Tunable versatile current-mode universal filter based on plus-type DVCCs

This paper presents a new tunable versatile current-mode universal filter with four inputs and three outputs. The proposed configuration employs three plus-type differential voltage current conveyors, two grounded capacitors and three grounded resistors. Its high impedance outputs enable easy cascading in current-mode operation. The circuit can be used as either a single-input and three-output or four-input and two-output. In the operation of single-input and three-output circuit, the bandpass, highpass and bandreject filtering responses can be realized simultaneously. In the operation of four-input and two-output circuit, both inverting and non-inverting type lowpass, bandpass, highpass, bandreject and allpass filtering responses can be simultaneously realized by selecting different four input current signals. The filter permits orthogonal controllability of the quality factor and resonance angular frequency by adjusting the grounded passive components. No component matching condition is required for realizing all the filter responses, and all the passive and active sensitivities are low. HSPICE simulation results based on using TSMC 0.18 μm 1P6M CMOS process technology and supply voltages ±0.9 V to verify the theoretical analysis.     

Versatile universal voltage-mode filter employing DDCCs

A new versatile universal voltage-mode biquad with three inputs and five outputs using only two differential difference current conveyors (DDCCs), two grounded capacitors, and three resistors is proposed. The proposed configuration which can be used as either a single-input five-output filter or three-input two-output filter and which can simultaneously realize all five different generic filtering lowpass, bandpass, highpass, bandstop, and allpass signals is unlike the previously reported works and still enjoys (i) the employment all grounded capacitors, (ii) no need to employ inverting-type input signals, (iii) orthogonal control of the resonance angular frequency and the quality factor, (iv) simultaneous realization of lowpass, bandpass, highpass, bandstop, and allpass responses for the single-input five-output filter, and (v) no need to impose component choice to realize all five generic responses for the three-input two-output filter.     

Versatile multifunction universal voltage-mode biquadratic filter

A new versatile multifunction universal biquadratic filter with four inputs and four outputs employing one differential difference current conveyor, one full differential current conveyor, two grounded capacitors and two grounded resistors is proposed. The proposed configuration can be used as either three-input single-output voltage-mode universal filter with high-input and low-output impedance or single-input four-output voltage-mode multifunction filter with high-input impedance. It still maintains the following advantages: (i) the employment of only two current conveyors, (ii) the employment of only grounded capacitors, (iii) the employment of only grounded resistors, (iv) no need to employ inverting type input signals, (v) no need to impose component choice conditions to realize specific filtering functions and (vi) low active and passive sensitivity performances.     

A Modified CFOA and Its Applications to Simulated Inductors, Capacitance Multipliers, and Analog Filters

In this paper, using a minimum number of passive components, i.e., new grounded and floating inductance simulators, grounded capacitance multipliers, and frequency-dependent negative resistors (FDNRs) based on one/two modified current-feedback operational amplifiers (MCFOAs), are proposed. The type of the simulators depends on the passive element selection used in the structure of the circuit without requiring critical active and passive component-matching conditions and/or cancellation constraints. In order to show the flexibility of the proposed MCFOA, a single-input three-output (SITO) voltage-mode (VM) filter, two three-input single-output (TISO) VM filters, and an SITO current-mode (CM) filter employing a single MCFOA are reported. The layout of the proposed MCFOA is also given. A number of simulations using the SPICE program and some experimental tests are performed to exhibit the performance of the introduced structures.      

Electronically tunable current-mode biquad filter employing CCCDTAs and grounded capacitors with low input and high output impedance

In this study, a single-input multiple-outputs current-mode analog biquadratic filter, based on current controlled current differencing transconductance amplifier (CCCDTA) is presented. The proposed filter uses two CCCDTAs and two grounded capacitors without any external resistors, which is well suited for integrated circuit implementation. The filter simultaneously gives 3 standard transfer functions, namely, lowpass, highpass and bandpass filters with independent control of quality factor and pole frequency by electronic method. By summing of I_HP and L_LP, the notch filter can be also achieved. Moreover, the circuit has low input and high output impedance which would be an ideal choice for cascading in current-mode circuit. The PSPICE simulation results are included verifying the workability of the proposed filter. The given results agree well with the theoretical anticipation.     

Voltage mode universal filters employing single FDCCII

In this paper, four new voltage-mode universal biquad filters configuration are proposed. First of two circuits proposed high-input impedance universal filter with single-input and three-outputs, which can simultaneously realize voltage mode low-pass, band-pass and high-pass filter responses employing all grounded passive components. The third proposed universal filter three-input and single-output, which also can realize all the standard filter functions. The fourth circuit proposed universal filter with three-input and five-outputs, which can be used as either a three-inputs single-output or a two-inputs five-outputs universal filters. It can realize all five different generic filtering signals: low-pass, band-pass, high-pass, band-stop and all-pass. Simulation results are given to confirm the theoretical analysis. The proposed biquad filters are simulated using TSMC CMOS 0.35 μm technology.     

