ICCII-Based Voltage-Mode Filter with Single Input and Six Outputs Employing Grounded Capacitors

In this paper, a novel second-order voltage-mode filter with single input and six outputs employing inverting second-generation current conveyors (ICCIIs) is presented. This filter simultaneously realizes negative and positive gain lowpass, bandpass, and highpass filter responses, and does not require active and passive element matching. The new filter has low active and passive element sensitivities, and offers orthogonal control of the angular resonance frequency (ω_o) and quality factor (Q).     

ICCII-based universal current-mode analog filter employing only grounded passive components

In this paper, three versions of a novel second-order current-mode (CM) single-input three-output analog filter employing inverting second-generation current conveyors (ICCIIs) and only grounded passive components, are presented. This filter can simultaneously realize low-pass, band-pass and high-pass responses, and can also realize notch and all-pass filter responses with interconnection of the relevant output currents. The presented second-order filter requires no active and passive element matching conditions and/or cancellation constraints. The proposed filter offers orthogonal control of angular resonance frequency (ω_o) and quality factor (Q). The proposed filter can realize filter responses at high output impedances, and has low active and passive component sensitivities. Additionally, three versions of a high-order filter derived from the proposed filter are introduced. Simulation results using SPICE program are given to show the performance of the filter and verify the theory. Signal limitations and non-ideal current and voltage gain effects of the proposed second-order filter are also investigated.     

Generalized gyrator implementation techniques using unity-gain cells

All possible gyrator circuits using the minimum number of voltage and current unity-gain cells are extracted, as a result of generalizing the unity gains, such that a unity gain can be + 1 or ?1. Since second-generation current conveyors (CCIIs), possessing both voltage and current unity-gain cells, are very suitable for such gyrators, it is shown that inclusion of the recently proposed ‘inverting secondgeneration current conveyor’ (ICCII) in the design enables implementation of all types of extracted gyrators. The number of possible gyrator configurations is eight, one of them being the well-known Sedra–Smith gyrator and another its x -input counterpart; both utilize only CCIIs. The remaining possible six gyrators are new and utilize ICCIIs as well. Like the Sedra–Smith gyrator, all the circuits employ a minimum number of passive elements and similar types of active components, namely CCIIs and/or ICCIIs. The effects of current conveyor non-idealities and parasitics on important gyrator applications are also investigated. A highperformance dual-output CMOS ICCII is designed and used in SPICE simulations of two important gyrator applications in order to verify the theoretical results. Also, as a design example, an elliptic filter is realized and simulated.     

Tunable linear CMOS current mirror

Based on triode MOSFETs as tunable devices, a tunable linear current mirror is proposed, whose current gain is tunable over a wide range. Simulations show that, total harmonic distortion on the output current is within 2% for a tuning range of almost five octaves. Although the structure is in the form of an active-input current mirror, keeping the tuned MOSFETs in triode region significantly relaxes the stability problems of an active-input current mirror. This issue is revealed by theoretical analyses and further simulations are included for demonstration. An application example is also supplied.     

Electronically tunable multiphase sinusoidal oscillator using translinear current conveyors

A new electronically tunable current-mode multiphase sinusoidal oscillator based on translinear current conveyors is presented. The proposed oscillator circuit, which employs only one translinear current conveyor and one grounded capacitor for each phase, can generate arbitrary N output current equal-amplitude signals that are equally spaced in phase (N being even or odd), all at high output impedance terminals. The frequency of oscillation and the condition of oscillation can be controlled electronically and independently through the bias current of the translinear current conveyor. The proposed structure also has simple circuitry, low-component count, and is highly suitable for integrated circuit implementation. The theoretical results were verified by PSPICE simulation. In addition, the modification of the N sinusoidal oscillators to construct a programmable multiphase oscillator is also discussed.     

