Parasitic-capacitance-insensitive voltage-mode mosfet-C filters using differential current voltage conveyor

A new CMOS realization of the differential current voltage conveyor (DCVC) is introduced. The properties of the DCVC are shown to be suitable for very large-scale integration applications employing metal oxide semiconductor transistors operating in an ohmic region. A novel voltage-mode integrator is introduced. Detailed analysis of the parasitic capacitances is included. Voltage-mode continuous-time filters that benefit from the current processing capabilities at the input terminals of the DCVC are presented. Self-compensation of the proposed circuits is also presented. The effectiveness of the proposed circuits is demonstrated through HSPICE simulations based on the AMI 1.2m N-well level 3 parameters.     

Insensitive voltage-mode and current-mode filters with easily modifiable transfer functions

Two configurations for 2^nd order current-mode filters are introduced. The circuits, which exhibit low values for their active and passive sensitivies are implemented from two current conveyors. They are easily cascadable because they exhibit zero input impedance. Two voltage-mode implementations are then deduced from them. Depending on the passive components used, the circuit will be either a 2^nd order or a 3^rd order filter. Both the current-mode and voltage-mode implementations are characterized by easily modifiable transfer functions, without affecting ₀ and Q.SPICE simulation results, which confirm the theoretical analysis, are given and discussed for current conveyors implemented in a translinear form.     

A new approach for the realization of voltage-mode second-order universal filters using current conveyors

In this work two different types of topologies are derived for realization any second-order filter characteristic by choosing properly, the admittances of passive elements. These topologies use two second-generation current conveyors (CCIIs). One of the topologies involves different types of CCIIs whereas the other uses the same type of CCIIs together with a unity gain voltage buffer. The buffer used provides not only low output impedance but also facilitates cascading of the filter circuits thus obtained. It is possible to derive many different filters realizing any second-order transfer function by the use of the proposed topologies. Moreover, the produced filters have low-sensitivity performance and permit orthogonal controlling of both the quality factor and the natural angular frequency.     

High input impedance voltage-mode universal biquadratic filters with three inputs using plus-type CCIIs

Two new configurations for realizing high input impedance voltage-mode universal biquadratic filters are presented. Each proposed universal biquadratic filter with three inputs is composed of three plus-type CCIIs and can realize all the standard filter functions, that is, highpass, bandpass, lowpass, notch and allpass filters. In spite of the active components, the first proposed configuration uses five passive components, the second proposed configuration uses three capacitors and three resistors. The use of only plus-type CCIIs simplifies the configurations.     

Insensitive current-mode universal filter using dual output current conveyors

A new current-mode universal filter with single input and three outputs employing only three dual output current conveyors and five grounded passive elements is presented. The proposed filter realizes three filter functions simultaneously, all at high impedance outputs. No component matching is required and all the passive and active sensitivities are low. Furthermore, the filter can also realize the notch and all-pass responses. Orthogonal control of the natural angular frequency and the quality factor is achieved.     

Multifunction mixed-mode filter using FTFNs

A novel mixed-mode multifunction filter configuration containing three FTFNs and only five passive components with a single input and three different outputs is presented. The configuration can be driven by a voltage or current source while as outputs are always voltages and currents. The circuit can thus realize filtering functions in normal-mode as well as in mixed-mode. Besides having small active and passive sensitivities, the parameters resonance frequency (ω₀) and bandwidth (ω₀/Q) enjoy orthogonal tuning. The theoretical results are verified by PSPICE simulations.     

Insensitive grounded-capacitor simulation of grounded inductors using current conveyors

Two new schemes for grounded-inductor simulation with single grounded capacitors using the second-generation current conveyors (c.c. II) are reported. The realised inductors L and their quality factors Q can be independently adjusted and hence are suitable for high-quality applications. L and Q are shown to be quite stable and are practically insensitive to the changes in the active c.c. II parameters.     

The effects of CCII non-idealities on voltage-mode active filters

In active filters, the performance of the active element plays an important role in the overall performance of the filter, besides the filter configuration itself. In this paper, we will investigate the effects of current conveyor non-idealities on a certain class of filters which consists of four current conveyors and seven nodes, and derive analytical expressions for the filter parameter deviations in terms of non-ideality terms. The results obtained apply to all filters under this class which are considerable in number. This will enable us to determine the requirements for the current conveyor non-ideality terms in order to obtain a specified filter performance. A comparable demonstration of the filter transfer functions for two example current conveyor circuits will be given. Simulations including three types of filters, namely, the bandpass, lowpass and highpass filters, confirm the analytical expressions obtained.     

