physical meaning of the parameters of each model and the coupling relationship between them are studied.Then,the characteristic curve data is obtained through experimental testing and data processing,and the curve is fitted with the fitting software to obtain the parameter values of each model and obtain the final simulation model of the MOSFET.Finally,the model and the modeling method are verified by simulation and experiment.(2)It is a study on voltage comparator modeling method based on equivalent circuit.For more complex analog integrated devices,the method of constructing macro models is used for simulation modeling.Taking the comparator SF293 MFRH as an example,the basic structure of the comparator and the construction method of the macro model are firstly studied,and the macro model of the comparator is established by the port characteristic construction method.Secondly,the circuit of the comparator is divided into functional blocks and equivalent,and the macro model of the comparator is established by using devices such as triodes and controlled sources.Finally,the accuracy of the built macro model is verified by both simulation and experiment,and the simulation model of the op-amp SX4132 MCRH established according to this method is simulated and verified to verify the accuracy of the modeling method.(3)It is a study on modeling methods of analog digital converters based on behaviorlevel characteristics.For analog integrated devices and digital integrated circuits with digital ports,the method of establishing input and output characteristics is used to simulate and model.Taking the analog-to-digital converter JMAX1031B-5 as an example,the basic structure of the analog-to-digital converter and the characteristics of IBIS model are firstly studied to determine the information needed to establish IBIS model.Secondly,the pin functions of the data manual of the analog-to-digital converter are studied to determine the buffer type and obtain I/V and V/ T curves through experiments and data processing.Then according to the IBIS model information specification,the IBIS model including header file information,pin information and buffer model information is established.Finally,the validity of the model and the modeling method is verified by methods such as syntax verification and comparison between simulation and experiment.