Abstract
This comment is related to the recently published article entitled “On ‘Discussion on Barkhausen and Nyquist stability criteria’, Analog Integrated circuits and signal processing, Vol. 70, pp. 443–449, 2012. In this article the authors considered one of the possible four alternatives of the Wien-bridge oscillator that was previously considered in the article entitled “Discussion on Barkhausen and Nyquist stability criteria”, Analog Integrated Circuits and Signal Processing, Vol. 62, pp. 327–332, 2010, which depicts the failure of Barkhausen criterion concerning the determination of the condition of oscillation startup of sinusoidal oscillation. In the above mentioned articles the operational amplifier used is assumed ideal. In this comment it will be shown that the Wien-bridge oscillator circuit used in the above mentioned articles can behave as a sinusoidal oscillator only at relatively high frequencies when the operational amplifier can be considered non-ideal. At relatively low frequencies; when the operational amplifier can be considered ideal, the same circuit behaves as a relaxation oscillator with a square wave output rather than a sinusoidal output.
References
Singh, V. (2007). Failure of Barkhausen oscillation building up criterion: Further evidence. Analog Integrated Circuits and Signal Processing, 50, 127–132.
Singh, V. (2010). Discussion on Barkhausen and Nyquist stability criteria. Analog Integrated Circuits and Signal Processing, 62, 327–332.
Martinez-Garcia, H., Grau-Slades, A., Bolea-Monte Y., & Gamiz-Caro, J. (2012) On Discussion on Barkhausen and Nyquist stability criteria, Analog Integrated Circuits and Signal Processing, 70, 443–449.
Sedra, A., & Smith, K. C. (1998). Microelectronics circuits, chapt 12 (4th ed.). New York: Oxford University Press.
Abuelma’atti, M. T., Buhalim, S. S., & Alzaher, H. A. (1995). A novel single-capacitor single-operational-amplifier sinusoidal oscillator. IEEE Transactions on Education, 38, 391–393.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Abuelma’atti, M.T., Khalifa, Z.J. Comment on ‘Discussion on Barkhausen and Nyquist stability criteria’. Analog Integr Circ Sig Process 73, 989–992 (2012). https://doi.org/10.1007/s10470-012-9907-7
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10470-012-9907-7