Hong-wei Ma
ABSTRACT
The intrinsic anti-aliasing characteristic is one of the remarkable advantages of Continuous Time Signa Delta Modulator (CTΣΔM) over its DT counterpart, whereas few stringently mathematical demonstrations have been discovered in prior literatures especially from the point view of time domain. To begin with, based on frequency domain, the STF and anti-alias filtering function of the equivalent DT counterpart resulting from the impulse invariant transformation (IIT) method are extracted from the CTΣΔM STF. Then in time domain, its response function to input signal is obtained according to the relationship between the charging, discharging of active RC integrator during each sampling time interval and the top half, bottom half integral of convolution for first, second order CTΣΔM, respectively. Furthermore, employing the principle of charge conservation, the transfer function of the discrete time path from output of the loop filter to that of the modulator is reached, and hence the general mix-time signal STF. Finally, the anti-alias filtering function is extracted. By comparison, the anti-alias filtering properties match very well resulted from analysis of frequency and time domain, respectively.
- Shoaei Omid, 1995. Continuous-time delta-sigma A/D converters for high speed applications, PhD Thesis, Carleton University.Google Scholar
- Richard Schreier, Boming Zhang, 1996. Delta-sigma modulators employing continuous-time circuitry, IEEE Transactions on Circuits and Systems I Fundamental Theory and Applications 43(4):324--332. May 1996Google ScholarCross Ref
- Dr.-Ing Maurits Ortmanns, Dr. Friedel Gerfers, 2006. Continuous time sigma-delta A/D conversion fundamentals, performance limits and robust implementations, Springer, Berlin, Heidelberg.Google Scholar
- Jose M. de la Rosa, Rocio del Rio, 2013. CMOS sigma-delta converters, Practical Design Guide, Wiley-IEEE Press, New York.Google Scholar
- Cherry, J.A., Snelgrove, W.M., 1999, Continuous-time delta-sigma modulators for high-speed A/D conversion, Kluwer Academic Publisher, Dordrecht. Google ScholarDigital Library
- Candy, J.C., 1985. A use of double integration in sigma-delta modulation, IEEE Trans. Commun. 33, 249--25.Google ScholarCross Ref
- Alan V. Oppenheim, Alan S. Willsky, S. Hamid, 1996. Signals and systems, Pearson, New York.Google Scholar
- Medeiro, F., Perez-Verdu, B., Rodriguez-Vazquez A., 1999. Top-down design of high-performance sigma-delta modulators, Kluwer Academic Publisher, Dordrecht.Google Scholar
- Richard Schreier, Gabor C. Temes, 2004. Understanding delta-sigma data converters, Wiley-IEEE Press, New York.Google Scholar
Index Terms
- An Analysis of the Anti-aliasing Property of Continuous Time ΣΔ Modulators from perspective of Time Domain
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