scholarly journals Realisations of single-resistance-controlled quadrature oscillators using a generalised current follower transconductance amplifier and a unity-gain voltage-follower

2010 ◽  
Vol 97 (8) ◽  
pp. 897-906 ◽  
Author(s):  
Norbert Herencsár ◽  
Kamil Vrba ◽  
Jaroslav Koton ◽  
Abhirup Lahiri
Keyword(s):  
Transconductance Amplifier ◽  
Current Follower ◽  
Voltage Follower ◽  
Unity Gain ◽  
Quadrature Oscillators

Dual-Mode Quadrature Oscillator Using Current Follower Transconductance Amplifiers for GMI Sensors

2013 ◽  
Vol 712-715 ◽  
pp. 1886-1890
Author(s):  
Lei Zhang ◽  
Zhong Ming Pan
Keyword(s):  
Dual Mode ◽  
Transconductance Amplifier ◽  
Current Voltage ◽  
Sinusoidal Oscillator ◽  
Current Follower ◽  
Condition Of Oscillation ◽  
Transconductance Amplifiers ◽  
Passive Sensitivity ◽  
Quadrature Oscillators ◽  
Circuit Configuration

For designing GMI sensors, realization of current/voltage-mode (dual-mode) quadrature sinusoidal oscillator with the employment of current follower transconductance amplifier (CFTA) as the active component is presented. The proposed circuit configuration comprising two CFTAs, one grounded resistor and two grounded capacitors can simultaneously provide two explicit quadrature output currents and two quadrature output voltages. Moreover, the proposed circuit topology enjoys the advantage of independent control of the condition of oscillation and frequency of oscillation and good active and passive sensitivity performances. The functionality of the proposed quadrature oscillators has been verified by PSPICE simulations.

scholarly journals New Current-Mode Oscillators Using a Single Unity-Gain Current-Follower

1995 ◽  
Vol 18 (3) ◽  
pp. 151-157 ◽  
Author(s):  
Muhammad Taher Abuelma'atti
Keyword(s):  
Current Mode ◽  
Quadrature Oscillator ◽  
Current Follower ◽  
Unity Gain ◽  
Simulation Results

A general circuit for realizing current-mode oscillators using a single negative unity-gain current-follower is presented. Using this circuit new oscillators of this class can be discovered systematically. Simulation results obtained from three new circuits are presented. The feasibility of obtaining a quadrature oscillator is investigated.

scholarly journals Gm-Realization of Controlled-Gain Current Follower Transconductance Amplifier

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Worapong Tangsrirat
Keyword(s):  
Current Mode ◽  
Cmos Technology ◽  
Current Transfer ◽  
Biquad Filter ◽  
Transconductance Amplifier ◽  
Current Follower ◽  
Dc Bias ◽  
Simulation Results ◽  
Supply Voltages ◽  
A Current

This paper describes the conception of the current follower transconductance amplifier (CFTA) with electronically and linearly current tunable. The newly modified element is realized based on the use of transconductance cells (Gms) as core circuits. The advantage of this element is that the current transfer ratios (iz/ipandix/iz) can be tuned electronically and linearly by adjusting external DC bias currents. The circuit is designed and analyzed in 0.35 μm TSMC CMOS technology. Simulation results for the circuit with ±1.25 V supply voltages show that it consumes only 0.43 mw quiescent power with 70 MHz bandwidth. As an application example, a current-mode KHN biquad filter is designed and simulated.

Design of High Gain Folded Cascode OTA-Based Transconductance–Capacitance Loop Filter for PLL Applications

2021 ◽  
pp. 2150263
Author(s):  
Priti Gupta ◽  
Sanjay Kumar Jana
Keyword(s):  
Power Consumption ◽  
Supply Voltage ◽  
High Gain ◽  
Cmos Process ◽  
Operational Transconductance Amplifier ◽  
Loop Filter ◽  
Transconductance Amplifier ◽  
Dc Gain ◽  
Unity Gain ◽  
Folded Cascode

