Single-input four-output voltage-mode universal filter using single DDCCTA

An electronically tunable universal voltage-mode biquadratic filter with single input and four outputs using one differential difference current conveyor transconductance amplifier (DDCCTA), two resistors and two grounded capacitors is proposed. All the five standard biquadratic filter functions; lowpass (LP), bandpass (BP), highpass (HP), bandstop (BS) and allpass (AP), can be obtained from the circuit configuration. The LP, BP and HP are simultaneously available without component matching condition. By imposing component choice, the BS and AP responses can also be realized from the same circuit configuration. In addition, the proposed circuit provides an electronic control of its natural angular frequency (ω₀) and quality factor (Q) by adjusting the bias current of the DDCCTA. The simulation results together with the ideal values are also given to demonstrate the performance of the proposed circuit.     

Novel current-mode biquadratic circuit using only plus type DO-DVCCs and grounded passive components

This paper introduces a novel current-mode biquadratic circuit using plus type differential voltage current conveyors (DVCCs) and grounded passive components. The circuit is constructed with two plus type dual current output DVCCs (DO-DVCCs), two grounded capacitors and two resistors. The circuit can realize multiple circuit transfer functions by choosing the appropriate input and output terminals. Additionally, the circuit parameters Q and ω ₀ can be set orthogonally by adjusting the passive components. The biquadratic circuit enjoys very low sensitivities to the circuit components. An example is given together with simulated results by PSPICE.     

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.     

High Input Impedance Voltage-Mode Universal Biquadratic Filter with One Input and Five Outputs Using Current Conveyors

A new high input impedance voltage-mode universal biquadratic filter with one input terminal and five output terminals is presented. The proposed circuit uses three differential voltage current conveyors (DVCCs), four resistors, and two grounded capacitors. The proposed circuit can realize all the standard filter functions—lowpass, bandpass, highpass, notch, and allpass—simultaneously, without changing the passive elements. The proposed circuit enjoys the features of high input impedance, orthogonal control of resonance angular frequency and quality factor, use of only grounded capacitors, and low active and passive sensitivities.     

High Input Impedance Voltage-Mode Universal Biquadratic Filter with Three Inputs Using DDCCs

A new high input impedance voltage-mode universal biquadratic filter with three input terminals and five output terminals is presented. The proposed circuit uses three plus-type differential difference current conveyors, two grounded resistors and two grounded capacitors. The proposed circuit can realize all the standard filter functions: lowpass, bandpass, highpass, notch and allpass, without component matching conditions. The proposed circuit offers the features of high input impedance, low active and passive sensitivities and the use of only grounded resistors and capacitors.     

High Input Impedance Voltage-Mode Universal Biquadratic Filter with Three Inputs and Six Outputs Using Three DDCCs

A new high input impedance voltage-mode universal biquadratic filter with three input terminals and six output terminals is presented. The proposed circuit uses three plus-type differential difference current conveyors (DDCCs), three resistors, and two grounded capacitors. The proposed circuit can realize all the standard filter functions, namely, lowpass, bandpass, highpass, notch, and allpass, simultaneously, without component matching conditions. The proposed circuit still offers the features of high input impedance, using only grounded capacitors, and orthogonal controllability of resonance angular frequency and quality factor.     

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.     

Versatile current-mode biquadratic circuit using only plus type CCCIIs and grounded capacitors

This paper introduces a versatile current-mode biquadratic circuit using second generation current-controlled current conveyors (CCCIIs). The circuit is constructed with two plus type multiple current output CCCIIs (MO-CCCIIs) and two grounded capacitors. The circuit can realize low-pass, band-pass, high-pass, band-stop and all-pass transfer functions by choosing appropriate input and output terminals without any component matching conditions. Additionally, the circuit parameters Q and ω₀ can be set orthogonally by adjusting the bias currents of the MO-CCCIIs and grounded capacitors. The biquadratic circuit enjoys very low sensitivities to the circuit components.

