RLCSYN: RLC Equivalent Circuit Synthesis for Structure-Preserved Reduced-order Model of Interconnect

This paper aims to explore RLC equivalent circuit synthesis method for reduced-order models of interconnect circuits obtained by Krylov subspace based model order reduction (MOR) methods. To guarantee pure RLC equivalent circuits can be synthesized for the reduced-order models, both the structures of input and output incidence matrices and the block structure of the circuit matrices should be preserved in the reduced-order models. Block structure preserving MOR methods such as SPRIM (Freund, 2004) and SAPOR (Su et al., 2004) have been well established. In this paper, an embeddable input-output structure preserving order reduction (IOPOR) technique was proposed to further preserve the structures of input and output incidence matrices in the reduced-order models. By combining block structure preserving MOR methods and IOPOR technique, an RLC equivalent circuit synthesis method RLCSYN (RLC SYNthesis) was developed. Inline diagonalization and regularization techniques are specifically proposed to enhance the robustness of inductance synthesis. The pure RLC model, high modeling accuracy, passivity guaranteed property and SPICE simulation robustness make RLCSYN more applicable in interconnect analysis, either for digital IC design or mixed signal IC simulation.