Differential-input buffered and transconductance amplifier-based all-pass filter and its application in quadrature oscillator

This paper presents the complementary metal oxide semiconductor (CMOS) implementation of active building block, namely, current inverting differential input transconductance amplifier (CIDITA) along with its performance parameters. The detailed study of the proposed CMOS CIDITA has been incorporated. The presented study shows the good performance of CIDITA in terms of good bandwidth range, good linear range of input current, high accuracy and low operating voltage. A new circuit of single active element-based quadrature oscillator is further realized to explore the workability of CIDITA. The proposed circuit of quadrature oscillator employs two grounded capacitors, one resistor and single CIDITA. The proposed quadrature oscillator provides both quadrature current outputs and quadrature voltage outputs simultaneously. The frequency of oscillation of the proposed quadrature oscillator is electronically controllable. The possible practical realization of the CIDITA using commercially available ICs is also given. HSPICE simulation results using 0.18[Formula: see text][Formula: see text]m CMOS parameters are given to validate the proposed theory.

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Minimum Component All Pass Filters Using a New Versatile Active Element

Journal of Circuits System and Computers ◽

10.1142/s0218126620500784 ◽

2019 ◽

Vol 29 (05) ◽

pp. 2050078 ◽

Cited By ~ 1

Author(s):

Mohammad Faseehuddin ◽

Jahariah Sampe ◽

Sadia Shireen ◽

Sawal Hamid Md Ali

Keyword(s):

Integrated Circuits ◽

Fourth Order ◽

Active Element ◽

Cmos Technology ◽

Current Conveyor ◽

Experimental Results ◽

Pass Filter ◽

Differential Input ◽

Filter Structure ◽

Transconductance Amplifier

In this paper, a new active element namely Dual-X current conveyor differential input transconductance amplifier (DXCCDITA) is proposed. The DXCCDITA is utilized in designing four minimum component fully cascadable all pass filter (APF) structures. The designed all pass filters require only single active element and one/two passive elements for realization thus making them a minimum component implementation. Two among the four presented all pass structures require only a single capacitor for implementation. A scheme for realizing nth order all pass filter is also suggested and a fourth order voltage mode (VM) filter is developed from the proposed scheme. The effect of non-idealities on the proposed all pass filters is also studied. A simple oscillator is also developed using one of the all pass filter structure. The oscillator required only one DXCCDITA, two capacitors and one resistor for implementation. The DXCCDITA is implemented in 0.35[Formula: see text][Formula: see text]m TSMC CMOS technology parameters and tested in Tanner EDA. Sufficient numbers of simulations are provided to establish the functionality of all pass structures. The experimental results using commercially available integrated circuits (ICs) are also provided.

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