Some examples are given together with simulated results by PSPICE.     

Electronically tunable current-mode biquadratic filter and four-phase quadrature oscillator

This paper presents a current-mode biquadratic filter based on ZC-CFTAs. It employs only three ZC-CFTAs, one resistor and two grounded capacitors. It can simultaneously realize not only highpass and lowpass filtering functions but also two different forms of bandpass ones; one has a pass-band gain of Q, the other, a pass-band gain of unity. Its ω_o and Q can be tuned orthogonally through adjusting bias currents of ZC-CFTAs. Moreover, the proposed circuit can also be modified to be a current controlled four-phase quadrature oscillator with small distortion. Non-ideal analysis and sensitivity analysis are provided. The results of circuit simulations are in agreement with theory.     

Voltage-mode universal filter with one input and five outputs using DDCCTAs and all-grounded passive components

This paper presents a versatile voltage-mode universal active filter with one input and five output terminals. The proposed circuit is based on using the recently reported active building block, namely differential difference current conveyor transconductance amplifier (DDCCTA). It employs two DDCCTAs as active elements together with two resistors and two capacitors as passive elements, which are all grounded. The circuit simultaneously realizes all the five standard biquadratic filter functions; i.e., lowpass (LP), bandpass (BP), highpass (HP), bandstop (BS) and allpass (AP), without changing circuit topology. The proposed circuit also has the advantage of high-input impedance terminal, and exhibits electronic tunability of its important parameters through the bias current of the DDCCTA as well as low sensitivity performance. PSPICE simulations using 0.5 μm MIETEC CMOS process are used to validate the theoretical predictions.     

Electronically tunable high-input impedance voltage-mode universal biquadratic filter based on simple CMOS OTAs

This paper describes a new electronically tunable three inputs and single output voltage-mode universal biquadratic filter based on simple CMOS operational transconductance amplifiers (OTAs) and grounded capacitors. The proposed configuration provides lowpass, highpass, bandpass, bandstop and allpass voltage responses at a high impedance input terminal, which enable easy cascadability. Additionally, the circuit parameters ω_o${\omega }_o$ and Q   can be set orthogonally by adjusting the transconductances and grounded capacitors. The filter also offers an independent electronic control of parameters ω_o${\omega }_o$ by adjusting the transconductance through the bias current/voltage of the OTA. For realizing all the filter responses, no critical component matching condition is required, and all the incremental parameter sensitivities are low. PSPICE simulation results are performed to confirm the theoretical analysis.     

Compact VDTA-based current-mode electronically tunable universal filters using grounded capacitors

This paper presents a compact current-mode three-input single-output (TISO) type universal filter. Only one voltage differencing transconductance amplifier (VDTA) and two grounded capacitors are employed in the proposed filter. The circuit can realize lowpass, bandpass, highpass, bandstop and allpass biquadratic filter outputs by connecting the appropriate inputs, and offers electronic control of the natural angular frequency (ω₀) and quality factor (Q) by means of adjusting the transconductance gain of the VDTA. In addition, by slight modification of the proposed scheme, another more useful TISO construction with orthogonal ω₀–Q tuning has been obtained. Both the discussed universal filters have been shown to have low incremental active and passive sensitivities. To demonstrate the performances of the filters and verify the theoretical analysis, computer simulations are accomplished with the PSPICE program.     

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.     

New electronically tunable current-mode universal biquad filter using translinear current conveyors

In this study, a new electronically tunable current-mode universal filter with two inputs and two outputs employing one translinear current conveyor, one translinear current conveyor with controlled current gain and two grounded capacitors is presented. The proposed circuit offers the following attractive features: realisation of low-pass, band-pass, high-pass, band-stop and all-pass current responses from the same configuration; employment of the minimum active and passive components; no requirement of component matching conditions; independent current-control of the parameters natural frequency (ω_o) and quality factor (Q); low active and passive sensitivities; and high impedance output. The characteristics of the proposed circuit are simulated using PSPICE to confirm the theory.     

