Accurate metamodels of device parameters and their applications in performance modeling and optimization of analog integrated circuits

Techniques for constructing metamodels of device parameters at BSIM3v3 level accuracy are presented to improve knowledge-based circuit sizing optimization.Based on the analysis of the prediction error of analytical performance expressions,operating point driven (OPD) metamodels of MOSFETs are introduced to capture the circuit’s characteristics precisely.In the algorithm of metamodel construction,radial basis functions are adopted to interpolate the scattered multivariate data obtained from a well tailored data sampling scheme designed for MOSFETs.The OPD metamodels can be used to automatically bias the circuit at a specific DC operating point.Analytical-based performance expressions composed by the OPD metamodels show obvious improvement for most small-signal performances compared with simulation-based models.Both operating-point variables and transistor dimensions can be optimized in our nesting-loop optimization formulation to maximize design flexibility.The method is successfully applied to a low-voltage low-power amplifier.