Novel active function blocks and their applications in frequency filters and quadrature oscillators

Kmitočtové filtry a sinusoidní oscilátory jsou lineární elektronické obvody, které jsou používány v široké oblasti elektroniky a jsou základními stavebními bloky v analogovém zpracování signálu. V poslední dekádě pro tento účel bylo prezentováno velké množství stavebních funkčních bloků. V letech 2000 a 2006 na Ústavu telekomunikací, VUT v Brně byly definovány univerzální proudový konvejor (UCC) a univerzální napět'ový konvejor (UVC) a vyrobeny ve spolupráci s firmou AMI Semiconductor Czech, Ltd. Ovšem, stále existuje požadavek na vývoj nových aktivních prvků, které nabízejí nové výhody. Hlavní přínos práce proto spočívá v definici dalších původních aktivních stavebních bloků jako jsou differential-input buffered and transconductance amplifier (DBTA), current follower transconductance amplifier (CFTA), z-copy current-controlled current inverting transconductance amplifier (ZC-CCCITA), generalized current follower differential input transconductance amplifier (GCFDITA), voltage gain-controlled modified current-feedback operational amplifier (VGC-MCFOA), a minus-type current-controlled third-generation voltage conveyor (CC-VCIII-). Pomocí navržených aktivních stavebních bloků byly prezentovány původní zapojení fázovacích článků prvního řádu, univerzální filtry druhého řádu, ekvivalenty obvodu typu KHN, inverzní filtry, aktivní simulátory uzemněného induktoru a kvadraturní sinusoidní oscilátory pracující v proudovém, napět'ovém a smíšeném módu. Chování navržených obvodů byla ověřena simulací v prostředí SPICE a ve vybraných případech experimentálním měřením.Frequency filters and sinusoidal oscillators are linear electric circuits that are used in wide area of electronics and also are the basic building blocks in analogue signal processing. In the last decade, huge number of active building blocks (ABBs) were presented for this purpose. In 2000 and 2006, the universal current conveyor (UCC) and the universal voltage conveyor (UVC), respectively, were designed at the Department of Telecommunication, BUT, Brno, and produced in cooperation with AMI Semiconductor Czech, Ltd. There is still the need to develop new active elements that offer new advantages. The main contribution of this thesis is, therefore, the definition of other novel ABBs such as the differential-input buffered and transconductance amplifier (DBTA), the current follower transconductance amplifier (CFTA), the z-copy current-controlled current inverting transconductance amplifier (ZC-CCCITA), the generalized current follower differential input transconductance amplifier (GCFDITA), the voltage gain-controlled modified current-feedback operational amplifier (VGC-MCFOA), and the minus-type current-controlled third-generation voltage conveyor (CC-VCIII-). Using the proposed ABBs, novel structures of first-order all-pass filters, second-order universal filters, KHN-equivalent circuits, inverse filters, active grounded inductance simulators, and quadrature sinusoidal oscillators working in the current-, voltage-, or mixed-mode are presented. The behavior of the proposed circuits has been verified by SPICE simulations and in selected cases also by experimental measurements.

Balanced-Output CCCFOA and Its Utilization in Grounded Inductance Simulator with Various Orders

In this paper, a new realization of current-controlled current feedback operational amplifier with balanced voltage outputs (BO-CCCFOA) is presented. A resistorless grounded lossless positive inductance simulator (PIS) using two BO-CCCFOAs and a grounded capacitor is reported. The resulting equivalent inductance value of PIS can be adjusted either via change of input intrinsic resistance of BO-CCCFOAs by means of biasing currents or by order of fractional-order capacitor (FoC). FoCs of order = (0.25; 0.5; 0.75; 1) were emulated via 5th-order Foster II RC network and values optimized using modified least squares quadratic (MLSQ) method. In frequency range 30 kHz - 30 MHz the obtained phase angle deviation of FoCs and mean values of corresponding relative phase error are below ±1 degree and ±4.3%, respectively. Considering the bandwidth for phase angle deviation less than 3 degree, the proposed fractional-order PIS operates over two decades. The behavior of the PIS circuit with various orders was tested via implementation in RLC ladder prototype of voltage-mode high-pass filter. Theoretical results are verified by SPICE simulations using TSMC 0.18 m level-7 LO EPI SCN018 CMOS process parameters with ±1 V supply voltages.In this paper, a new realization of current-controlled current feedback operational amplifier with balanced voltage outputs (BO-CCCFOA) is presented. A resistorless grounded lossless positive inductance simulator (PIS) using two BO-CCCFOAs and a grounded capacitor is reported. The resulting equivalent inductance value of PIS can be adjusted either via change of input intrinsic resistance of BO-CCCFOAs by means of biasing currents or by order of fractional-order capacitor (FoC). FoCs of order = (0.25; 0.5; 0.75; 1) were emulated via 5th-order Foster II RC network and values optimized using modified least squares quadratic (MLSQ) method. In frequency range 30 kHz - 30 MHz the obtained phase angle deviation of FoCs and mean values of corresponding relative phase error are below ±1 degree and ±4.3%, respectively. Considering the bandwidth for phase angle deviation less than 3 degree, the proposed fractional-order PIS operates over two decades. The behavior of the PIS circuit with various orders was tested via implementation in RLC ladder prototype of voltage-mode high-pass filter. Theoretical results are verified by SPICE simulations using TSMC 0.18 m level-7 LO EPI SCN018 CMOS process parameters with ±1 V supply voltages

