Constraint Symbolization Method for Analog Layout Retargeting with Geometric Programming

To satisfy the requirements of complex and special analog layout constraints, a constraint symbolization method based on geometric programming for analog layout retargeting is presented in this paper. Our approach is to build symbolic template for layouts, then uses Geometric programming (GP) to achieve new technology design rules, implement device symmetry and matching constraints, and manage parasitics optimization. The GP, a class of nonlinear optimization problem, can be transferred or fitted into a convex optimization problem. Therefore, a global optimum solution can be achieved. The symbolization method ensures the layout retargeting automatically. The efficiency and effectiveness of the proposed algorithm, as compared with the other existing methods, are demonstrated by a basic case-study example and a two-stage Miller-compensated operational amplifier.