All-Grounded Passive Elements Voltage-Mode DVCC-Based Universal Filters

In this paper two new voltage-mode (VM) universal filters employing three plus-type differential voltage current conveyors (DVCC+s) and grounded passive elements are presented. The first proposed filter is a single-input five-output (SIFO) circuit which can realize simultaneously all of the standard responses, i.e. low-pass (LP), band-pass (BP), high-pass (HP), all-pass (AP) and notch (NH) from the same configuration. The second proposed circuit is a three-input single-output (TISO) universal filter for realizing standard responses depending on the selection of the input signal from the same topology. Both of the proposed filters have the advantage of a high input impedance, which enables easy cascading to obtain higher order filters. The proposed filters are simulated using the SPICE program to verify the theoretical analysis.     

High output impedance current-mode universal biquadratic filters with five inputs using multi-output CCIIs

Three current-mode universal biquadratic filters each with five input terminals and one output terminal are presented. The first proposed circuit uses three multi-output second-generation current conveyors, two grounded capacitors and three resistors. This circuit offers the following advantageous features: orthogonal controllability of resonance angular frequency and quality factor, high output impedance, the versatility to synthesize all standard filter types without component matching condition and using grounded capacitors. The second proposed circuit uses three multi-output second-generation current conveyors, two grounded capacitors and two resistors. This circuit offers the following advantageous features: using minimum passive components, high output impedance, the versatility to synthesize all standard filter types without component matching condition and using grounded capacitors. The third proposed circuit uses three multi-output second-generation current conveyors, two grounded capacitors and three grounded resistors. This circuit offers the following advantageous features: the versatility to synthesize all standard filter types, high output impedance and using only grounded passive components. Each of the proposed circuits can get five kinds of filter functions by using only one current input signal.     

Multiple-input single-output low-input and high-output impedance current-mode biquadratic filter employing five modified CFTAs and only two grounded capacitors

This paper presents a novel current-mode biquadratic filter with three inputs and a single output. The proposed circuit employs five modified current follower transconductance amplifiers (MCFTAs) and only two grounded capacitors. It can realize all five biquadratic filter functions namely: low-pass (LP), band-pass (BP), high-pass (HP), band-stop (BS) and all-pass (AP) at the output terminal by selecting different input current signals, without requiring any parameter-matching conditions or additional circuits. The filter has an orthogonal electronic adjustment of the natural angular frequency ω₀ and the quality factor Q, and it has very low element sensitivities of ω₀ and Q. Moreover, the proposed filter has the feature of high output impedance and low input impedance, and the use of only grounded capacitors makes it convenient for integrated circuit implementation. The performances of the proposed circuit are illustrated by PSPICE simulations, and the results are in good agreement with theoretical analysis.     

Electronically tunable versatile voltage-mode universal filter

A novel electronically tunable versatile voltage-mode universal biquad filter by using two single-output-operational transconductance amplifiers (OTAs), one differential difference current conveyor (DDCC) and two capacitors is proposed. The proposed circuit, which can be used as either a four-input single-output universal filter or a single-input three-output multifunction filter with the same topology. Besides, the new circuit offers the following advantageous features: realization of all the non-inverting and inverting biquadratic filter signals from the same configuration, no need to employ inverting-type input signals, no need to component-matching conditions and low passive sensitivity performance.     

ICCII-based universal current-mode analog filter employing only grounded passive components

In this paper, three versions of a novel second-order current-mode (CM) single-input three-output analog filter employing inverting second-generation current conveyors (ICCIIs) and only grounded passive components, are presented. This filter can simultaneously realize low-pass, band-pass and high-pass responses, and can also realize notch and all-pass filter responses with interconnection of the relevant output currents. The presented second-order filter requires no active and passive element matching conditions and/or cancellation constraints. The proposed filter offers orthogonal control of angular resonance frequency (ω_o) and quality factor (Q). The proposed filter can realize filter responses at high output impedances, and has low active and passive component sensitivities. Additionally, three versions of a high-order filter derived from the proposed filter are introduced. Simulation results using SPICE program are given to show the performance of the filter and verify the theory. Signal limitations and non-ideal current and voltage gain effects of the proposed second-order filter are also investigated.     

