Single-resistance-controlled Oscillator Research Articles

New explicit-current-output SRCO using a single CFOA and all grounded capacitors

A new explicit-current-output (ECO) single-resistance-controlled-oscillator (SRCO) using a single CFOA has been presented which (i) provides independent control of the condition of oscillation and the frequency of oscillation (both through two separate resistors) (ii) employs all grounded capacitors (as preferred for IC implementation) (iii) is suitable for generating very-low-frequency oscillations and (iv) enjoys control of oscillation frequency through a ground resistor (thereby offering suitability for VCO realisation by replacing the resistor by JFET/MOSFET-based voltage-controlled-resistance). The proposed circuit represents a significant development due to the reason that although ECO SRCOs have been reported earlier using two or more CFOAs, to the best of the authors’ knowledge, any circuit using only a single CFOA along with the simultaneous attainment of the above mentioned properties, has not been reported in the literature earlier till date. The workability of the proposed circuit has been verified by experimental results using AD844-type CFOA and some sample results have been included.

Novel current feedback operational amplifier‐based configuration that realizes a single‐input multiple‐output‐type universal active filter and a single‐resistance‐controlled oscillator

AbstractA new configuration employing five current feedback operational amplifiers (CFOAs), six resistors, and two grounded capacitors is proposed, which realizes a single‐input‐multiple‐output (SIMO)‐type voltage‐mode (VM) universal active filter and a single‐resistance‐controlled oscillator (SRCO) and simultaneously provides the following novel features: (i) realizability of all the five generic filter functions namely, low pass filter (LPF), high pass filter (HPF), band pass filter (BPF), band reject filter (BRF), and all pass filter (APF) at the five output terminals of the five CFOAs; (ii) infinite input impedance and zero output impedance in all the realizations; (iii) availability of orthogonal tunability of the filter parameters (pole frequency, quality factor/BW, and gain); (iv) realizability of an SRCO exhibiting independent control of the condition of oscillation (CO) and frequency of oscillation (FO) by the simple artifice of changing one circuit connection; and (v) use of both grounded capacitors, as preferred for IC implementation. To demonstrate the workability of the proposed configuration, SPICE simulation results and experimental results have been included.

Single-CFOA-Single-External-Capacitor-Based Partially-Active-R SRCOs: The Fourth Missing Circuit

A new single-resistance-controlled-oscillator (SRCO) is presented which employs a single current feedback-operational amplifier (CFOA) along with four resistors but needs only a single external capacitor due to the incorporation of the CFOA-pole in the design. It provides independent control of the condition of oscillation and the frequency of oscillation through two separate resistors. To the best knowledge of the authors, this single-CFOA-based partially active-[Formula: see text] SRCO has not been reported explicitly in the technical literature earlier and hence is the fourth missing circuit of this class of SRCOs. Experimental results confirming the validity of the new proposition have been included and the comparative features of all the four circuits have been highlighted.

Lossless grounded FDNR simulator and its applications using OTRA

In this paper, a new grounded positive lossless frequency dependent negative resistance (FDNR) simulator and two of its applications are presented. The proposed FDNR uses single OTRA and requires five number of passive components; two resistances and three capacitances. The workability of the proposed simulator is demonstrated through the realization of a single resistance controlled oscillator (SRCO) and a fifth order elliptic filter. A detail non-ideality analysis is also done for both FDNR and SRCO. In addition the sensitivity, non-ideality effect and frequency stability analysis of SRCO have been presented. Monte Carlo simulation of the SRCO output has been given and discussed. Moreover, the layout of OTRA, FDNR and SRCO and their post layout simulations in 180 nm are given. PSPICE simulation and experimental results are included to verify theory.

CMOS realization of single-resistance-controlled and variable frequency dual-mode sinusoidal oscillators employing a single DVCCTA with all-grounded passive components

In this paper, two new designs are proposed for sinusoidal oscillators based on a single differential voltage current conveyor transconductance amplifier (DVCCTA). Each of the proposed circuits comprises a DVCCTA combined with passive components that simultaneously provides both voltage and current outputs. The first circuit is a DVCCTA-based single-resistance-controlled oscillator (SRCO) that provides independent control of the oscillation condition and oscillation frequency by using distinct circuit parameters. The second circuit is a DVCCTA-based variable frequency oscillator (VFO) that can provide independent control of the oscillation frequency by adjusting the bias current of the DVCCTA. In this paper, the DVCCTA and relevant formulations of the proposed oscillator circuits are first introduced, followed by the non-ideal effects, sensitivity analyses, frequency stability discussions, and design considerations. After using the 0.35-μm CMOS technology of the Taiwan Semiconductor Manufacturing Company (TSMC), the HSPICE simulation results confirmed the feasibility of the proposed oscillator circuits.

