New VDCC based electronically tunable grounded frequency dependent negative resistance simulator employing grounded passive elements

The purpose of this paper is to present ground frequency dependent negative resistance (FDNR) using voltage differencing differential input buffered amplifier (VDDIBA) active element. The presented FDNR circuit is developed using two VDDIBAs, two capacitors and a single resistor, the use of VDDIBA in FDNR implementation has not been reported in open literature so far. Therefore, this work can be considered as a base for future research in this area. The presented realization offers electronic control of simulated negative resistance value through the biasing current of used VDDIBAs. There is no requirement for matched active/passive component in this design with low sensitivity indexes. In order to verify the behaviour of the presented configuration, the band reject and bandpass filter design examples have been developed. All the presented circuits have been tested by PSPICE simulation tool. For simulation purposes, the VDDIBA has been implemented by CMOS OTA and AD844 CFOA.

This paper presents a comparison and performance analysis of CMOS-based VDCC (Voltage Differencing Current Conveyor) circuits and differential amplifier FGMOS-based circuits. Differential amplifiers at the input stage of the VDCC circuit are designed using FGMOS instead of CMOS. Designing the differential amplifiers in the input stages of the VDCC circuit using FGMOS instead of CMOS amplifies the input signal of the circuit, providing a significant increase in linearity and voltage following properties. At the same time by using FGMOS transistors, the input stage of the circuit, which provides arithmetic calculations, is simplified. A three-input single output (TISO) type band-pass filter application is given to show the versatility of the VDCC circuit topology. The THD value of the CMOS-based VDCC filter circuit is found to be 15.99%. The THD value of the proposed differential amplifiers FGMOS-based VDCC filter circuit is found to be 1.03%. Theoretical analysis results confirm the simulation results. The presented CMOS and FGMOS-based band-pass filters are simulated using TSMC CMOS 0.18 μm technology with VDD, a power supply voltage equal to 0.9 V. The proposed circuit topology will be an essential reference in the literature for researchers to design new linearly tunable filters.

This paper describes switched-capacitor (SC) inductor and Frequency Dependent Negative Resistor (FDNR) which use second generation current conveyor (CC II). In general CC II's used in SC circuits are not always used as CC II and there are phase periods in which CC II behaves as much simpler active device like unity gain buffer (UGB). In this paper, CC II's in SC circuits always behave as CC II to make full use of CC II. Then an SC inductor in which effects of parasitic capacitors can be reduced is proposed. And SC FDNR which uses CC II to get a simple circuit structure is also proposed. Both circuits are controlled by simple two-phase control clock. The spreads of capacitor values are 1. The sum of capacitor values of SC FDNR is 4. This value is the smallest reported value in SC FDNR circuits. Simulation results by SWITCAP and experimental results by discrete components are shown.

The design of transconductance-mode multifunction biquad filter containing three input voltage nodes and single-output current node is proposed. Its circuit principle is emphasized on employing Voltage Differencing Current Conveyor (VDCC) to be an active building block. The proposed filter description uses three VDCCs co-working with two grounded capacitors and three grounded resistors. The synthesis of the proposed multifunction filter is based on avoidance of using multiple-output active elements to achieve commercially available integrated circuits for practical implementation. Additionally, without multiple-output active element, it can alleviate current tracking error from the current mirrors used in output ports. It also decreases the amounts of the transistors inside the active elements. The proposed multifunction filter offers all 5 filter functions, which are non-inverting Low-Pass (LP), non-inverting High-Pass (HP), non-inverting Band-Pass (BP), non-inverting Band-Reject (BR) and also non-inverting All-Pass (AP) functions from same circuit topology under different circuit condition for input signals. Furthermore, the natural frequency for all filtering responses is independently achieved from the bandwidth or the quality factor of the proposed filter. For cascade-able connectivity, the output current port indeed provides a high impedance. In addition, the magnitude of the output current for all filtering functions can be resistively adjusted. The consideration for non-ideal case of the presented multifunction filter is also analyzed. The simulation and experimental results of the presented transconductance multifunction biquad filter based on VDCC practically implemented by the commercially available ICs, LM13700 and AD844 can validate the theoretical anticipation.

This paper presents a novel One-shot pulse Generator Circuit, which is composed of only one differential voltage current conveyor (DVCC) as the active element. The application circuits utilizing the DVCC are introduced and implemented. Only one DVCC and two resistors and one capacitor are required to construct every circuit. Each circuit is able to provide a pulse-shaped response having changeable width via a positive-edge triggered signal. The first one is a general one-shot pulse generating circuit. The second design can reduce the recovery time after applying triggered signals. Is-Spice is the simulation software to simulate every model. To fabricate the models commercially available ICs (AD844AN) and passive elements are required. Program and experimental outputs satisfy theoretical results.

