Search

In this paper, a differential-input plus-type differential voltage current conveyor-based first-order universal filter is designed. This voltage-mode filter uses a grounded capacitor. In addition, it can provide all the noninverting and inverting first-order universal filter responses. The circuit provides high common-mode rejection ratio of about 76.5 dB. Nevertheless, it needs a single matching problem and comprises two floating resistors. Quadrature oscillator (QO) design is obtained using this filter as an application example. The designed filter and QO circuits are simulated through the SPICE program, and some experimental studies are carried out using AD844 ICs to verify the theory. [ABSTRACT FROM AUTHOR]

In this paper, a CMOS resistor-based current mirror (RBCM) aimed to be used in low-voltage applications is presented. The main features of the proposed current mirror are very low input voltage requirement (a few mV), low output voltage requirement, high output impedance and simple circuitry. The core structure of the proposed RBCM consists of three transistors (excluding bias circuitry) and two low value grounded resistors. The proposed circuit alleviates the need for cascode structures which are conventionally used to boost the output impedance and linearity. SPICE simulations using 0.18m CMOS technology parameters under supply voltage of 0.9V are reported which show input and output voltage requirements of 40mV and 0.1V respectively, low THD of 1.2%, of 496, of 1M, 3dB bandwidth of 181MHz and power dissipation of 154W. A high CMRR differential amplifier and a high performance current difference circuit as applications of the proposed RBCM are given. The proposed RBCM is very useful in tackling restrictions of modern technologies such as reduced supply voltage and transistors low intrinsic output impedance. [ABSTRACT FROM AUTHOR]

In this paper, a new grounded inductor simulator employing two current feedback operational amplifiers (CFOAs), three resistors and one grounded capacitor which is suitable for IC fabrication is proposed. Also, a new voltage-mode (VM) universal filter with three input and single output is given as application example of the grounded inductor simulator. The universal filter with low output impedance can be easily cascaded with other VM circuits. Both of the proposed circuits have the feature of improved low frequency performances, and can be easily constructed by two commercially available active devices such as AD844s. However, both inductor simulator and universal filter need a single passive component matching condition. Simulation and experimental test results are given to demonstrate the performance and workability of the proposed grounded inductor simulator and filter structure. [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]

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. [ABSTRACT FROM AUTHOR]

In this paper, the simplest possible electronically adjustable transresistance-mode (TRM) instrumentation amplifier (IA) using only eight MOS transistors is presented. Extremely simple structure of the proposed IA leads to a wide bandwidth and robust performance against mismatches and parasitic capacitances. Of more interest is that the differential-mode gain of the proposed IA can be electronically varied by control voltages. Post-layout and pre-layout simulation results based on 0.18m TSMC CMOS parameters are included to confirm the validity of the theoretical analysis. Despite extremely simple structure, its input and output impedances are 1.93 and 1.68k, respectively. Time domain analysis shows that for an input signal of 20A peak to peak, maximum value of THD is 4.5% for different frequencies. Monte Carlo simulation is also carried out, which proves robust performance of the proposed IA against mismatches. The required chip area is only . [ABSTRACT FROM AUTHOR]

In this paper, a novel first-order current-mode (CM) electronically tunable all-pass filter including one grounded capacitor and two dual-output current followers (DO-CFs) is presented. The used DO-CFs are implemented using only 10 MOS transistors granting the proposed CM all-pass filter extremely simple structure. The proposed filter is suitable for integrated circuit (IC) fabrication because it employs only a grounded capacitor and is free from passive component matching conditions. Interestingly the introduced configuration uses minimum number of components compared to other works. It also offers other interesting advantages such as, alleviating all disadvantages associated with the use of resistors, easy cascadability and satisfies all technology requirements such as small sizing, simple realization, low voltage and low power operation. Additionally, the circuit parameters can be easily set by adjusting control voltages. Most favorably, the proposed CM all-pass filter can be simply used as a voltage-mode (VM) all-pass filter with outstanding properties of adjustable gain and tunability. To further show the versatility of the proposed structure a sinusoidal oscillator is also derived from presented CM all-pass filter. Nonideal gain and parasitic impedance effects on developed CM filter are discussed. Finally, simulation results with SPICE program are included to confirm the theory. [ABSTRACT FROM AUTHOR]

In this work, a wideband and high-performance CMOS implementation of 2nd-generation current conveyor (CCII) is proposed. The proposed circuit is composed of a high performance voltage follower stage which is based on differential pairs to provide high voltage swings on input and output ports and a current follower stage. It is shown that the proposed voltage follower stage can be used to implement high performance 1st and 3rd-generation current conveyors (CCI and CCIII, respectively) that have very small equivalent impedances on ports X, high equivalent impedances on ports Y and Z and also high-valued voltage and current transfer bandwidths. 2nd and 3rd order filter circuits as well as a half-wave rectifier circuit are given to show the performance and usefulness of the proposed current conveyor circuits. The simulation and experimental results are given to verify the theoretical analyses. [ABSTRACT FROM AUTHOR]

