Advanced search
2 files | 550.74 KB Add to list

The Nyquist criterion: a useful tool for the robust design of continuous-time ΣΔ modulators

Author
Organization
Abstract
This paper introduces a figure of merit for the robustness of continuous-time sigma-delta modulators. It is based on the Nyquist criterion for the equivalent discrete-time (DT) loop filter. It is shown how continuous-time modulators can be designed by optimizing this figure of merit. This way modulators with increased robustness against variations in the noise-transfer function (NTF) parameters are obtained. This is particularly useful for constrained systems, where the system order exceeds the number of design parameters. This situation occurs for example due to the effect of excess loop delay (ELD) or finite gain bandwidth (GBW) of the opamps. Additionally, it is shown that the optimization is equivalent to the minimization of H_infinity, the maximum out-of-band gain of the NTF. This explains why conventional design strategies that are based on H_infinity, such as Schreier’s approach, provide quite robust modulator designs in the case of unconstrained architectures.
Keywords
continuous-time sigma-delta ($\Sigma\Delta$) modulation, analog-to-digital (A/D) conversion, Nyquist stability criterion, robust stability., BANDWIDTH, CMOS, COMPENSATION

Downloads

  • Nyq auteurs.pdf
    • full text
    • |
    • open access
    • |
    • PDF
    • |
    • 263.79 KB
  • (...).pdf
    • full text
    • |
    • UGent only
    • |
    • PDF
    • |
    • 286.95 KB

Citation

Please use this url to cite or link to this publication:

MLA
De Vuyst, Bart, et al. “The Nyquist Criterion: A Useful Tool for the Robust Design of Continuous-Time ΣΔ Modulators.” IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS—II: EXPRESS BRIEFS, vol. 57, no. 6, 2010, pp. 416–20, doi:10.1109/TCSII.2010.2048368.
APA
De Vuyst, B., Rombouts, P., De Maeyer, J., & Gielen, G. (2010). The Nyquist criterion: a useful tool for the robust design of continuous-time ΣΔ modulators. IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS—II: EXPRESS BRIEFS, 57(6), 416–420. https://doi.org/10.1109/TCSII.2010.2048368
Chicago author-date
De Vuyst, Bart, Pieter Rombouts, Jeroen De Maeyer, and Georges Gielen. 2010. “The Nyquist Criterion: A Useful Tool for the Robust Design of Continuous-Time ΣΔ Modulators.” IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS—II: EXPRESS BRIEFS 57 (6): 416–20. https://doi.org/10.1109/TCSII.2010.2048368.
Chicago author-date (all authors)
De Vuyst, Bart, Pieter Rombouts, Jeroen De Maeyer, and Georges Gielen. 2010. “The Nyquist Criterion: A Useful Tool for the Robust Design of Continuous-Time ΣΔ Modulators.” IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS—II: EXPRESS BRIEFS 57 (6): 416–420. doi:10.1109/TCSII.2010.2048368.
Vancouver
1.
De Vuyst B, Rombouts P, De Maeyer J, Gielen G. The Nyquist criterion: a useful tool for the robust design of continuous-time ΣΔ modulators. IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS—II: EXPRESS BRIEFS. 2010;57(6):416–20.
IEEE
[1]
B. De Vuyst, P. Rombouts, J. De Maeyer, and G. Gielen, “The Nyquist criterion: a useful tool for the robust design of continuous-time ΣΔ modulators,” IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS—II: EXPRESS BRIEFS, vol. 57, no. 6, pp. 416–420, 2010.
@article{980843,
  abstract     = {{This paper introduces a figure of merit for the robustness of continuous-time sigma-delta modulators. It is based on the Nyquist criterion for the equivalent discrete-time (DT) loop filter. It is shown how continuous-time modulators can be designed by optimizing this figure of merit. This way modulators with increased robustness against variations in the noise-transfer function (NTF) parameters are obtained. This is particularly useful for constrained systems, where the system order exceeds the number of design parameters. This situation occurs for example due to the effect of excess loop delay (ELD) or finite gain bandwidth (GBW) of the opamps. Additionally, it is shown that the optimization is equivalent to the minimization of H_infinity, the maximum out-of-band gain of the NTF. This explains why conventional design strategies that are based on H_infinity, such as Schreier’s approach, provide quite robust modulator designs in the case of unconstrained architectures.}},
  author       = {{De Vuyst, Bart and Rombouts, Pieter and De Maeyer, Jeroen and Gielen, Georges}},
  issn         = {{1549-7747}},
  journal      = {{IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS—II: EXPRESS BRIEFS}},
  keywords     = {{continuous-time sigma-delta ($\Sigma\Delta$) modulation,analog-to-digital (A/D) conversion,Nyquist stability criterion,robust stability.,BANDWIDTH,CMOS,COMPENSATION}},
  language     = {{eng}},
  number       = {{6}},
  pages        = {{416--420}},
  title        = {{The Nyquist criterion: a useful tool for the robust design of continuous-time ΣΔ modulators}},
  url          = {{http://dx.doi.org/10.1109/TCSII.2010.2048368}},
  volume       = {{57}},
  year         = {{2010}},
}

Altmetric
View in Altmetric
Web of Science
Times cited: