Call for Paper

CAE solicits original research papers for the October 2021 Edition. Last date of manuscript submission is September 30, 2021.

Read More

A Novel High Input Impedance AC-Coupled Buffer

Emad Alnasser. Published in Circuits and Systems.

Communications on Applied Electronics
Year of Publication: 2016
Publisher: Foundation of Computer Science (FCS), NY, USA
Authors: Emad Alnasser
10.5120/cae2016652278

Emad Alnasser. A Novel High Input Impedance AC-Coupled Buffer. Communications on Applied Electronics 5(4):17-22, June 2016. BibTeX

@article{10.5120/cae2016652278,
	author = {Emad Alnasser},
	title = {A Novel High Input Impedance AC-Coupled Buffer},
	journal = {Communications on Applied Electronics},
	issue_date = {June 2016},
	volume = {5},
	number = {4},
	month = {Jun},
	year = {2016},
	issn = {2394-4714},
	pages = {17-22},
	numpages = {6},
	url = {http://www.caeaccess.org/archives/volume5/number4/611-2016652278},
	doi = {10.5120/cae2016652278},
	publisher = {Foundation of Computer Science (FCS), NY, USA},
	address = {New York, USA}
}

Abstract

Designing an AC-coupled buffer that works in the extremely low frequency range, a few Hertz, when the coupling capacitor is very small, a few pico-farads, forms a complex designing problem. In this article, a novel and simple scheme is proposed to realize such an AC-coupled buffer.

The proposed buffer shows extremely high input impedance at the low frequencies. This feature enables the proposed buffer to capture extremely low frequency signals which is coupled to it through a very small capacitor.

The main advantage of the proposed method is that, it can be implemented on a chip or by using general purpose discrete electronic components very easily.

The characteristics of the proposed buffer have been obtained and measured experimentally, analytically and, by using a computer aided design software.

References

  1. Enrique Spinelli, and Marcelo Haberman. 2010. Insulating electrodes: a review on biopotential front ends for dielectric skin–electrode interfaces. Physiol. Meas. (31), 183-198.
  2. Yong Gyu Lim, Ko Keun Kim, and Kwang Suk Park. 2006. ECG Measurement on a Chair Without Conductive Contact. IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING 53 (5), 956-959.
  3. Yong Gyu Lim, Ko Keun Kim, and Kwang Suk Park. 2007. ECG Recording on a Bed During Sleep Without Direct Skin-Contact. IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING 54 ( 4) 718-725.
  4. Thomas J. Sullivan, Stephen R. Deiss, and Gert Cauwenberghs. (Nov. 2007). A Low-Noise, Non-Contact EEG/ECG Sensor. IEEE Biomedical Circuits and Systems Conference, 154-157.
  5. GuoChen Peng, Zeljko Ignjatovic, and Mark F. Bocko. ( July 2013). Preamplifiers for non-contact capacitive biopotential measurements. Annual International Conference of the IEEE EMBS, 1482 – 1485.
  6. Ramon Pallas-Areny, Josep Colominas, and Javier Rosell. (1989). An Improved Buff er for Bioelectric Signals", IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING 36( 4), 490-493.
  7. Antoniou A. . 1969. Realisation of gyratqrs using operational amplifiers, and their use in RC-active-network synthesis. Proceedings of the Institution of Electrical Engineers 116 (11), 1838 – 1850.
  8. PAUL R. GRAY, PAUL J. HURST, STEPHEN H. LEWIS, and ROBERT G. MEYER. 2009. Analysis and design of analog integrated circuits, 5th edition, Wiley.
  9. Analog Devices Inc., “Op-Amp noise”, [online], http://www.analog.com/media/en/training-seminars/tutorials/MT-047.pdf

Keywords

AC-coupled buffer, impedance, frequency response, noise, generalized impedance converter