Current-conveyor-based single-element-controlled and current-controlled sinusoidal oscillators

A new single-element-controlled sinusoidal oscillator circuit that incorporates two second generation current conveyors (CCIIs), two grounded capacitors and two resistors is presented and analysed. The circuit is beneficial to monolithic integrated circuit implementation by the use of grounded capacitors. In addition, a new current-controlled sinusoidal oscillator using only two second generation current controlled conveyors (CCCIIs) and two grounded capacitors can be achieved by replacing CCIIs and resistors series at X terminals with CCCIIs. The oscillators provide extremely low passive ω₀-sensitivities and good frequency stability. Moreover, the oscillation frequencies of the CCII-based and the CCCII-based oscillators can be controlled, respectively, by a grounded resistor and by an external bias current. Experimental and SPICE simulation results that confirm the theoretical predictions are given.     

Generation of CCII and ICCII based Wien oscillators using nodal admittance matrix expansion

This paper introduces a new generation method of the grounded capacitor Wien oscillator circuits using current conveyors (CCII) or inverting current conveyors (ICCII) or combination of both of them. The nodal admittance matrix (NAM) of the single Op Amp Wien oscillator is taken as the starting point in the new approach of systematic synthesis of equivalent oscillators. The synthesis procedure is based on the generalized systematic synthesis framework using NAM expansion. The resulting derived 32 oscillators include many novel oscillators, using current conveyors or inverting current conveyors or both. Comparison between the generated oscillators based on the effect of parasitic elements on the oscillator performance is discussed.     

Current‐Mode Electronically Tunable Universal Filter Using Only Plus‐Type Current Controlled Conveyors and Grounded Capacitors

In this paper we present a new current‐mode electronically tunable universal filter using only plus‐type current controlled conveyors (CCCII+s) and grounded capacitors. The proposed circuit can simultaneously realize lowpass, bandpass, and highpass filter functions—all at high impedance outputs. The realization of a notch response does not require additional active elements. The circuit enjoys an independent current control of parameters ω₀ and ω₀ / Q. No element matching conditions are imposed. Both its active and passive sensitivities are low.     

DXCCII-based tunable gyrator

This letter presents a fully integrated active gyrator circuit based on the dual-X second-generation current conveyor (DXCCII), a recently introduced active element. The proposed circuit employs only two DXCCIIs and two triode MOSFETs for tuning the gyration conductances. Therefore, it is very suitable for integrated implementation of tunable active networks and especially simulation of tunable inductances.     

The dual-X current conveyor (DXCCII): a new active device for tunable continuous-time filters

In this work, a new active device, namely the dual-X current conveyor is proposed for linear tunable continuous-time filtering. The proposed device avails tunability with the aid of triode MOSFETs, while keeping large-signal linearity high. Besides linearity enhancement, the dual-X structure of the active device brings interesting features, which help reduce the required number of active devices and MOSFET resistors in a MOSFET-C continuous-time filter. Also, unlike most MOSFET-C filter structures, there does not exist a matching requirement for the utilized MOSFETs. A CMOS implementation and two application examples (a current mode Tow-Thomas biquad and a current-mode sinusoidal oscillator) are supplied and simulated to reveal the important advantages.     

Novel current-mode biquadratic circuit using only plus type DO-DVCCs and grounded passive components

This paper introduces a novel current-mode biquadratic circuit using plus type differential voltage current conveyors (DVCCs) and grounded passive components. The circuit is constructed with two plus type dual current output DVCCs (DO-DVCCs), two grounded capacitors and two resistors. The circuit can realize multiple circuit transfer functions by choosing the appropriate input and output terminals. Additionally, the circuit parameters Q and ω ₀ can be set orthogonally by adjusting the passive components. The biquadratic circuit enjoys very low sensitivities to the circuit components. An example is given together with simulated results by PSPICE.     

