By Topic

Design Method for High-Order Sigma–Delta Modulator Stabilized by Departure Angles Designed to Keep Root Loci in Unit Circle

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$33 $13
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

4 Author(s)
T. -H. Kuo ; Dept. of Electr. Eng, Nat. Cheng Kung Univ., Tainan ; C. -C. Yang ; K. -D. Chen ; W. -C. Wang

In this brief, a systematic method to design stable single-stage high-order sigma-delta modulators (SDMs) without the need of stability-recovery mechanisms is proposed. It is shown that if the critical root loci of an SDM transfer function are all located inside a unit circle, then the SDM is guaranteed to be stable. Instead of basing the design on noise transfer function as in previous designs, the presented method bases the design on proper choice of open-loop transfer function departure angles so as to keep the critical root loci within the unit circle. A stable fourth-order SDM with the critical root loci inside the unit circle is given as a design example. Simulation results reveal that based on the presented design method, stable single-stage high-order SDMs can be free from overload instability even with full-scale input magnitude. Tradeoffs between stability and performance of the SDMs are presented. By allowing parts of the critical root loci to be located outside the unit circle, this method can be extended for SDM designs with higher signal-to-noise ratio but smaller stable input range

Published in:

IEEE Transactions on Circuits and Systems II: Express Briefs  (Volume:53 ,  Issue: 10 )