In this paper, a new current-mode (CM) circuit for realizing all of the first-order filter responses is suggested. The proposed configuration contains low number of components, only two NMOS transistors both operating in saturation region, two capacitors and two resistors. Major advantages of the presented circuit are low voltage, low noise and high linearity. The proposed filter circuit can simultaneously provide both inverting and non-inverting first-order low-pass, high-pass and all-pass filter responses. Computer simulation results achieved through SPICE tool and experimental results are given as examples to demonstrate performance and effectiveness of the proposed topology. [ABSTRACT FROM AUTHOR]

This work presents a high-slew rate rail-to-rail buffer amplifier, which can be used for flat panel displays. The proposed buffer amplifier is composed of two transconductance amplifiers, two current comparators and a push-pull output stage. Phase compensation technique is also used to improve the phase margin value of the proposed buffer amplifier for different load capacitances. Post-layout simulations of the proposed buffer amplifier are performed using 0.35 μm AMS CMOS process parameters and 3.3 V power supply. The circuit is tested under a 600 pF capacitive load. An average settling time of 0.85 μs under a full voltage swing is obtained, while only 3 μA quiescent current is drawn from the power supply. Monte Carlo analysis is also added to show the process variation effects on the circuit. [ABSTRACT FROM AUTHOR]

In this paper, a grounded voltage controlled resistor (GVCR) employing eight CMOS transistors, all of which are operating in saturation region, is proposed. The developed GVCR has two identical control voltages in opposite sign for electronically changing the resistance value. The linearity of the current-voltage (I - V) characteristic of the proposed GVCR is not affected by the body effect of the transistors. Computer simulation results with SPICE program are given to exhibit the performance and effectiveness of the introduced GVCR. [ABSTRACT FROM AUTHOR]

In this paper, an electronically tunable current-mode (CM) universal biquad filter is proposed. The proposed filter employs three dual-X second-generation current conveyors (DXCCIIs), two grounded capacitors and four NMOS transistors acting as resistors. The proposed filter simultaneously realizes standard filter functions such as low-pass (LP), band-pass (BP), and high-pass (HP) responses. The notch (NH) and all-pass (AP) functions can also be obtained by connecting appropriate output currents directly without using additional active elements. The output signals are obtained at high output impedance terminals, which is important for easy cascading in CM operation. SPICE simulation results are given to verify the theoretical analyses. [ABSTRACT FROM AUTHOR]

In this paper, a new current-mode (CM) all-pass filter employing two Dual-Output Second-Generation Current Conveyors (DO–CCIIs), one grounded resistor and one grounded capacitor is presented. The proposed circuit exhibits low input impedance and high output impedance, which makes it suitable for cascading. Moreover, adding two extra resistors to the proposed circuit, a new gain-variable voltage-mode (VM) all-pass filter is obtained. A quadrature oscillator employing minimum number of grounded passive components is derived from the developed CM filter as an application of the first-order all-pass filter. Both of the proposed all-pass filters do not require matching of passive components. The effects of the parasitic impedances of the DO–CCIIs on the transfer function (TF) of the proposed CM filter as an example are investigated. In addition, the proposed CM all-pass filter and oscillator circuit are simulated using SPICE simulation program to confirm the theory. [ABSTRACT FROM AUTHOR]

In this paper, a novel circuit for realizing voltage-mode first-order and second-order all-pass filter responses as well as second-order notch filter response depending on the passive component choice, is presented. This circuit has high input impedance; thus, it is easy to cascade the introduced filter with other voltage-mode topologies. Also, it uses a single Variable Gain Current Conveyer — VGCCII and only grounded capacitors. SPICE simulation results based on 0.35 μm TSMC CMOS technology parameters are given to confirm the theory. [ABSTRACT FROM AUTHOR]

In this paper, an active-C circuit for realizing lossless floating inductor (FI) or series/parallel R–L impedances depending on the externally applied bias currents, is presented. The proposed simulator circuit employs only three plus-type second-generation current controlled conveyors (CCCII+s) as active elements and a single capacitor as passive element. SPICE simulation and experimental results are given to verify the theory. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

A general configuration suitable for realizing low-pass and high-pass ladder filters and transformer simulator, depending on the passive element selection is proposed. The proposed network employs only grounded passive components without requiring matching conditions. The values of the synthetic inductances of the transformer and low-pass ladder filter can be changed independently. SPICE simulation results confirming the theoretical analysis are included. [ABSTRACT FROM AUTHOR]

In this paper, a floating inductance and frequency-dependent negative resistance (FDNR) depending on the passive element selection is presented. The proposed circuit employs only plus-type second-generation current conveyors (CCII+s) as active elements, together with two resistors and two capacitors for realizing floating inductance and FDNR. Both of the capacitors in the floating inductance realization are grounded. Also, electronically tunable floating FDNR is obtained with the proposed circuit. The nonideality effects of the current conveyors on the proposed circuit are given. The proposed circuit is used in a low-pass ladder filter, and simulated with SPICE to exhibit its performance. [ABSTRACT FROM AUTHOR]