This paper deals with the designing of low-power transconductance–capacitance-based loop filter. The folded cascode-based operational transconductance amplifier (OTA) is designed in this paper with the help of quasi-floating bulk MOSFET that achieved the DC gain of 88.61[Formula: see text]dB, unity gain frequency of 97.86[Formula: see text]MHz and power consumption of 430.62[Formula: see text][Formula: see text]W. The proposed OTA is compared with the exiting OTA structure which showed 19.50% increase in DC gain and 15.11% reduction in power consumption. Further, the proposed OTA is used for the designing of transconductance–capacitance-based loop filter that has been operated at [Formula: see text]3[Formula: see text]dB cut-off frequency of 30.12[Formula: see text]MHz with the power consumption of 860.90[Formula: see text][Formula: see text]W at the supply voltage of [Formula: see text][Formula: see text]V. The transistor-level simulation has been done in 0.18[Formula: see text][Formula: see text]m CMOS process.

scholarly journals First–Order Transfer Sections with Reconnection–Less Electronically Reconfigurable High–Pass, All–Pass and Direct Transfer Character

2016 ◽  
Vol 67 (1) ◽  
pp. 12-20 ◽  
Author(s):  
Roman Sotner ◽  
Jan Jerabek ◽  
Norbert Herencsar ◽  
Roman Prokop ◽  
Abhirup Lahiri ◽  
...  
Keyword(s):  
Transfer Functions ◽  
Current Gain ◽  
Direct Transfer ◽  
First Order ◽  
Output Terminal ◽  
Active Elements ◽  
Transconductance Amplifier ◽  
Current Follower ◽  
Active Filtering ◽  
High Pass

Abstract Presented research introduces active filtering circuits which allow change of the transfer type without necessity of reconnection of the input or output terminal that can be very useful for on-chip applications. Our attention is focused on simple first-order filters that allow high-pass response (HP), all-pass response (AP) and also direct transfer (DT) with constant magnitude and phase characteristics between two terminals (input and output) by adjusting of one controllable parameter (current gain B in our case). Useful modification of the well-known current follower transconductance amplifier (CFTA), the so-called Z-copy current-controlled current follower differential input transconductance amplifier (ZC-CCCFDITA) and adjustable current amplifier were utilized in these circuits. Interesting possibilities (crossing between several transfer functions) of presented circuits require different values of B to obtain desired transfer function that is very important for practice and selection of specific way of control. Requirements on value of this continuously controllable gain B differ among presented structures. Theory is supported by simulation and measurement results with behavioral models utilizing commercially available active elements and simulation results with active elements based on CMOS models.

scholarly journals Multiobjective Genetic Algorithms Program for the Optimization of an OTA for Front-End Electronics

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Abdelghani Dendouga ◽  
Slimane Oussalah ◽  
Damien Thienpont ◽  
Abdenour Lounis
Keyword(s):  
Genetic Algorithms ◽  
Complementary Metal Oxide Semiconductor ◽  
Cmos Technology ◽  
Oxide Semiconductor ◽  
Program Optimization ◽  
Circuit Simulator ◽  
Multiobjective Genetic Algorithms ◽  
Transconductance Amplifier ◽  
Analog Part ◽  
Unity Gain

The design of an interface to a specific sensor induces costs and design time mainly related to the analog part. So to reduce these costs, it should have been standardized like digital electronics. The aim of the present work is the elaboration of a method based on multiobjectives genetic algorithms (MOGAs) to allow automated synthesis of analog and mixed systems. This proposed methodology is used to find the optimal dimensional transistor parameters (length and width) in order to obtain operational amplifier performances for analog and mixed CMOS-(complementary metal oxide semiconductor-) based circuit applications. Six performances are considered in this study, direct current (DC) gain, unity-gain bandwidth (GBW), phase margin (PM), power consumption (P), area (A), and slew rate (SR). We used the Matlab optimization toolbox to implement the program. Also, by using variables obtained from genetic algorithms, the operational transconductance amplifier (OTA) is simulated by using Cadence Virtuoso Spectre circuit simulator in standard TSMC (Taiwan Semiconductor Manufacturing Company) RF 0.18 μm CMOS technology. A good agreement is observed between the program optimization and electric simulation.

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