Implementation and performance evaluation of sigma-delta modulators

Abstract

SigmaDelta A/D converters have recently become popular since they achieve high resolution by means of oversampling without the need of high accuracy matching of elements and complex analog circuitry. They even reach higher performance utilizing feedback and feedforward paths. However finding the paths to be used and their values in an optimal way is an important concern, since there exist a lot of paths. In search of optimality, this work starts with the realization of the topologies found by an automation tool. Then, some theoretical approach about the performance of the architectures are developed. Following this, using either implementation data or theoretical approach it searches for finding closedform equations relating performance with path gains. Defining SNR sensitivity, area and power consumption as performance metrics, it reaches some relations which are functions of path gains.