Current-tunable current-mode multifunction filter based on dual-output current-controlled conveyors

In this paper, a current-tunable current-mode multifunction filter with two inputs and two outputs employing only four dual-output current-controlled conveyors (DO-CCCIIs) and two grounded capacitors is proposed. By appropriately connecting the input and output terminals, the proposed circuit can provide lowpass, bandpass, highpass, bandstop and allpass current responses. The filter also offers an independent electronic control of the natural frequency (ω_o) and the quality factor (Q) through adjusting the bias currents of the DO-CCCIIs. No critical matching conditions are imposed for realizing all the filter responses, and all the incremental parameter sensitivities are low. The characteristics of the proposed circuit are simulated using PSPICE to confirm the theory.     

Versatile current-mode biquadratic circuit using only plus type CCCIIs and grounded capacitors

This paper introduces a versatile current-mode biquadratic circuit using second generation current-controlled current conveyors (CCCIIs). The circuit is constructed with two plus type multiple current output CCCIIs (MO-CCCIIs) and two grounded capacitors. The circuit can realize low-pass, band-pass, high-pass, band-stop and all-pass transfer functions by choosing appropriate input and output terminals without any component matching conditions. Additionally, the circuit parameters Q and ω₀ can be set orthogonally by adjusting the bias currents of the MO-CCCIIs and grounded capacitors. The biquadratic circuit enjoys very low sensitivities to the circuit components.

Some examples are given together with simulated results by PSPICE.     

Analog and radio-frequency performance analysis of silicon-nanotube MOSFETs

This work presents a comparative study of the influence of various parameters on the analog and RF properties of silicon-nanotube MOSFETs and nanowire-based gate-all-around (GAA) MOSFETs. The important analog and RF performance parameters of SiNT FETs and GAA MOSFETs, namely drain current (I_d), transconductance to drain current ratio (g_m/I_d), I_on/I_off, the cut-off frequency (f_T) and the maximum frequency of oscillation (f_MAX) are evaluated with the help of Y- and H-parameters which are obtained from a 3-D device simulator, ATLAS^TM. It is found that the silicon-nanotube MOSFETs have far more superior analog and RF characteristics (g_m/I_d, f_T and f_MAX) compared to the nanowire-based gate-all-around GAA MOSFETs. The silicon-nanotube MOSFET shows an improvement of~2.5 and 3 times in the case of f_T and f_MAX values respectively compared with the nanowire-based gate-all-around (GAA) MOSFET.     

Tunable Ladder-Type Realization of Current-Mode Elliptic Filters

It is shown that a new series FDNR-R equivalent circuit using current controlled current conveyors (CCCIIs) allows effective realization of jω-axis zeros which are known to complicate the active implementation of ladder-type elliptic filters. The resulting ladder-type elliptic filter employs all grounded capacitors while keeping the number of active elements small. Also, the filter parameters are electronically tunable, which is important from integration point of view.     

A new analytical subthreshold model of SRG MOSFET with analogue performance investigation

For the first time, a pseudo-two-dimensional (2D) approach is extended from a rectangular device structure to a cylindrical one. A pseudo-2D model applying Gauss's law in the cylindrical channel depletion region for undoped or lightly doped surrounding gate (SRG) silicon metal oxide semiconductor field effect transistor (MOSFETs) working in subthreshold regime is presented. From this pseudo-2D analysis, electrostatic potentials, current characteristics, the threshold voltage roll-off, the drain-induced barrier lowering and the subthreshold swing are explicitly modelled. The obtained analytical model has been extended to develop a model for transconductance-to-drain current ratio (g _m/I _d) in weak inversion regime. Analogue figures of merit of SRG MOSFETs are studied, including transconductance efficiency g _m/I _d, intrinsic gain and output resistance. The trends related to their variations along the downscaling of dimension are provided. In order to validate our model, the modelled expressions are compared with the simulated characteristics obtained from ATLAS device simulator.     