Realization of SRCOs: another new application of DDAs

Since the introduction of differential difference amplifier (DDA) in 1987, several CMOS implementations of the DDA have been evolved, as well as, a number of applications for realizing linear and non-linear functions using DDAs have been reported. However, to the best of authors’ knowledge, any circuit for realizing single-resistance-controlled oscillator (SRCO) using DDAs has not been reported so far. The objective of this paper is to report four new DDA-based SRCOs using DDAs, as another new application of DDAs. The workability of the derived SRCOs has been verified by PSPICE simulation as well as realizing the DDAs by commercially available video differencing amplifier AD830.

OTRA-based Grounded-FDNR and Grounded-Inductance Simulators and Their Applications

New grounded frequency-dependent negative-resistance (FDNR) and grounded inductance simulation circuits, employing an operational trans-resistance amplifier (OTRA) along with two capacitors, two resistors and a voltage follower have been introduced. The application of the new simulators in the realization of a single-resistance controlled oscillator (SRCO) and a single-capacitance controlled oscillator (SCCO) has been demonstrated and the effect of parasitic capacitance and input and output resistances of the OTRA on the performance of these circuits has been evaluated. The workability of the application circuits has been confirmed by experimental results using an OTRA-implemented from commercially available AD844-type current-feedback operational amplifiers (CFOAs).

Low-voltage low-power rail-to-rail low-Rx wideband second generation current conveyor and a single resistance-controlled oscillator based on it

This study presents a novel rail-to-rail second generation current conveyor (CCII) based on quasi-floating gate transistors. The circuit operates at very low supply voltage (±0.5±V), dissipates ultra-low standby power (27±±W), has very high bandwidth ( f -3-dB of 191 and 181 MHz for Ai and Av , respectively) and low input resistance (1.5 ). Most favourably, its total harmonic distortion is 69 dB at an input voltage of 99 of power supply and frequency of 100 KHz. HSPICE simulation results confirm the feasibility and the robustness of the presented CCII against process variations (worst-case parameters) and temperature variation. Performance of this CCII is verified using a low-power grounded-capacitor single resistance-controlled oscillator.

Grounded capacitor current mode single resistance-controlled oscillator using single modified current differencing transconductance amplifier

This study proposes a current mode canonical single resistance-controlled oscillator (SRCO) circuit based on a single modified current differencing transconductance amplifier. The circuit employs grounded capacitors and provides a current output with high output impedance. The proposed circuit also enables orthogonal control of frequency and oscillation condition. The performance of the proposed SRCO is verified by means of simulation program with integrated circuit emphasis (SPICE) simulations, on-chip experiments and measurements.

New FTFN-based grounded-capacitor SRCO with explicit current-mode output and reduced number of resistors

A new current-mode single-resistance-controlled-oscillator (SRCO) using two four-terminal-floating-nullors (FTFNs) is presented. The proposed SRCO provides the following advantageous features, not available simultaneously in any of the FTFN-based grounded-capacitor (GC) SRCOs known earlier so far: (i) use of two GCs which are attractive for IC implementation as well as eliminating/accommodating parasitic capacitances, (ii) very good frequency stability, (iii) low active and passive sensitivities, (iv) independent single grounded resistor control of oscillation frequency (as well as availability of such a control through a resistor ratio), (v) ready availability of explicit current-mode output, and above all, (vi) employment of a reduced number (only four) of resistors, in contrast to earlier two-FTFN-GC SRCOs requiring six resistors. Experimental results are included which confirm the practicability of the proposed circuit.

Identification and design of single amplifier single resistance controlled oscillators

From a unified representation of single amplifier active- RC networks, a set of new single resistance controlled oscillator (SRCO) circuits are identified. These are canonic with respect to the number of capacitors and have minimal component count. A detailed analysis of these circuits has been carried out and the experimental results are given.