Current Feedback Operational Amplifiers And Current Conveyors; An Overview And Recent Developments

2005 ◽  
Author(s):  
O. Cicekoglu
Keyword(s):  
Operational Amplifiers ◽  
Current Conveyors ◽  
Current Feedback ◽  
Current Feedback Operational Amplifiers ◽  
Recent Developments

ACTIVE CIRCULATOR CIRCUITS USING OA, CCII, CFOA AND DVCC

2009 ◽  
Vol 18 (04) ◽  
pp. 629-645 ◽  
Author(s):  
AHMED M. SOLIMAN
Keyword(s):  
Detailed Comparison ◽  
Current Conveyor ◽  
Operational Amplifiers ◽  
Current Conveyors ◽  
Spice Simulation ◽  
Current Feedback ◽  
Current Feedback Operational Amplifiers ◽  
Different Types ◽  
Simulation Results ◽  
Differential Voltage Current Conveyor

A review of the two types of circulators using Operational Amplifiers (OA) with detailed comparison is given. Novel active circulator circuits using Current Conveyors (CCII) and Current Feedback Operational Amplifiers (CFOA) and Differential Voltage Current Conveyor (DVCC) are introduced. The proposed CCII circulator circuit uses six CCIIs and three floating resistors. Two different circulator types using the CFOA are given. A circulator circuit which uses three DVCCs and has the advantage of using three grounded resistors is also introduced. Spice simulation results using 0.5 μm CMOS transistors are included to support the theoretical analysis and demonstrate comparisons among the different types of circulators.

scholarly journals Comparative Study of Discrete Component Realizations of Fractional-Order Capacitor and Inductor Active Emulators

2018 ◽  
Vol 27 (11) ◽  
pp. 1850170 ◽  
Author(s):  
Georgia Tsirimokou ◽  
Aslihan Kartci ◽  
Jaroslav Koton ◽  
Norbert Herencsar ◽  
Costas Psychalinos
Keyword(s):  
Comparative Study ◽  
Fractional Order ◽  
High Performance ◽  
Continued Fraction ◽  
Transfer Functions ◽  
Operational Amplifiers ◽  
Current Conveyors ◽  
Continued Fraction Expansion ◽  
Current Feedback ◽  
Discrete Component

Due to the absence of commercially available fractional-order capacitors and inductors, their implementation can be performed using fractional-order differentiators and integrators, respectively, combined with a voltage-to-current conversion stage. The transfer function of fractional-order differentiators and integrators can be approximated through the utilization of appropriate integer-order transfer functions. In order to achieve that, the Continued Fraction Expansion as well as the Oustaloup’s approximations can be utilized. The accuracy, in terms of magnitude and phase response, of transfer functions of differentiators/integrators derived through the employment of the aforementioned approximations, is very important factor for achieving high performance approximation of the fractional-order elements. A comparative study of the accuracy offered by the Continued Fraction Expansion and the Oustaloup’s approximation is performed in this paper. As a next step, the corresponding implementations of the emulators of the fractional-order elements, derived using fundamental active cells such as operational amplifiers, operational transconductance amplifiers, current conveyors, and current feedback operational amplifiers realized in commercially available discrete-component IC form, are compared in terms of the most important performance characteristics. The most suitable of them are further compared using the OrCAD PSpice software.

VARIOUS CURRENT-MODE AND VOLTAGE-MODE INSTRUMENTATION AMPLIFIER TOPOLOGIES SUITABLE FOR INTEGRATION

2010 ◽  
Vol 19 (03) ◽  
pp. 689-699 ◽  
Author(s):  
ERKAN YUCE
Keyword(s):  
Integrated Circuit ◽  
Experimental Tests ◽  
Current Mode ◽  
The Other ◽  
Operational Amplifiers ◽  
Instrumentation Amplifier ◽  
Nmos Transistor ◽  
Current Feedback ◽  
Voltage Mode ◽  
Current Feedback Operational Amplifiers

In this paper, four instrumentation amplifier (IA) topologies, one of which is current-mode (CM) while the others are voltage-mode (VM), are presented. Three of the IAs use one to two current feedback operational amplifiers (CFOAs) while the other one employs only a single NMOS transistor. One of the IA circuits, given as an example, is simple while others are novel. The CM IA is composed of only grounded resistors which have some advantages in integrated circuit (IC) process. Non-ideality effects such as non-ideal gain and parasitic impedances on the performance of introduced IAs are discussed. In order to show the performance of the circuits, we perform experimental tests and simulations by using SPICE program.

scholarly journals CFOA-Based New Structure of Fractional Order Inverse Filters

2020 ◽  
Vol 8 (5) ◽  
pp. 4501-4504
Keyword(s):  
Stability Analysis ◽  
Fractional Order ◽  
Operational Amplifiers ◽  
Inverse Filter ◽  
Current Feedback ◽  
Current Feedback Operational Amplifiers ◽  
Low Pass ◽  
Band Pass ◽  
High Pass

This paper presents a CFOA-based fractional order inverse filter (FOIF) structure. Proposed structure utilizes two current feedback operational amplifiers (CFOAs), two fractional capacitors (FCs) and two resistors to design FOIFs to realize fractional order inverse low pass (FOILP), fractional order inverse high pass (FOIHP) and fractional order inverse band pass (FOIBP) responses. The proposed configuration of FOIFs is simulated in PSPICE using AD844 type CFOAs. Stability analysis and MATLAB simulations are also carried out to authenticate the theoretical propositions.

A nonlinear macromodel for current-feedback operational amplifiers

2015 ◽  
Vol 46 (10) ◽  
pp. 941-949 ◽  
Author(s):  
E. Ortega-Torres ◽  
S. Ruíz-Hernández ◽  
C. Sánchez-López
Keyword(s):  
Operational Amplifiers ◽  
Current Feedback ◽  
Current Feedback Operational Amplifiers

Experimental Verification of Fractional-Order Filters Using a Reconfigurable Fractional-Order Impedance Emulator

2017 ◽  
Vol 26 (09) ◽  
pp. 1750142 ◽  
Author(s):  
Ilias Dimeas ◽  
Georgia Tsirimokou ◽  
Costas Psychalinos ◽  
Ahmed S. Elwakil
Keyword(s):  
Fractional Order ◽  
Filter Design ◽  
Point Of View ◽  
Operational Amplifiers ◽  
Current Feedback ◽  
Time Constants ◽  
Design Flexibility ◽  
Important Benefit ◽  
Current Feedback Operational Amplifiers ◽  
Selection Of

Fractional-order filter design examples, realized through the substitution of fractional-order capacitors and inductors by a re-configurable active emulator, are presented in this paper. The implementation of the emulator is achieved using Current Feedback Operational Amplifiers (CFOAs) as active elements with the required fractional-order differentiation/integration performed through the employment of an integer-order multi-feedback topology. An important benefit, from the design flexibility point of view, is that the same topology could be re-configured for emulating both fractional-order capacitors and inductors through the appropriate selection of the time-constants and gain factors. The behavior of the realized filters is experimentally evaluated using commercially available CFOAs.

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