A performance-constrained template-based layout retargeting algorithm for analog integrated circuits

Performance of analog integrated circuits is highly sensitive to layout parasitics. This paper presents an improved template-based algorithm that automatically conducts performance-constrained parasitic-aware retargeting and optimization of analog layouts. In order to achieve desired circuit performance, performance sensitivities with respect to layout parasitics are first determined. Then the algorithm applies a piecewise-sensitivity model to control parasitic-related layout geometries by directly constructing a set of performance constraints subject to maximum performance deviation due to parasitics. The formulated problem is finally solved using graph-based techniques combined with mixed-integer nonlinear programming. The proposed method has been incorporated into a parasitic-aware automatic layout optimization and retargeting tool. It has been demonstrated to be effective and efficient especially when adapting layout design for new technologies or updated specifications.