Second-generation Current-controlled Conveyors Research Articles

MO-CCCII-Based Single-Input Multi-Output (SIMO) Current-Mode Fractional-Order Universal and Shelving Filter

This study introduces an innovative filter topology capable of providing simultaneous positive and negative gain outputs for one-fractional order LP, with high-pass, all-pass, and fractional-order shelving filter responses. The circuit, utilizing multi-output second-generation current-controlled conveyors, stands out as the first to deliver ten outputs, incorporating both integer and fractional-order filter responses, without requiring additional components. Its current-mode design simplifies the process, employing minimal active and grounded passive elements, making it appropriate for low-voltage/low-power applications. The filter utilizes fifth-order Oustaloup approximation and Foster type-I RC networks for fractional-order capacitors, providing enhanced control over the transition slope. PSpice simulations confirmed a 1 kHz cut-off, showcasing low power consumption, minimal noise, and a wide dynamic range, positioning the filter as suitable for sensors, control, and acoustic applications.

Systematic Synthesis for Electronic-Control Colpitts Oscillator Using CCCIIs

By the aid of nullor-mirror models of the second-generation current-controlled conveyor (CCCII) and applying the nodal admittance matrix (NAM) expansion method, the family of current-mode Colpitts oscillators employing four CCCIIs and three grounded capacitors is synthesized. Thirty-two Colpitts oscillators using CCCIIs are obtained in all. By using canonical number of components, the circuits can be easily integrated and the oscillation criterion and the oscillation frequency can be independently and electronically tuned by tuning bias currents of the CCCIIs. The paper-and-pencil analysis and Pspice simulation results have been included to support the synthesis method.

A First-Order Fully Cascadable Current-Mode Universal Filter Composed of Dual Output CCIIs and a Grounded Capacitor

In this paper, a new first-order current-mode (CM) universal filter employing two dual output second-generation current conveyors (DO-CCIIs), one resistor and a grounded capacitor is proposed. The proposed filter has low input and high output impedances; thus, it can be easily connected with other CM circuits. It can simultaneously realize first-order low-pass (LP) and all-pass (AP) responses and can provide high-pass (HP) response with interconnection of LP and AP responses. It can be tuned electronically by replacing with dual output second-generation current controlled conveyors (DO-CCCIIs) instead of DO-CCIIs and removing the resistor. It has only a resistor but no capacitor connected in series to X terminal of DO-CCII; accordingly, it can be operated at high frequencies. Also, it does not need any critical passive component matching conditions and cancellation constraints. A number of simulation results based on SPICE program are included to exhibit performance, workability and effectiveness of the proposed filter configuration.

Systematic synthesis of CCCCTA-based T-T filters using NAM expansion method

ABSTRACTIn the light of nullor-mirror models for current-controlled current conveyor trans-conductance amplifier (CCCCTA), initiating the admittance matrices of the Tow-Thomas (T-T) filter, three different types of the T-T filter are synthesised by means of the nodal admittance matrix (NAM) expansion method. The type A filter, which employ one CCCCTA, one grounded resistor and two grounded capacitors, has eight different forms, the type B filter, which employ one CCCCTA, two grounded capacitors and a second-generation current-controlled conveyor (CCCII) or an second-generation inverting current-controlled conveyor (ICCCII) or an operational trans-conductance amplifier (OTA), has 64 different forms and the type C filter employing one CCCCTA and two grounded capacitors has eight different forms. In all, 80 voltage-mode/current-mode T-T filter circuits are obtained. Because of using canonic number components, the circuits are highly desirable from the viewpoint of IC fabrication and their parameters can be electronically tuned through tuning bias currents of CCCCTAs. The hand analysis and computer simulation results have been provided to support the synthesis method.

A New Current-Mode Universal Filter with Single-Input Five-Output Using Trans-Linear Current Conveyors

This paper presents a new current-mode current-controlled one-input five-output universal filter, employing only three trans-linear current conveyors and two grounded capacitors. The proposed configuration provides low-pass, band-pass, high-pass, band-stop and all-pass current responses. It exhibits low-input and high-output impedances, which is highly desirable for cascading in current-mode. Also, it offers the advantage feature of an independent electronic control of the natural frequency (ω J and the quality factor (Q) through tuning the external bias currents. Moreover, a high Q-value filter can be obtained by separately adjusting the appropriate current gain of CCCII (second-generation current controlled conveyor). The active and passive sensitivities of the filter are low. The characteristics of the proposed circuit are simulated using PSPICE to confirm the theoretical analysis.

Cognitive and encrypted communications: state of the art and a new approach for frequency-agile filters

Several communication techniques are investigated in the first part of this paper: software radio, cognitive radio and encrypted communications. State of the art of research on agile and reconfigurable filters, passive as well as active, necessary for transceivers is then made and various tables for comparison are given. In the third part, a new theory for a 2^{nd}-order frequency-agile filter is introduced. The center frequency of the filter is proportional to the gain of a feedback amplifier and thus can be tuned over a wide frequency range. This new theory is thereafter generalized to the n^{th}-class leading to a center frequency proportional to (A)^{n/2}. Simulation results of band pass agile filters in current mode and made from second-generation current controlled conveyors (CCCII+) in 0.25 \mu m SiGe BiCMOS technology are given for n = 1 and n = 2. These simulation results along with results of measurements carried out on the fabricated filters entirely confirm the new approach. They also highlight the improvements to be expected for cognitive and encrypted communications.

