A technique to improve the convergency speed of relaxation-based circuit simulations on tightly coupled circuits

A technique to improve the convergency speed of relaxation-based circuit simulations is presented. This technique may overcome the difficulty of slow convergence or non-convergence characteristics of relaxation-based circuit simulation methods when the circuit contains tightly coupled components or strong feedback loops. This technique relies on the partitioning method to decompose the M matrix into r sub-circuit matrices M_ii such that the effect of tight coupling or feedback to the ith sub-circuit from the nodes outside of the sub-circuit is removed by solving zⁱ from the interconnection level matrix equation