Universal Voltage Conveyor and its Novel Dual-Output Fully-Cascadable VM APF Application

This letter presents a novel realization of a voltage-mode (VM) first-order all-pass filter (APF) with attractive features. The proposed circuit employs a single readily available six-terminal active device called as universal voltage conveyor (UVC) and only grounded passive components, which predict its easy monolithic integration with desired circuit simplicity. The auxiliary voltage input (W) and output (ZP, ZN) terminals of the device fully ensure easy cascadability of VM APF, since the input and output terminal impedances are theoretically infinitely high and zero, respectively. Moreover, thanks to mutually inverse outputs of the UVC, the proposed filter simultaneously provides both inverting and non-inverting outputs from the same configuration. All of these features make the UVC a unique active device currently available in the literature. The behavior of the filter was experimentally measured using the readily available UVC-N1C 0520 chip, which was produced in cooperation with ON Semiconductor Czech Republic, Ltd.This letter presents a novel realization of a voltage-mode (VM) first-order all-pass filter (APF) with attractive features. The proposed circuit employs a single readily available six-terminal active device called as universal voltage conveyor (UVC) and only grounded passive components, which predict its easy monolithic integration with desired circuit simplicity. The auxiliary voltage input (W) and output (ZP, ZN) terminals of the device fully ensure easy cascadability of VM APF, since the input and output terminal impedances are theoretically infinitely high and zero, respectively. Moreover, thanks to mutually inverse outputs of the UVC, the proposed filter simultaneously provides both inverting and non-inverting outputs from the same configuration. All of these features make the UVC a unique active device currently available in the literature. The behavior of the filter was experimentally measured using the readily available UVC-N1C 0520 chip, which was produced in cooperation with ON Semiconductor Czech Republic, Ltd

Further Generalization and Approximation of Fractional-Order Filters and Their Inverse Functions of the Second-Order Limiting Form

This paper proposes a further generalization of the fractional-order filters whose limiting form is that of the second-order filter. This new filter class can also be regarded as a superset of the recently reported power-law filters. An optimal approach incorporating constraints that restricts the real part of the roots of the numerator and denominator polynomials of the proposed rational approximant to negative values is formulated. Consequently, stable inverse filter characteristics can also be achieved using the suggested method. Accuracy of the proposed low-pass, high-pass, band-pass, and band-stop filters for various combinations of design parameters is evaluated using the absolute relative magnitude/phase error metrics. Current feedback operational amplifier-based circuit simulations validate the efficacy of the four types of designed filters and their inverse functions. Experimental results for the frequency and time-domain performances of the proposed fractional-order band-pass filter and its inverse counterpart are also presented

On the Design of Power Law Filters and Their Inverse Counterparts

This paper presents the optimal modeling of Power Law Filters (PLFs) with the low-pass (LP), high-pass (HP), band-pass (BP), and band-stop (BS) responses by means of rational approximants. The optimization is performed for three different objective functions and second-order filter mother functions. The formulated design constraints help avoid placement of the zeros and poles on the right-half s-plane, thus, yielding stable PLF and inverse PLF (IPLF) models. The performances of the approximants exhibiting the fractional-step magnitude and phase responses are evaluated using various statistical indices. At the cost of higher computational complexity, the proposed approach achieved improved accuracy with guaranteed stability when compared to the published literature. The four types of optimal PLFs and IPLFs with an exponent alpha of 0.5 are implemented using the follow-the-leader feedback topology employing AD844AN current feedback operational amplifiers. The experimental results demonstrate that the Total Harmonic Distortion achieved for all the practical PLF and IPLF circuits was equal or lower than 0.21%, whereas the Spurious-Free Dynamic Range also exceeded 57.23 and 54.72 dBc, respectively

Universal Pseudo-Differential Filter Using DDCC and DVCCs

In the paper, a universal preudo-differential second-order filter operating in voltage mode, where both input and output are differential, is presented. The circuit is formed by one differential difference current conveyor (DDCC), two differential voltage current conveyors (DVCCs), and five passive elements. The filter is characterized by high input impedance, minimum number of passive elements that are all grounded, and high common-mode rejection ratio (CMRR). The proposed filter structure is able to realize all five standard frequency filter responses. Non-ideal analysis has been performed by considering the real parasitic parameters of the active elements. The optimization of passive element values has been done in terms of minimal shift of the pole-frequency and to obtain the maximum stop-band attenuation of the high-pass filter response. Functionality is verified by simulations and experimental measurements using readily available integrated circuit UCC-N1B 0520

Grounded Voltage Controlled Positive Resistor with Ultra Low Power Consumption

In this work, a new CMOS based grounded voltage controlled positive resistor (GVCPR) with one control voltage is proposed. The proposed GVCPR employs only five CMOS transistors, one operated in triode region and others operated in saturation region or OFF. One of the main properties of the proposed GVCPR is its ultra low power consumption; however, a single active component matching condition is needed. A number of SPICE simulation results using IBM 0.13 um SIGE013 level-7 CMOS process parameters such as its performance analysis and verification in tunable voltage-mode first-order all-pass filter and high-Q & high-gain voltage-mode multiple-feedback second-order band-pass filter are included to confirm the theory. The superior performance of the proposed GVCPR is also proven by numeric Figure of Merit calculation