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.     

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 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.     

A 22.5 MHz current-mode KHN-biquad using differential voltage current conveyor and grounded passive elements

In this paper, a current-mode (CM) Kerwin–Huelsman–Newcomb (KHN) biquad is proposed. The circuit employs three differential-voltage current conveyors (DVCCs) as active elements together with two capacitors and four resistors as passive elements, which all are grounded. The circuit simultaneously provides the three basic filter functions, namely bandpass (BP), highpass (HP) and lowpass (LP) functions. The notch and allpass (AP) functions can be obtained by connecting appropriate output currents directly without using additional active elements. The output signals are obtained at high output impedance ports, which is important for easy cascading in CM operation. SPICE simulation results are given to verify the theoretical analyses.     

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.     

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.     

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.     

Current‐Mode Electronically Tunable Universal Filter Using Only Plus‐Type Current Controlled Conveyors and Grounded Capacitors

In this paper we present a new current‐mode electronically tunable universal filter using only plus‐type current controlled conveyors (CCCII+s) and grounded capacitors. The proposed circuit can simultaneously realize lowpass, bandpass, and highpass filter functions—all at high impedance outputs. The realization of a notch response does not require additional active elements. The circuit enjoys an independent current control of parameters ω₀ and ω₀ / Q. No element matching conditions are imposed. Both its active and passive sensitivities are low.     

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.     

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.     

A Versatile Universal Capacitor‐Grounded Voltage‐Mode Filter Using DVCCs

In this paper, a versatile three‐input five‐output universal capacitor‐grounded voltage‐mode filter is proposed. The circuit employs two differential voltage current conveyors as active elements together with two grounded capacitors and four resistors as passive elements. The proposed configuration can be used as either a single‐input five‐output or three‐input two‐output. Unlike the previously reported works, it can simultaneously realize five different generic filtering signals: lowpass, bandpass, highpass, bandreject, and allpass. It still maintains the following advantages: (i) the employment of all grounded capacitors, (ii) no need to employ inverting‐type input signals, (iii) no need to impose component choice, (iv) orthogonal control of the resonance angular frequency ω_o and the quality factor Q, and (v) low active and passive sensitivity performances.     

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.     

A novel mixed-mode current-conveyor-based filter

A new mixed-mode biquad circuit is presented. The circuit uses six single-output plus-type second-generation current-conveyors (CCII+s), a single dual-output CCII+, two grounded capacitors, eight resistors, at least two of them permanently grounded, and can realize lowpass, highpass, bandpass, notch, lowpass notch, highpass notch and allpass responses from the same topology. The circuit can be driven by voltage or current and its output can be voltage or current. The parameters ω₀ and ω₀/Q ₀ enjoy independent electronic tunability. Simulation results are included.     

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.     

A novel mixed-mode OTA-C universal filter

A novel mixed-mode biquad circuit is presented. The circuit uses six single-output- and one dual-output-operational transconductance amplifiers, two grounded capacitors; and can realize lowpass, highpass, bandpass, notch, lowpass-notch, highpass-notch and allpass responses from the same topology. The circuit can be driven by voltage or current and its output can be voltage or current. The parameters ω_o and ω_o/Q _o enjoy independent electronic tunability. Simulation results are included.     

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 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.     

Current-conveyor-based single-element-controlled and current-controlled sinusoidal oscillators

A new single-element-controlled sinusoidal oscillator circuit that incorporates two second generation current conveyors (CCIIs), two grounded capacitors and two resistors is presented and analysed. The circuit is beneficial to monolithic integrated circuit implementation by the use of grounded capacitors. In addition, a new current-controlled sinusoidal oscillator using only two second generation current controlled conveyors (CCCIIs) and two grounded capacitors can be achieved by replacing CCIIs and resistors series at X terminals with CCCIIs. The oscillators provide extremely low passive ω₀-sensitivities and good frequency stability. Moreover, the oscillation frequencies of the CCII-based and the CCCII-based oscillators can be controlled, respectively, by a grounded resistor and by an external bias current. Experimental and SPICE simulation results that confirm the theoretical predictions are given.     

Novel Voltage-Mode All-Pass Filter Based on Using DVCCs

In this paper, a novel design for realizing a voltage-mode (VM) all-pass filter utilizing two differential voltage current conveyors (DVCCs) is proposed. Also, the suggested filter uses a canonical number of passive elements (one grounded capacitor and one resistor) without requiring any element matching condition. The proposed filter has high input and low output impedances, which make it suitable for cascading. The effects of the nonidealities of the DVCCs on the proposed design are investigated. As an application, a quadrature oscillator is designed using the proposed VM all-pass filter and an integrator. The proposed filter and oscillator circuits are simulated using the SPICE simulation program to confirm the theory.