A Design Centering Algorithm for Nonconvex Regions of Acceptability

Random variations inherent in any fabrication process may result in very low production yield. This is especially true in the fabrication of integrated circuits. Several methods have been proposed to help the circuit designer minimize the influence of these random variations. Most of these methods are deterministic and try to maximize yield by centering the nominal value of the designable parameters in the so-called region of acceptability. However, these design centering techniques require an assumption of convexity which is not valid in many real design situations. To overcome this problem a new convergent method is proposed which is based on the sequential solution of subproblems for which the convexity assumption is valid. A practical implementation of the algorithm is shown by examples to be computationally efficient.