Design considerations on very high resolution sigma-delta modulators

This paper describes theoretical limits and practical considerations concerning the design of high resolution (SNR>100 dB) sigma-delta A/D converters. By looking at a series of constraints affecting the design of basic devices and building blocks, we discuss important aspects of the theory of high-order single-loop modulators and find limitations to the maximum signal-to-noise ratio as a function of the power consumption and the sampling frequency. Moreover, starting from the theoretical results, we show how to optimize the modulator performance with behavioral simulations.