Circuit performance variability reduction: principles, problems, and practical solutions

The authors present several novel results in the area of variability minimization. They develop a variability gradient formula, give the theoretical conditions for variability minimization, and outline the principles and practical solutions of factor screening for variability. A multistage procedure is described for on-target design, based on variability gradient information, dynamic screening, performance variance minimization, and separate on-target tuning. This methodology was successfully applied to the variability minimization of a practical CMOS delay circuit, after several direct methods of on-target oriented methods failed.<>