World Academy of Science, Engineering and Technology
Published January 2, 2015 | Version 10000339
Journal article Open

Stable Delta-Sigma Modulator with Signal Dependent Forward Path Gain for Industrial Applications

Description

Higher order ΔΣ Modulator (DSM) is basically an
unstable system. The approximate conditions for stability cannot be
used for the design of a DSM for industrial applications where risk is
involved. The existing second order, single stage, single bit, unity
feedback gain , discrete DSM cannot be used for the normalized full
range (-1 to +1) of an input signal since the DSM becomes unstable
when the input signal is above ±0.55. The stability is also not
guaranteed for input signals of amplitude less than ±0.55. In the
present paper, the above mentioned second order DSM is modified
with input signal dependent forward path gain. The proposed DSM is
suitable for industrial applications where one needs the digital
representation of the analog input signal, during each sampling
period. The proposed DSM can operate almost for the full range of
input signals (-0.95 to +0.95) without causing instability, assuming
that the second integrator output should not exceed the circuit supply
voltage, ±15 Volts.

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References

  • Richard Schreier, Gabor C. Temes, Understanding Delta-Sigma DataConverters, (IEEE Press, 2005).
  • S.R. Norsworthy, R.Schreier and G.C. Temes, Eds., Delta-Sigma Data Converters, (IEEE Press, 1997).
  • George I Bourdopoulos, Delta-Sigma Modulators Modeling, Design and Applications, (Imperial College Press, 2003).
  • S. Hein and A. Zahor, "On the stability of interpolative sigma delta modulators," IEEE Transcations on Signal Processing, Vol.41, No.7, July (1993), pp. 2322-2348.
  • Bourdopoulos G.I. "Adaptive order reduction scheme for high-order single-bit ΔΣModulators" IEEE Transactions on Circuits and Systems, Vol. 51, No. 5, pp. 213- 216,2004.
  • Maghari N., Kwon S., Temes G.C. and Moon U. "Mixed – Order Sturdy MASH Δ-Σ Modulator"IEEE International symposium on Circuits and Systems, pp. 257-260, 2007.
  • Jiaxin, Wanrong Zhang, Haolin Du, Yanfeng Jiang and YaminZhang ) "New architecture of low voltage Sigma-Delta ADC" IEEE 8th International Conference on ASIC, pp. 203-206, 2009.
  • Yavari M, Shoaei O and Rodriguez-Vazquez A "Double-sampling single-loop Sigma-Delta Modulator topologies for broad- band applications" IEEE Transactions on Circuits and Systems II, Vol.53, No.4, pp. 314-318,2007.
  • Maghari N., Temes G.C. and Moon U. "Single loop ΔΣ modulator with extended dynamic range" Electronics letters, Vol.44, No.25, pp. 1452- 1453,2008. [10] Yongsheng Wang ; Yuanhong Li ; Mingyan Yu "A 16 bit low voltage low power Delta Sigma modulator", Conference on Electronic and Mechanical Engineering and Information Technology (EMEIT), 2011 Vol. 6, Pages: 3178 – 3181. [11] Mohammadi, R. , Shamsi, H. , Abedinkhan, M., "On the designof a 2-2- 0 MASH delta-sigma-pipeline modulator", IEEE International Conference on Electronics, Circuits and Systems (ICECS), 2012 , Page(s): 348 - 351 . [12] Athar S., Siddiqi M.A. , Masud S. "Design and FPGA Implementation of a 2nd Order Adaptive delta signma modulator with One Bit Quantization", 2010 , Page(s): 388 – 393. [13] Youngjae Jung, HyungdongRoh, "An Input-Feedforward Multibit Adder-Less Modulator for Ultrasound Imaging Systems", IEEE Transactions on Instrumentation and Measurement, Vol.62, No.8, August 2013, Pages 2215-2227.