Simulation-based automatic generation of signomial and posynomial performance models for analog integrated circuit sizing

This paper presents a method to automatically generate posynomial response surface models for the performance parameters of analog integrated circuits. The posynomial models enable the use of efficient geometric programming techniques for circuit sizing and optimization. To avoid manual derivation of approximate symbolic equations and subsequent casting to posynomial format, techniques from design of experiments and response surface modeling in combination with SPICE simulations are used to generate signomial and posynomial models in an automatic way. Attention is paid to estimating the relative 'goodness-of-fit' of the generated models. Experimental results allow one to assess both the quality of the generated models as well as the strengths and the limitations of the presented approach.