Sequence characteristics of multi-level and second-order sigma-delta modulated signals

摘要

A characteristic sequence pattern of first-order binary sigma-delta (SD) modulated signals was found recently and the pattern detectors are applied to various piecewise linear (PWL) circuits. However, practical analog-to-digital and digital-to-analog converters often employ second and higher-order SD modulations and multi-level oversampled data format. This paper presents sequence features of first-order multi-level and second-order binary SD modulated signals. In addition, the results of investigating the sequence features are applied to PWL-based nonlinear signal processing and signal measurement. The designed signal processing and measurement circuits are lower in hardware complexity than Nyquist-rate long word-length circuits of the same functions.