Context-dependent transformation of Pareto-optimal performance fronts of operational amplifiers

Abstract

The use of Pareto-optimal performance fronts in emerging design methodologies for analog integrated circuits is a keystone to overcome the limitations of traditional design methodologies. However, most techniques to generate the fronts reported so far neglect the effect that the surrounding circuitry (such as the load impedance) has on the Pareto-front, thereby making it only realistic for the context where the front was generated. This strongly limits the use of the Pareto front because of the strong dependence between the key performances of an analog circuit and its surrounding circuitry, but, more importantly, because this circuitry remains unknown until the Pareto-optimal front is being used. Since performance front generation is a costly process, this paper proposes that performance fronts for a new context of use of a given circuit can be obtained from fronts that were previously generated under some different conditions. Towards this goal, a transformation methodology for performance objectives of operational amplifiers has been developed. Experimental results for a folded-cascode and a Miller-compensated operational amplifiers show that this is a promising approach to reuse the fronts in multiple contexts.