A Robust Exponential Integrator Method for Generic Nonlinear Circuit Simulation

In this paper, we aim to address two long-lasting issues in large scale transient circuit simulation using the exponential integrator (EI) method. First is the numerical instability caused by the singularity in the differential-algebraic equation system. Our proposed solution is a systematic, algebraic and sparsity preserving regularization technique to eliminate the unstable modes in the system to be solved. Next, we devise a generic scheme to apply Newton-Raphson iterations in the EI framework for enhanced nonlinearity handling capability. With the two techniques, we wish to elevate the robustness and performance of EI and make it a competitive alternative to the existing SPICE-type simulators in practical usage.