Novel versatile insensitive universal current-mode biquad employing two second-generation current conveyors

A new universal current-mode biquad with two inputs and three outputs or three inputs and two outputs using only two second-generation current conveyors and four grounded/virtual-grounded passive elements is proposed. The proposed circuit has the following advantages: simultaneous realization of five generic current-mode filter signals from the same configuration; no requirements of any cancellation constraints; employment of two grounded capacitors ideal for integrated circuit implementation; employment of two grounded/virtually grounded resistors suitable for voltage control; orthogonal adjustment of ω₀/Q and ω₀ through two separate grounded/virtually-grounded resistors; high output impedance good for cascadability for the current-mode circuits; and low active and passive sensitivities.     

SITO electronically tunable high output impedance current-mode universal filter

A novel current-mode (CM) single-input and three-output (SITO) universal filter using two second generation current controlled conveyors (CCCIIs), one current follower (CF) and two capacitors is presented. The circuit is fully programmable and implements all the five generic filtering functions. The lowpass (LP), bandpass (BP), and highpass (HP) functions can be realized simultaneously while Notch (BS) and allpass (AP) responses can be implemented simply by connecting the appropriate node currents without requiring additional elements. The availability of currents at high impedances, facilitate cascadibility feature. The filter performance factors ω₀ and ω₀/Q are electronically tunable through separate bias currents of the CCCIIs. SPICE simulation results are included to confirm the workability of the proposed circuit.     

基于CC多输入单输出电流模式滤波器

为了实现结构简单、便于集成的三输入单输出电流模式滤波器,提出了三输入单输出电流模式滤波器的信号流图。用CC(第二代电流传输器)及多端输出的电流镜实现了该信号流图,得到一个由CC及电流镜共同构成的电流模式滤波器。该滤波器由2个CC、1个三端输出的电流镜及4个RC元件构成,能方便地实现5种滤波器输出。该滤波器可用于通信、电子测量与仪器仪表中的信号处理。硬件实验结果表明提出的电路是正确的。     

Insensitive current-mode universal filter with minimum componentsusing dual-output current conveyors

A novel universal current-mode active filter with four inputs and one output is presented, which contains only three dual-output current conveyors. Two grounded capacitors and two grounded resistors. The circuit is very advantageous from an integration point of view. The proposed active filter realises all filter responses without any matching conditions at high impedance output and has low passive and active sensitivities     

Voltage-mode FDCCII-based universal filters

Three new voltage-mode universal biquadratic filters configuration are proposed. The first proposed high-input impedance universal filter with single input and five outputs, which can simultaneously realize voltage-mode lowpass (LP), bandpass (BP), highpass (HP), bandstop (BS) and allpass (AP) filter responses employing all grounded passive components. The second proposed high-input impedance universal filter with three input and single output, which also can realize all the standard filter functions without requiring any inverting input voltage signal. The third proposed universal filter with three inputs and five outputs, which can be used as either a three-input single-output or a two-input five-output universal filter. Moreover, each of the proposed circuits still enjoys (i) the employment of only grounded capacitors, and (ii) no requirement with the component choice conditions to realize specific filtering functions.     

Electronically controlled high input and low output impedance voltage mode multifunction filter with grounded capacitors

In this study, a three-input single-output voltage-mode biquadratic filter employing voltage differencing differential input buffered amplifier (VD-DIBA) is presented. The proposed filter uses two VD-DIBAs and two grounded capacitors without any external resistors, which is well suited for integrated circuit implementation. The circuit provides five standard transfer functions, namely, low pass, high pass, band pass, notch and all pass filters with electronic control of quality factor and pole frequency. Each transfer function can be selected by suitably selecting input signals via digital method. The filter does not require inverting of the input voltage signal. Moreover, the circuit possesses high input and low output impedances and thus it enables simple voltage-mode cascading. The PSPICE simulation and also experimental results are included, verifying the workability of the proposed filter. The given results agree well with the theoretical anticipation.     

High Output Impedance Current-Mode Four-Function Filter with Reduced Number of Active and Passive Elements Using the Dual Output Current Conveyor

This paper reports a new single-input multi-output current-mode multifunction filter which can simultaneously realise LP, HP, BP and BR filter functions all at high impedance outputs. The circuit permits orthogonal adjustment of quality factor Q and ₀, employs only five grounded passive components and no element matching conditions are imposed. A second order all-pass function can easily be obtained. The passive sensitivities are shown to be low.     

Single-input and three-output current-mode universal filter using areduced number of active elements

A new single-input and three-output current-mode universal filter, using only four operational mirrored amplifiers, is presented. It is shown that the filter is better than existing current conveyor-based universal current filters. Experimental results verifying the theoretical analysis are also included