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Review
. 2013 Jan;4(1):1-11.
doi: 10.1016/j.jare.2012.03.001. Epub 2012 Apr 18.

Two integrator loop quadrature oscillators: A review

Ahmed M Soliman  1
Affiliations
Review

Two integrator loop quadrature oscillators: A review

Ahmed M Soliman. J Adv Res. 2013 Jan.

Abstract

A review of the two integrator loop oscillator circuits providing two quadrature sinusoidal output voltages is given. All the circuits considered employ the minimum number of capacitors namely two except one circuit which uses three capacitors. The circuits considered are classified to four different classes. The first class includes floating capacitors and floating resistors and the active building blocks realizing these circuits are the Op Amp or the OTRA. The second class employs grounded capacitors and includes floating resistors and the active building blocks realizing these circuits are the DCVC or the unity gain cells or the CFOA. The third class employs grounded capacitors and grounded resistors and the active building blocks realizing these circuits are the CCII. The fourth class employs grounded capacitors and no resistors and the active building blocks realizing these circuits are the TA. Transformation methods showing the generation of different classes from each other is given in details and this is one of the main objectives of this paper.

Keywords: Current conveyor; Current feedback operational amplifier; Op Amp; Operational transresistance amplifier; Two integrator loop oscillators; Unity gain cells.

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Figures

Fig. 1a
Fig. 1a
Three Op Amp oscillator circuit [1–4].
Fig. 1b
Fig. 1b
Modified three Op Amp oscillator circuit .
Fig. 1c
Fig. 1c
Three Op Amp oscillator circuit .
Fig. 1d
Fig. 1d
Two Op Amp oscillator circuit .
Fig. 2a
Fig. 2a
Two OTRA oscillator circuit I .
Fig. 2b
Fig. 2b
Two OTRA oscillator circuit II .
Fig. 3a
Fig. 3a
Two DCVC oscillator circuit I .
Fig. 3b
Fig. 3b
Two DCVC oscillator circuit II .
Fig. 4a
Fig. 4a
Unity gain cells oscillator circuit equivalent to Fig. 3a .
Fig. 4b
Fig. 4b
Unity gain cells oscillator circuit equivalent to Fig. 3b .
Fig. 5a
Fig. 5a
Two CFOA grounded capacitor oscillator circuit I [23–25].
Fig. 5b
Fig. 5b
Two CFOA grounded capacitor oscillator circuit II .
Fig. 6a
Fig. 6a
Three CCII oscillator circuit I .
Fig. 6b
Fig. 6b
Three CCII oscillator circuit II .
Fig. 7a
Fig. 7a
Grounded passive elements oscillator circuit I .
Fig. 7b
Fig. 7b
Grounded passive elements oscillator circuit II .
Fig. 8a
Fig. 8a
Single output CCII equivalent circuit to Fig. 7a .
Fig. 8b
Fig. 8b
Single output CCII equivalent circuit to Fig. 7b. .
Fig. 9a
Fig. 9a
Four TA grounded capacitors oscillator generated from Fig. 6a.
Fig. 9b
Fig. 9b
Four TA grounded capacitors oscillator generated from Fig. 6b.
Fig. 10a
Fig. 10a
Three TA oscillator circuit I.
Fig. 10b
Fig. 10b
Three TA oscillator circuit II.
Fig. 11
Fig. 11
Three TA oscillator with one two input TA [42–44].
See this image and copyright information in PMC

References

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    1. Budak A. Houghton Mifflin Company; 1974. Passive and active network analysis and synthesis. p. 458–85.
    1. Anderson B.D.O. Oscillator design problem. IEEE J Solid-State Circuits. 1971;6:89–91.
    1. Soliman A.M. Transformation of oscillators using Op Amps, unity gain cells and CFOA. Analog Integr Circ S. 2010;65:105–114.

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