Current-Mode Universal Biquadratic Filter with Five Inputs and Two Outputs Using Two Multi-Output CCIIs

A current-mode universal biquadratic filter with five input terminals and two output terminals is presented. The proposed circuit uses two multi-output second generation current conveyors, two grounded capacitors and three resistors. The new circuit offers the following advantages: use of the minimum number of active components, orthogonal controllability of resonance angular frequency and quality factor, use of grounded capacitors and the versatility to synthesize any type of active filter transfer functions.     

Single FDCCII-based mixed-mode biquad filter with eight outputs

The transconductance and the transresistance modes might act as the bridge transferring from voltage-mode to current-mode and vice versa, respectively. A novel mixed-mode (including voltage, current, transconductance, and transresistance modes) biquad filter with one input and seven outputs or two inputs and eight outputs is presented. The proposed filter structure only uses a single fully differential current conveyor (FDCCII), three resistors and two grounded capacitors, which are the least components necessary for realizing voltage, current, transresistance modes all five standard filter functions and transconductance-mode band-pass, high-pass filter functions from eight output terminals. Moreover, the new mixed-mode biquad filter still enjoys (i) the employment of two grounded capacitors (attractive for absorbing shunt parasitic capacitance and ideal for IC implementation), (ii) orthogonal control of ω₀ and Q (easy for tunability), and (iii) high output impedance of three current outputs (good for cascadability). H-Spice simulation results verify the theoretical analysis.     

Electronically Tunable Single-Input Five-Output Voltage-Mode Universal Filter Using VDTAs and Grounded Passive Elements

This paper presents a possible usage of the voltage differencing transconductance amplifier (VDTA) for the design of an electronically tunable single-input five-output voltage-mode universal filter. The presented filter is constructed using two VDTAs, two capacitors and two resistors that are all grounded. The circuit simultaneously realizes lowpass (LP), bandpass (BP), highpass (HP), bandstop (BS) and allpass (AP) filtering responses, without changing the circuit topology. The circuit is capable of providing an independent electronic control of the natural angular frequency (ω ₀) and the quality factor (Q) through the transconductance gains of the VDTAs. By simply adjusting the transconductance ratio, a high-Q filter can also be obtained. Because of the high-input impedance of the circuit, it is advantageous for cascade connection. To support the theoretical analysis, the properties of the designed filter have been verified by PSPICE simulation results.     

High-Input and Low-Output Impedance Voltage-Mode Universal Biquadratic Filter Using DDCCs

A new three inputs and single output voltage-mode universal biquadratic filter with high-input and low-output impedance using three plus-type differential difference current conveyors, two grounded capacitors and two grounded resistors is presented. The proposed circuit offers the following features: realization of all the standard filter functions, that is, high-pass, bandpass, low-pass, notch, and all-pass filters, no requirements for component matching conditions, the use of only grounded capacitors and resistors, high-input and low-output impedance and low active and passive sensitivities.     

Versatile current-mode universal biquadratic filter using DO-CCIIs

In this article, a new three-input and three-output versatile current-mode universal biquadratic filter is proposed. The circuit employs three dual-output current conveyors (DO-CCIIs) as active elements together with three grounded resistors and two grounded capacitors. The proposed configuration exhibits low-input impedance and high-output impedance which is important for easy cascading in the current-mode operations. It can be used as either a single-input and three-output or three-input and two-output circuit. In the operation of single-input and three-output circuit, the lowpass, bandpass and bandreject can be realised simultaneously, while the highpass filtering response can be easily obtained by connecting appropriated output current directly without using addition stages. In the operation of three-input and two-output circuit, all five generic filtering functions can be easily realised by selecting different three input current signals. The filter permits orthogonal controllability of the quality factor and resonance angular frequency, and no component matching conditions or inverting-type input current signals are imposed. 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.     

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.