Analysis and Design of a Discrete-Time 3-0 MASH Delta-Sigma ADC With 100.2 dB Dynamic Range

This paper describes the analysis and design of a discrete-time (DT) fully dynamic 3-0 multi-stage noise-shaping (MASH) delta-sigma (<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\Delta \Sigma $ </tex-math></inline-formula>) analog-to-digital converter (ADC). Through system-level analysis, error source analysis, nonlinearity analysis and modeling of the integrators, and detailed considerations for circuit implementation, the trade-offs between design parameters in the 3-0 MASH <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\Delta \Sigma $ </tex-math></inline-formula> ADC were evaluated. The proposed ADC is fabricated and measured in a 180 nm CMOS process, achieving a DR, peak SNDR, and SFDR of 100.2 dB, 98.5 dB, and 116.7 dB, respectively, within a 2.56 kHz bandwidth, consuming only <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$20.1~\mu $ </tex-math></inline-formula>W. As a result, the Schreier figure-of-merit (FoM) for SNDR and DR are 179.6 dB and 181.3 dB, respectively. The measurement results of the prototype 3-0 MASH <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\Delta \Sigma $ </tex-math></inline-formula> ADC closely matched the theoretical predictions. This consistency between the measurements and the theoretical analysis confirms the reliability of the design approach in achieving the expected performance.