Characteristics of bifacial solar cells under bifacial illumination with various intensity levels

The characteristics of bifacial solar cells with different rear structures were investigated under front, rear and bifacial illumination with an intensity of 0.4–4.2 suns. Five kinds of solar cells, rear flat local‐BSF cells, rear textured local‐BSF cells (textured RLB cells), rear total‐BSF cells, rear floating‐emitter cells, and triode cells with double‐sided junctions, were tested. The I–V characteristics of the cells under bifacial illumination were measured with a newly designed measurement system that simultaneously illuminated both surfaces of the cells. In the short‐circuit current (J_SC) and the saturation current evaluations, the bifacial illumination effect, which means that the power output of the cell is intrinsically improved by adding rear illumination, was not observed. Although the RLB cells showed a nonlinear increase in J_SC and enhanced V_OC, these increases did not make a practical contribution to extra output because of the low levels of these characteristics. When we evaluated the maximum output power, the bifacial illumination effect was only observed in the triode cell. A triode cell can decrease resistive loss by introducing light from both surfaces, compared with a conventional cell with one junction. Copyright © 2001 John Wiley & Sons, Ltd.     

A New Current-Mode Current-Controlled Universal Filter Based on CCCII(±)

This paper proposes a new current-mode current-controlled single-input multiple-output type universal filter using non-inverting and inverting second generation current-controlled conveyors (CCCII(±)s). The proposed circuit employs four CCCII(±)s and two grounded capacitors, and it can simultaneously realize lowpass, bandpass, highpass, bandstop and allpass filter outputs. The circuit offers an independent electronic control of the natural angular frequency (ω ₀) and quality factor (Q) by means of adjusting the bias current of the CCCII(±)s. The parameter sensitivities are all very low. Moreover, a high Q-value filter can be easily obtained by adjusting the ratio of two bias currents. PSPICE simulation results at the natural frequency of 1.27 MHz are given to demonstrate the advantages of the proposed circuit. This work was supported by National Natural Science Foundation of China under No.60676021.     

Organic inverter: Theoretical analysis using load matching technique

This paper reports the analysis of key parameters affecting voltage transfer characteristics of pseudo PMOS organic inverters. Pentacene has been used as active material for PMOS Organic Thin Film transistor (OTFT). We have used two different inverter configurations for thorough analysis. Each configuration comprises of an enhancement mode driver (V_Threshold = −9.7 V) and a depletion mode load (V_Threshold = 11.7 V). First configuration has its source and gate terminals shorted. While, second configuration differs with its drain and gate terminals shorted. In order to surmise the theoretical performance of the inverters, we have used load matching technique. After investigating various parameters such as inverting gain, noise margin values (immunity to noise error signals) and threshold voltage value, influencing the voltage inverting efficiency of the two configurations mentioned above, it was found that an inverter with shorted source-gate load configuration is better of the two due to privileges such as saturation mode operation of load, low driver current with early saturation of enhancement mode driver, which facilitates full swing output voltage operation. Second configuration with shorted drain-gate load, lacks saturation mode operation of load and fails to deliver high voltage swing along with acceptable noise margin values and inverting gain.     

Floating inductance,FDNR and capacitance simulation circuit employing only grounded passive elements

A circuit for realizing floating inductance, grounded to a floating admittance converter, floating frequency dependent negative resistance (FDNR) and floating capacitance simulators depending on the passive element selection is presented. The proposed circuit employs only grounded passive elements and second-generation current conveyors (CCIIs) but it requires single passive component matching. Replacing second-generation current controlled conveyors (CCCIIs) instead of the CCIIs in the developed circuit, an electronically tunable floating inductor with bias currents can be obtained. Also, replacing dual X second-generation current conveyors (DXCCIIs) instead of the CCIIs in the introduced circuit, an electronically tunable floating inductor with bias voltages can be obtained. Under non-ideality conditions, the proposed circuit can realize a lossless floating inductor and a capacitor depending on the passive element choice. Simulation results using SPICE program are given to verify the theory.