Design of tunable biquadratic filters employing CCCIIs: state variable block diagram approach

A state variable block diagram method is given for the realization of universal biquadratic transfer functions employing second-generation current-controlled conveyors (CCCIIs). Using minimum number of passive components and properly adjusting the bias currents of CCCIIs, the proposed circuits can realize all the tunable frequency standard filter functions: high-pass, band-pass, low-pass, notch-pass, and all-pass by choosing appropriate input branches without changing the passive elements. These presented circuits are in current-mode and voltage-mode separately. The non-ideality analyses of these configurations are given. Additionally, a high-order low-pass filter derived from the proposed voltage-mode biquadratic filter is introduced. PSPICE simulation results are included to verify the theory.

Design of a Simple Current-Mode Multiplier Topology Using a Single CCCII+

In this paper, an analog current-mode (CM) multiplier circuit employing a single plus-type second-generation current-controlled conveyor (CCCII+) and a grounded resistor is proposed. The developed circuit can provide two-quadrant multiplication, four-quadrant multiplication, and frequency doubling all from the same topology with the selection of the applied input currents. In addition to the signal limitations of the multiplier configuration, the nonideality effects of the CCCII+ and the nonideal gain and parasitic impedance effects on the proposed circuit are investigated. The realized circuit is simulated with SPICE to exhibit its performance. In addition, a CM multiplier derived from the proposed multiplier is set up with commercially available active components to easily perform its experimental test.

CURRENT-MODE ACTIVE-C FILTER EMPLOYING REDUCED NUMBER OF CCCII+s

In this paper, a universal current-mode second-order active-C filter for simultaneously realizing low-pass, band-pass and high-pass responses is proposed. The presented filter employs only three plus-type second-generation current-controlled conveyors (CCCII+s). This filter needs no critical active and passive component matching conditions and no additional active and passive elements for realizing high output impedance low-pass, band-pass and high-pass characteristics. The angular resonance frequency (ω0) and quality factor (Q) of the proposed resistorless filter can be tuned electronically. To verify the theoretical analysis and to exhibit the performance of the proposed filter, it is simulated with SPICE program.

New simple square-rooting circuits based on translinear current conveyors

Two new square-rooting circuits, based on second-generation current-controlled current conveyors (CCCIIs), are presented. The first square-rooting circuit consists of two CCCIIs, one current-controlled resistor and two grounded resistors. The input signal of the first circuit is a voltage, and output is the voltage proportional to the square root of input voltage. The second one consists of two CCCIIs and a current-controlled resistor. In the second circuit, the input signal is a current, and output is the current proportional to the square root of input current. Each circuit realizes by using a current-mode technique; hence the proposed square-rooting circuits are simple circuitry, wide dynamic range and wide bandwidth. The proposed square-rooting circuits were confirmed by using PSPICE simulation.

New High-Value Floating Controlled Resistor in CMOS Technology

A new implementation of a floating controlled resistor in CMOS technology is introduced. The proposed circuit uses two second-generation current-controlled conveyors. With a supply voltage of plusmn3.3 V and a null load resistor, the simulated results show that the equivalent resistance decreases from 24.2 to 7.8 kOmega when the bias current is varied from 20 to 200 muA. Implemented in an industrial 0.8-mum CMOS process, its frequency response is up to 115 MHz for a bias current of 100 muA. For a load resistor of 10 kOmega and with the same conditions, the equivalent resistance varies from 93.3 to 60.2 kOmega

All-pass filters based on CCII− and CCCII−

This paper proposes a first-order all-pass filter using one negative type second-generation current conveyor (CCII−), two resistors and a capacitor. From the proposed CCII− based filter, by replacing the CCII− and a resistor by a negative second-generation current-controlled conveyor (CCCII−) a new filter is developed which requires only one each of CCCII−, capacitor and resistor. The experimental and simulated results are found in good agreement with theoretical analysis. The circuits are also analyzed for non-ideal current conveyors to show that they still function as all-pass filters but with slight altered values of gain and phase.

A novel single-input multiple-output current-mode current-controlled universal filter

A novel current-controlled current-mode universal filter is presented. The circuit uses six second-generation current-controlled conveyors and two grounded capacitors. The circuit enjoys independent control of the parameters ω 0 and ω 0/ Q 0, low active and passive sensitivities and can simultaneously realize all the five basic filter transfer functions. SPICE simulation results are included.

A new current-controlled multiphase sinusoidal oscillator using translinear current conveyors

A multiphase sinusoidal oscillator circuit is presented. The oscillator can produce N output-currents (N being even or odd) equally spaced in phase. The circuit uses translinear bipolar second-generation current-controlled conveyors, grounded capacitors and enjoys low active and passive sensitivities and independent current-control of the frequency of oscillation.

A Novel Current-Controlled Oscillator Using Translinear Current Conveyors

A novel oscillator circuit using the translinear current conveyor is presented. The circuit uses three second-generation current-controlled conveyors and two grounded capacitors. The circuit enjoys independent control of the frequency and the condition of oscillation using bias currents. SPICE simulation results are included.