The Research Of Board-level Analog Circuit Simulation Convergence

In the field of the fault diagnosis, the results of the fault circuit simulation could be used to build the fault dictionary of the circuit. However, during the circuit simulation, especially the fault circuit simulation, usually the non-convergence phenomenon takes place.The paper introduces the basic principle for the convergence of the circuit simulation, especially the non-convergence problems of DC analysis and transient analysis simulation, and selects the SPICE emulator as the study object. The corresponding solutions are made for the non-convergence problems according to the different causes.The circuit non-convergence problems mainly are caused by the circuit topology, the device modeling and the simulator setup. Usually the traditional research method is to modify the circuit simulation algorithm directly, the paper focuses on the improvement and optimization of the existing circuit simulation algorithm, to improve the circuit simulation convergence by considering the above three causes.The unreasonable topology can easily causes the problems about the generating of the circuit equations, the fault topology database is built to find the unreasonable topology. The device modeling mainly influences the size of the circuit equations, the target models are substituted by the corresponding XSPICE Code Models so as to reducing the size of the circuit equations and the complexity of the numerical solution.The simulator setup mainly influences the numerical algorithm of the circuit equations, the immune algorithm is adopted to find the best simulator setup, so as to improve the convergence of the circuit simulation by the simulation algorithm.In the field of the research of the circuit simulation convergence technology and the actual engineering practice, the research of the paper is important for the theory and guidance.