Universal active current filters using single second-generation current conveyor

Two novel universal active current filters, one of which has multiple outputs and the other of which has a single output and high output impedance, employing a single negative second-generation current conveyor, three position-fixed capacitors and four/five position-fixed resistors are proposed. The proposed networks with the advantages of low passive sensitivities can obtain second-order lowpass, bandpass, highpass, notch and allpass current signals by adjusting the magnitudes of a grounded resistor and a grounded capacitor provided that another resistor is separable. The resonance angular frequency and quality factor are insensitive to the current tracking error of the nonideal CCII.<>     

Universal active current filters using single second-generation current conveyor

Two novel universal active current filters with a single second-generation current conveyor (CCII), which use fewer passive RC elements and have a larger quality factor than the previous two filters proposed by the author, are presented.<>     

Single-resistance-controlled sinusoidal oscillator using two FTFNs

A new single-resistance-controlled sinusoidal oscillator using two four-terminal floating nullors (FTFNs) is presented. The proposed oscillator has good frequency stability, single-element-controlled ability and low passive and active sensitivities. Moreover, this oscillator needs only grounded capacitors and its oscillation frequency can be independently controlled by a grounded resistor. Experimental results are given to verify the theoretical analysis     

All-pass filters using a single current conveyor

Current conveyors are unity gain active elements exhibiting high linearity, wide dynamic range and better high frequency performance compared with their voltage mode counterparts. In this study a set of single positive-type second generation current conveyor based all-pass filters is presented and a catalogue of canonical topologies is given with some properties in tabular form. In contrast with single topology presentations, 22 different topologies are presented which exhibit identical transfer functions but differ in the number of passive components, component matching constraints, possibility of gain adjustment and other properties.     

NOVEL SECOND-ORDER CURRENT MODE FILTERS USING CCIIs

Two new current mode active-RC networks using the second generation current conveyer (CCII) devices are presented. The circuits provide high-Q bandpass (BP)/lowpass(LP) filter characteristics; the highpass(HP) response may also be obtained with suitable design. Current mode sine wave signal generation (Q→α) is possible by tuning a grounded resistor. With non-ideal CCIIs the design equations are slightly altered owing to CCII port current and voltage tracking errors (Ei,v).     

Multiple-loop feedback filters using current feedback amplifiers

Novel high-order filter topologies realised by employing current feedback operational amplifiers as active elements are introduced in this article. These are constructed from multiple-loop feedback paths and could be utilised for the realisation of filters of arbitrary order and type. An offered benefit is the requirement for employing only grounded capacitors and resistors. Two design examples are provided and the correct operation of the corresponding topologies has been evaluated through experimental results.     

Universal biquad filters using low-voltage current mirrors

Novel Single Input Multiple Output (SIMO) and Multiple Input Single Output (MISO) current-mode universal biquad topologies are introduced in this paper. The proposed topologies have been realized by employing low-voltage current mirrors as active elements. As a result, an absence of resistors is achieved in the derived filter topologies; also only grounded capacitors are required. The resonant frequency of the filters can be electronically controlled by an appropriate dc current. In addition, the derived filters offer the feature of orthogonal adjustment between the resonant frequency and Q factor. The behavior evaluation of the proposed filters has been performed through a test chip prototype fabricated in AMS 0.35 μm CMOS technology.     

Allpass filters using a current-controlled current source

Two allpass filter realisations, using a current-controlled current source (CCCS) as the active element, are reported. Their performances are discussed. Experimental results, which confirm the validity of the theoretical analysis, are given for the two configurations.     

Current-mode continuous-time filters using complementary current mirror pairs

A design of current-mode continuous-time filters for low voltage and high frequency applications using complementary bipolar current mirror pairs is presented. The proposed current-mode filters consist of simple bipolar current mirrors and capacitors and are quite suitable for monolithic integration. Since the filters are based on the integrator type of realization, the proposed method can be used for a wide range of applications. The frequency of the filters can easily be changed by the DC controlling current. A fifth-order Butterworth and a third-order leapfrog filter with tunable cutoff frequencies from 20 MHz to 100 MHz are designed as examples and simulated by SPICE using standard bipolar parameters.     

Universal voltage-mode filter using only plus-type DDCCs

Despite the extensive literature on current conveyor-based voltage-mode universal biquads with single input and multiple outputs, no filter circuit has been reported to simultaneously achieve all of the advantageous features: (i) employment of only two differential difference current conveyor (DDCC), (ii) employment only two grounded capacitors, (iii) employment only three resistors, (iv) simultaneously realize voltage-mode low-pass, band-pass, high-pass, notch and all-pass filter signals from the five output terminals, respectively, (v) orthogonal control of ω _o and Q, (vi) low input impedance and can be cascadable (vii) no need to employ inverting type input signals, and (viii) no need to impose component choice except realizing the all-pass filter signal.     

Realisation of voltage-mode biquads using CCIIs

A method for realising biquadratic transfer functions using current conveyors (CCIIs) is presented, and two novel networks which realise the general second-order transfer function are given. The networks are composed of solely plus-type CCIIs with grounded capacitors, and offer high input impedances.<>     

Design of voltage-mode PID controller using a single voltage differencing current conveyor (VDCC)

Analog Integrated Circuits and Signal Processing - This paper presents a voltage differencing current conveyor (VDCC) based voltage-mode (VM) proportional integral derivative (PID) controller for...