Floating general immittance function simulator

A new CMOS dual-X second generation current conveyor (DXCCII) with an FDNR circuit application

Design and implementation of monostable multivibrators employing differential voltage current conveyors

A switched-capacitor filter using a frequency-dependent negative resistance (FDNR) is described. FDNR filters closely simulate passive LC filters, thereby retaining passband stability and design simplicity. The filter has been implemented in LSI and designed to perform the transmit/receive filtering for PCM codecs. Circuits are described that overcome the floating node and floating amplifier problems previously associated with FDNRs.

Article On the Realization of Second Order Current Mode Active Filters Using Single Differential Voltage Current Conveyor (DVCC) was published on May 1, 2003 in the journal Frequenz (volume 57, issue 5-6).

This chapter discusses prominent contributions made over the last five decades on the evolution of gyrators, synthetic inductances and other related immittances using current conveyors (CCs) and their numerous variants developed over the years. The various circuits using the most basic forms of CCs, namely the first-generation CCs (CCI) and the second-generation CCs (CCII) have been elaborated first. This is then followed by the circuits employing an electronically controllable version of CCII called controlled second-generation current conveyor. Finally, numerous recent circuits based on different variants of CCs such as dual-output CCIIs, differential voltage CCs, third-generation CCs, differential difference CCs, inverting CCII, dual-X CCII and fully differential CCII and numerous combinations thereof have been dealt with. A number of applications of the various synthetic impedances have been elaborated.

Three port gyrator circuits using transconductance amplifiers or generalized conveyors

This paper presents a theory for single-stage circulator-coupled negative resistance reflection amplifiers based on proposed realistic circuit models for frequency-dependent band-limited circulators and broadband negative resistance devices such as the tunnel diode. In particular, gain bandwidth limitations are derived which are imposed by both the inherent resonance associated with the nonreciprocal circulator junction and the reactive parasitic associated with the active device. These limitations are generally more restrictive than past results which assumed a "perfect" frequency-independent circulator and took into account only the device parasitic. In addition, a synthesis procedure is presented for realization of an absolutely stable amplifier with a prescribed nth-order Butterworth or Chebyscheff approximation to an ideally flat band-pass power gain characteristic. The approach employed is based upon the theory of reflection coefficient equalization between two reactively constrained resistances representing the pass band circulator and device immittance models. In addition, a band rejection out-of-band stabilizing network is absorbed in the pass band equalizer in accordance with an over-all synthesis procedure. Finally, the theory is verified by the construction and testing of an L-band tunnel diode amplifier having third-order maximally flat power gain centered at 1.46 Gc/s and with half-power bandwidths (430 Mcls and 355 Mc/s at 10 dB and 16dB midband gain) within six percent of those predicted by theory.

MOS-C realizations of the Kerwin–Huelsman–Newcomb (KHN) circuit using the commercially available Voltage Operational Amplifier (VOA) and the Current Feedback Operational Amplifier (CFOA) are reviewed in this paper. Additional MOS-C KHN realizations using the Operational Transresistance Amplifier (OTRA) and the Differential Current Voltage Conveyor (DCVC) are also included. MOS-C realizations of the KHN circuit using CMOS operational amplifier, CMOS current feedback operational amplifier and CMOS operational transresistance amplifier are also given.Spice simulation results using 0.18 CMOS technology model from MOSIS are included together with detailed comparison tables to demonstrate the differences between MOS-C KHN circuits using both of the commercially available active building blocks and CMOS integrated building blocks. A comparison with the Gm-C KHN circuit is also included.

In this paper, the effect of non-idealities of CFOA and G <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">m</inf> -block used in a recently proposed impedance multiplier is studied. Since the CFOA is used in open-loop mode, the effect of series resistance of the CCII at x terminal, input impedance of the CCII at y terminal, the output impedance of the CCII at z terminal and the output impedance of the G <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">m</inf> -block are analyzed. The effect of these non-idealities on applications of the capacitance multiplier to realize second-order low-pass, band-pass and notch filters using external resistance and inductance is studied in detail, SPICE simulation results are also provided. The proposed impedance multiplier is explored to realize a generalized immittance converter (GIC) using current conveyor, G <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">m</inf> -block and two impedance elements. The immittance converter circuit is shown to realize various simulated grounded elements like positive/ negative inductor, resistance/ capacitance multiplier, frequency dependent negative resistor (FDNR) and super inductor etc.