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This work describes voltage-mode (VM), current-mode (CM) PID controllers and an electrically controllable floating inductance (FI) simulator circuit. Only a single current-controlled current backward transconductance amplifier (CC-CBTA) and a grounded capacitor are used in the proposed FI simulator circuit. One CBTA, one CC-CBTA, two capacitors and one resistor are used in the proposed PID controllers. All of the proposed circuits have appropriate input and output impedance values, allowing them to be utilized in cascade connections without requiring a buffer circuit. There is also no matching constraint between the active and passive values of the proposed circuit. The SPICE software environment and experimental results were used to validate theoretical derivations and associated outcomes. The layout of the CC-CBTA has been built, and the post-layout simulations are carried out using the netlist extracted from the layout. Comparisons were made with similar circuits found in the professional literature. [ABSTRACT FROM AUTHOR]

In this paper, a new realization of a current-mode first-order all-pass filter (APF) using a single active building block (ABB) and one grounded capacitor is presented. As the ABB, the current backward transconductance amplifier (CBTA) is used, which is one of the most recently reported active elements in the literature. The theoretical results are in detail verified by numerous SPICE simulations using a new low-voltage implementation of CBTA. In the design, the PTM 90nm level-7 CMOS process BSIM3v3 parameters with 0.45V supply voltages were used. The proposed resistorless CBTA-C APF provides easy electronic tuning of the pole frequency in the frequency range from 763kHz to 17.6MHz, which is more than one decade. Maximum power dissipation of the circuit is 828W at bias current 233A. Nonideal, parasitic effects, sensitivity analyses, temperature and noise variation, current swing capability, and Monte Carlo analysis results are also provided. Compared to prior state-of-the-art works, the proposed CBTA-C APF has achieved the highest figure of Merit value, which proves its superior performance. [ABSTRACT FROM AUTHOR]

The aim of this paper is proposing an alternative method to Gorski-Popiel Technique in realization of synthetic transformers. A new synthetic floating transformer (FT) circuit is also given. The proposed synthetic transformer circuit uses two current backward transconductance amplifiers (CBTAs), three resistors, and two grounded capacitors. The primary self-inductance, the secondary self-inductance, and the mutual inductance can be independently controlled and can be tuned electronically by changing the biasing current of the employed CBTAs. It has a good sensitivity performance with respect to tracking errors. A band-pass filter is also realized to test the performance of the proposed synthetic transformer circuit. The validity of the proposed synthetic transformer circuit is demonstrated by PSPICE simulations and experimental results. [ABSTRACT FROM AUTHOR]

ABSTRACT In this article, a general all-pole current transfer function synthesis procedure using current backward transconductance amplifiers (CBTAs) is proposed. The proposed configuration uses n current backward transconductance amplifiers and n grounded capacitors as the only type of passive elements. The circuit is eligible to realize any all-pole transfer characteristics with a given strictly Hurwitz (stable) denominator polynomial. Further, it is straightforward to find the values of the passive elements from the coefficients of this polynomial by using the Routh-Hurwitz algorithm as in the realization of a two-element kind passive network synthesis. In this sense and as far as the author's knowledge, it is the only active structure that can be synthesized like a passive two-element kind Cauer circuit. The simulations that are performed using PSPICE exhibit satisfactory results coherent with the theory. Copyright © 2011 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

A new circuit configuration for the realisation of an electronically tunable sinusoidal oscillator is presented. The proposed circuit uses only one current backward transconductance amplifier (CBTA), two grounded capacitors and one resistor. Using current controlled CBTA (CC-CBTA) instead of the CBTA, the resistor can be completely removed. It has also current-mode (CM) and voltage-mode (VM) outputs, simultaneously. The workability of the proposed structure has been demonstrated by both simulation and experimental results. [ABSTRACT FROM PUBLISHER]

A novel circuit for the realization of the mutually coupled circuit using three current-controlled current backward transconductance amplifiers (CC-CBTAs) as active components is proposed. The active mutually coupled circuit structures are also called the synthetic transformers. The circuit is derived by using three floating simulated inductors that are connected as the T-type transformer model. The circuit has the following attractive advantages: (i) The values of a primary self-inductance, a secondary self-inductance and a mutual inductance can be independently tuned by the transconductance gain of the CC-CBTAs; (ii) The circuit uses three grounded capacitors that are suitable from the point of integrated circuit implementation; (iii) It uses only three active components; (iv) It has a good sensitivity performance with respect to the tracking errors; (v) Both positive and negative couplings are achieved and the coupling coefficient is not limited by 1 in magnitude; (vi) Symmetrical coupling is achieved without necessitating any matching condition; (vii) The proposed circuit has a floating structure. [ABSTRACT FROM AUTHOR]

In this paper, a general electronically tunable resistorless biquad, which realizes current ratio transfer function using current backward transconductance amplifiers is proposed. The biquad contains only two active components and two grounded capacitors, which make it convenient for production by the integrated circuit technology. The proposed biquad realizes all of the basic second order filter characteristics: low pass, high pass, band pass, band reject, and finally all pass. It is convenient for cascading with other similar biquads as well as with any two-port circuit with low impedance input to achieve higher order filter characteristics. The simulations that are performed using PSPICE simulator exhibit satisfactory results coherent with the theory. [ABSTRACT FROM AUTHOR]

Abstract: In this study, a novel immittance simulator circuit is proposed. The proposed circuit can simulate any one of the floating positive or negative inductor simulator (±L), positive or negative capacitor simulator (±C) and positive or negative resistor simulator (±R). It uses only one current backward transconductance amplifier (CBTA) and two grounded passive components. The proposed simulator can be tuned electronically by changing the transconductance value of the CBTA. Moreover, the circuit does not require any conditions of component matching. It has a good sensitivity performance with respect to the tracking errors and the passive components. The performance of the proposed immittance simulator is demonstrated on the fourth-order voltage- and current-mode band-pass filters by using Pspice simulations based on the 0.25μm TSMC level-7 CMOS technology parameters. [Copyright &y& Elsevier]

Abstract: In this paper, a new multi-terminal active component, namely current backward transconductance amplifier (CBTA) is proposed. The design procedure for the systematic realization of current-mode ladder filters using proposed active component is also presented. In order to demonstrate that the CBTA considerably simplifies the leapfrog structure of the current-mode ladder filters, a fifth-order Butterworth low-pass filter that requires a minimum of active components is presented. The theoretical results are demonstrated by using PSPICE simulation. [Copyright &y& Elsevier]

A SPICE-compatible macromodel for emulating the nonlinear behavior of the current backward transconductance amplifier (CBTA) at low-frequency is developed. The novelty of the proposed macromodel is that real physical active device performance parameters together with parasitic elements of the input–output terminals of the CBTA are taken into account. In a first step, the CBTA is designed with ± 2.5 V by using standard CMOS technology of 0.35 μ m AMS and the main performance parameters, such as: DC gain, bandwidth, slew-rate, dynamic range, along with parasitic elements are obtained. In a second step, the behavioral model of the CBTA is deduced and the SPICE-compatible macromodel is built. In a third step and to validate the deduced behavioral model, two topologies of saturated nonlinear function series (SNFS) based on CBTA are designed. At this point, a generated experimentally chaotic signal was applied as excitation signal to each SNFS built with the CBTA at the transistor level and to the proposed SPICE-compatible macromodel. As a consequence, the derived macromodel can effectively be used for forecasting the behavior of nonlinear circuits in the time-domain with good accuracy, decreasing the CPU-time compared with the model at the transistor level of abstraction. [ABSTRACT FROM AUTHOR]