Sigma-Delta Systems

Graduate Student: Phil Steiner

Faculty Advisor: Woodward Yang

Sigma-Delta systems have been successfully utilized in high resolution, oversampled analog-to-digital and digital-to-analog conversion applications. Sigma-Delta (also known as Delta-Sigma) systems are essentially clocked linear feedback systems with the exception of a single nonlinearity due to a comparator (or more generally a quanatization element). In the past, analysis of Sigma-Delta systems has focussed on approximating this nonlinear system as a linear feedback system and modeling the quanatization element as an additive noise element. However, we have developed a nonlinear analysis that incorporates the full nonlinear characteristics of quanatization element. We have a closed form proof of stability of the second order sigma-delta modulator and have extended our analysis to higher order systems (see ISCAS94 paper in our technical reports).

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Jeff Miller