Design and Performance Analysis of a Sigma-Delta Modulator

Analog and digital signals are essential concepts in contemporary electrical engineering. Analog signals are primarily disadvantaged by their inherent susceptibility to noise and distortion, which degrade signal quality during transmission and processing. This vulnerability necessitates their conversion into a more robust digital form before computation and secure storage. This critical conversion is executed by an Analog-to-Digital Converter (ADC). An ADC samples a continuous analog input, typically a voltage or current, and encodes it as a discrete, multi-bit digital value. The precision of this digital output is determined by the resolution of the ADC, which is based on the number of bits used during the conversion process. This project focuses on the design and testing of a sigma-delta analog-to-digital converter. It will analyze the function of each component within the system, detail the testing methods employed, and present the results from both individual component tests and the overall system performance. Sigma-delta converters have gained popularity as an ADC architecture due to their relatively simple design and capability to deliver high-resolution, low-noise conversions. By designing and simulating a basic sigma-delta converter, this project explores key concepts in integrated circuit design, signal processing, and ADC functionality. For an OSR of 512, we obtained a SINAD of 69.78 dB and an ENOB of 11.3.