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Realization and Study of Current Mode Filters and Oscillators for Integrated Circuit Implementation (PhD Thesis)

By: Material type: TextTextLanguage: English Publication details: Karachi : NED University of Engineering and Technology Department of Electrical Engineering, 2003Description: 310 p. : illSubject(s): DDC classification:
  • 621.3815330378242 ABD
Summary: Abstract : This thesis presents the theory and the development of seventeen current mode novel circuits through mathematical analysis and testing using simulation techniques (based on a well known software of global fame known as PSpice). The entire work is confined to the circuits of filters and oscillators in current mode, which is the trend not only of today but also of tomorrow. Out of seventeen circuits, thirteen are filter circuits and four are oscillator circuits. The work leads to the development of new and improved filter and oscillator circuits for use in instrumentation, communication and in other areas of analogue signal processing. The circuits were designed with an aim to implement these on integrated circuits in CMOS technology. Various novel circuits based on active devices such as operational amplifiers (OAs), operational transconductance amplifiers (OTAs) with single and multiple outputs, current feedback amplifiers (CFAs) and four terminal floating nullors (FTFNs) have been developed and studied for their characteristics. The salient features of each of the developed circuits are described. The methodology has been to conceive a circuit topology, develop its mathematical model in the form of current mode transfer function and then simulate it using PSpice. The performance of each circuit has been validated by comparing the responses obtained using simulation with the results predicted by theory. Sensitivity analysis is also carried out for every circuit and it was observed that the absolute values of sensitivities are less than or equal to 1. In some filter applications, multiple output OTAs are used which enable the implementation of universal filters with minimum components. Novel Active only filter circuits, with no external passive element, have also been designed and evaluated. Majority of the circuits designed in this project are based on biquad, which is considered to be the most effective approach in filter design and has been used extensively by various investigators. Electronic tunability is one of the major features of some of the designs. Use of grounded capacitors makes the designs suitable for integrated circuits development in CMOS technology. Keywords: Active Filter, Quadrature Oscillator, Current-mode Circuit, Operational Amplifier, Operational Transconductance Amplifier, Current Feedback Amplifier, Current Conveyor, Four Terminal Floating Nullor, Active Only Filter, Negative Capacitor, Sensitivity.
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Item type Current library Shelving location Call number Status Date due Barcode
Reference Collection Reference Collection Government Document Section Govt Publication Section 621.3815330378242 ABD Available 69134
Reference Collection Reference Collection Government Document Section Govt Publication Section 621.3815330378242 ABD Available 69135

Abstract :

This thesis presents the theory and the development of seventeen current mode novel circuits through mathematical analysis and testing using simulation techniques (based on a well known software of global fame known as PSpice). The entire work is confined to the circuits of filters and oscillators in current mode, which is the trend not only of today but also of tomorrow. Out of seventeen circuits, thirteen are filter circuits and four are oscillator circuits. The work leads to the development of new and improved filter and oscillator circuits for use in instrumentation, communication and in other areas of analogue signal processing. The circuits were designed with an aim to implement these on integrated circuits in CMOS technology.
Various novel circuits based on active devices such as operational amplifiers (OAs), operational transconductance amplifiers (OTAs) with single and multiple outputs, current feedback amplifiers (CFAs) and four terminal floating nullors (FTFNs) have been developed and studied for their characteristics. The salient features of each of the developed circuits are described.
The methodology has been to conceive a circuit topology, develop its mathematical model in the form of current mode transfer function and then simulate it using PSpice. The performance of each circuit has been validated by comparing the responses obtained using simulation with the results predicted by theory. Sensitivity analysis is also carried out for every circuit and it was observed that the absolute values of sensitivities are less than or equal to 1.
In some filter applications, multiple output OTAs are used which enable the implementation of universal filters with minimum components. Novel Active only filter circuits, with no external passive element, have also been designed and evaluated.
Majority of the circuits designed in this project are based on biquad, which is considered to be the most effective approach in filter design and has been used extensively by various investigators. Electronic tunability is one of the major features of some of the designs. Use of grounded capacitors makes the designs suitable for integrated circuits development in CMOS technology.
Keywords: Active Filter, Quadrature Oscillator, Current-mode Circuit, Operational Amplifier, Operational Transconductance Amplifier, Current Feedback Amplifier, Current Conveyor, Four Terminal Floating Nullor, Active Only Filter, Negative Capacitor, Sensitivity.