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New Current-mode Multiphase Sinusoidal Oscillators Based on CCCCTA-based Lossy Integrators

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An implementation of current-mode multiphase sinusoidal oscillators is presented. Using CCCCTA-based lossy integrators, odd and odd/even phase systems can be realised with following advantages. The condition of oscillation and frequency of oscillation can be electronically/orthogonally tuned. The high output impedances facilitate easy driving an external load without additional current buffers. The proposed MSOs provide odd or even phase signals that are equally spaced in phase and equal amplitude. The circuit requires one CCCCTA and one grounded capacitor per phase without external resistor and additional current amplifier. The effects of the non-idealities of the CCCCTA-lossy integrator sections were also studied. The results of PSPICE simulations using BJT CCCCTA are included to verify theory. Streszczenie. Zaprezentowano wielofazowy generator w trybie prądowym. Stosując integrator CCCCTA uzyskuje się przesunięcie fazowe parzyste lub nieparzyste. Układ charakteryzuje się dużą impedancją wyjściową. Zbada no wpływ nieidealnych parametrów integratora. (Nowy wielofazowy generator sinusoidalny o trybie prądowym wykorzystujący integrator typu CCCCTA) Keywords: multiphase sinusoidal oscillator; current-mode; CCCCTA. Słowa kluczowe: genersator sinusoidalny, tryb prądowy, CCCCTA. Introduction It is well known that multiphase sinusoidal oscillator (MSO) is an important blocks for various applications. For example, in telecommunications it is used for phase modulators, quadrature mixers [1], and single-sideband generators [2]. In measurement systems, MSO is employed for vector generators or selective voltmeters [3]. It can also be utilized in power electronic systems [4]. Recently, current-mode circuits have been receiving considerable attention of due to their potential advantages such as inherently wide bandwidth, lower slew-rate, greater linearity, wider dynamic range, simple circuitry and low power consumption [5]. The interesting active[...]

New Current-mode Quadrature Sinusoidal Oscillator Using Single DVCCTA as Active Element DOI:10.15199/48.2016.09.56

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This paper presents the design of a current-mode quadrature sinusoidal oscillator. It can generate two current-mode sinusoidal outputs with 90 degree phase difference called as quadrature signal. The proposed sinusoidal oscillator employs single differential voltage current conveyer transconductance amplifier (DVCCTA), two grounded capacitors and three resistors. The tuning of frequency of oscillation (FO) and condition of oscillation (CO) can be done independently. Also the frequency of oscillation can be electronically tuned which is suitable for modern control system using microcontroller or microprocessor. The impedance at output node is high impedance which can directly drive an external load or connect to another circuit without the use of current buffers. A number of simulation results based on PSPICE program using 0.25 μm TSMC CMOS parameters are included to exhibit performance, workability and effectiveness of the proposed sinusoidal oscillator. Streszczenie. W artykule opisano projekt prądowego generatora sinusoidalnego. Może on generować sygnały z przesunięciem 90. Generator wykorzystuje różnicowy przetwornik napięcie prąd ze wzmacniaczem transkonduktancyjnym - DVCCTA., dwa uziemione kondensatory I trzy rezystory. Generator może być strojony elektronicznie. Nowy generator sinusoidalny wykorzystujący jako aktywny element układ DVCCTA. Keywords: qudrature sinusoidal oscillator; current-mode; DVCCTA. Słowa kluczowe: generator sinusoidalny, układ DVCCTA. Introduction In electrical and electronic engineering, the sinusoidal signal has gained much of importance. The circuit which generates the sine wave is called as oscillator. Ideally, the oscillator should generate the sinusoidal signal with low total harmonic distortions (THD). Especially, the quadrature sinusoidal oscillator which provides two sinusoidal signals with 90 degree phase difference is very useful in many applications, for example, in measurement[...]

Single VDCC-Based Electronically Tunable Voltage-Mode Second Order Universal Filter DOI:10.15199/48.2018.04.06

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It is well-known fact that analog filter are important building blocks for signal processing that have variety of applications in fields of communication, sound system, instrumentation, control system etc [1]. A biquad filter which provides several filter responses in the same circuit topology is well-known as universal or multifunction filter. [2- 3]. The number of input and output of the universal filter is used to classify the sort of universal filter. There are singleinput multiple-output (SIMO), multiple-input multiple-output (MIMO) and multiple-input single-output (MISO) filter. The MISO filter is one of the universal filter which has been attracted significant research attention [4]. Most of MISO universal filters use digital method to select the output filter response. So, the way to selection of the output filer response should be done without comment matching condition. The design of electronic circuit in analog signal processing has gone in the use of active building block [5- 9]. Especially, the electronically tunable active building blocks have attracted significant research attention since analog circuits using electronically tunable active building block give more fine-tuning than adjusting the value of passive device. The voltage differencing current conveyors (VDCC) [10] is a recently reported versatile active building block used in the realization of analog signal processing circuits. A very significant advantage of using VDCCs in analog circuit design is that it is able electronic controllability. Literature review shows that, a number of the analog circuits using VDCC as active element have been found for examples, inductance simulator [10-11], capacitance multiplier [12-13], versatile passive element simulator [14- 15], square and triangular wave generator [16], sinusoidal oscillator [6, 13, 17-20], first order allpass filter [21], ladder filter [22] etc. The VDCC based universal filters have been pro[...]

Voltage-Mode First-Order Allpass Filter with Grounded Capacitor and Electronic Controllability DOI:10.15199/48.2019.03.24

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The first-order allpass filter or well-known as phase shifter circuit is utilized to delay the sinusoidal output phase from the sinusoidal input phase with equal magnitude of the output signal for all operational frequency. For the first order allpass system, the phase of output waveform can be shifted from - 180 to 0 or from 0 to 180. It is also called as the phase shifter circuit. This filter is important in many analog signal processing systems for examples communication system, measurement and instrument system, biomedical system etc. [1] There has been continuous increase in the design of electronic circuit using the active building block [2-8]. The well-known active building blocks are OPAMP, OTA and CCII. These active elements offer the flexibility and convenience to design the circuit by using minimum component count. The voltage differencing current conveyor (VDCC) [9] is interesting active element. It is electronically controllable active building block, where its transconductance gain (gm) can be adjusted via DC bias current. The VDCC based circuits have been introduced in the open literature. These circuits include sinusoidal waveform generator [10-13], capacitance multiplier [14], second order multifunction filter [15-18], inductance simulator [9, 19-20], ladder filter [21] and first order filter [22-23]. The first-order voltage-mode filter using z-copy controlled gain voltage differencing current conveyor (ZC-CGVDCC) is presented in [22]. The circuit comprises single ZC-CGVDCC and single grounded capacitor. The phase variation is electronically adjusted. However, this first-order filter requires the active building block with multiple output current terminals. Also, the internal construction of ZCCGVDCC looks complicated. Various first-order allpass filters using z-copy voltage differencing current conveyor (ZC-VDCC) are proposed in [23]. These circuits contain current-mode, m[...]

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