Sigma-Delta Modulators: Tutorial Overview, Design Guide, and State-of-the-Art Survey

This paper presents a tutorial overview of $\Sigma\Delta$ modulators, their operating principles and architectures, circuit errors and models, design methods, and practical issues. A review of the state of the art on nanometer CMOS implementations is described, giving a survey of cutting-edge $\Sigma\Delta$ architectures, with emphasis on their application to the next generation of wireless telecom systems.

I. Introduction

Since the first idea underlying the operation of modulators was patented [1] and applied to implement analog-to-digital converters (ADCs) [2] around 50 years ago, there has been a huge number of circuits and systems exploiting in many different industrial applications—from instrumentation to communications [3]–[16]. Based on the combination of oversampling and quantization error shaping techniques, achieve a high degree of insensitivity to analog circuit imperfections, thus making them a good choice (the best one in many cases) to realize embedded analog-to-digital interfaces in modern systems-on-chip (SoCs) integrated in nanometer CMOS.