Study of Adjustable Gains for Control of Oscillation Frequency and Oscillation Condition in 3R-2C Oscillator

An idea of adjustable gain in order to obtain controllable features is very useful for design of tuneable oscillators. Several active elements with adjustable properties (current and voltage gain) are discussed in this paper. Three modified oscillator conceptions that are quite simple, directly electronically adjustable, providing independent control of oscillation condition and frequency were designed. Positive and negative aspects of presented method of control are discussed. Expected assumptions of adjustability are verified experimentally on one of the presented solution

Minimum Component Based Sinusoidal Oscillator Using Single OTRA

In this paper a new Operational transresistance amplifier (OTRA) based sinusoidal oscillator is proposed. It uses two resistors, two capacitors and a single OTRA. Sensitivity analysis and non-ideality analysis behavior of OTRA on oscillator operation is also investigated. The proposed oscillator circuit is designed using PSPICE simulation and 0.18µm AGILENT CMOS process parameters. PSPICE simulation results agree well with the theoretical analysis of the proposed circuit

Deriving (MO)(I)CCCII Based Second-order Sinusoidal Oscillators with Non-interactive Tuning Laws using State Variable Method

The paper discusses systematic realization of second-order sinusoidal oscillators using multiple-output second-generation current controlled conveyor (MO-CCCII) and/or its inverting equivalent, namely the multiple-output inverting second-generation current controlled conveyor (MO-ICCCII) by state variable method. State variable method is a powerful technique and has been used extensively in the past to realize active RC oscillators using a variety of active building blocks (ABB). In this work, a noninteractive relationship between the condition of oscillation (CO) and the frequency of oscillation (FO) has been chosen priori and then state variable method is applied to derive the oscillators with grounded capacitors. All the resulting oscillator circuits, eight of them, are “resistor-less”, employ grounded capacitors and do not use more than three (MO)(I)CCCIIs. PSPICE simulation results of a possible CMOS implementation of the oscillators using 0:35μm TSMC CMOS technology parameters have validated their workability

Design of RC sinusoidal oscillator based on active building blocks

Bakalárska práca je venovaná RC oscilátorom s použitím funkčných blokov a operačných zosilovačov. Na počiatku je urobený rešerš literatúry zaoberajúcej sa konštrukciou a návrhom RC oscilátorov, a použitiu rôznych funkčných blokov pri tomto návrhu. Jednotlivé funkčné bloky sú diskutované a sú vybrané rôzne zapojenia s použitím týchto blokov, ktoré sú simulované analýzou na počítači pomocou PSpice a SNAP. Je overený vznik oscilácií a vplyv jednotlivých súčiastok v zapojení. V druhej časti sú realizované vybrané zapojenia a overené teoretické poznatky na praktickej realizácii. Údaje získané z počítačovej simulácie a praktickej realizácie sú potom porovnané, a taktiež jednotlivé zapojenia sú porovnané medzi sebou.Thesis is focused on RC oscillators employing active building blocks and operational amplifiers. In the beginning, review of available literature talking about this topic is done. Different building blocks and circuits containing those blocks are picked and some of them simulated with PSpice and SNAP programs. Oscillation creation and influence of circuit components is verified. Those circuits are realized in practical application and simulation results are compared to those gained from real world circuits, also the chosen circuits are compared between each other.

Realization of electronically tunable voltage-mode/current-mode quadrature sinusoidal oscillator using ZC-CG-CDBA

a b s t r a c t This paper presents a first of its kind canonic realization of active RC (ARC) sinusoidal oscillator with non-interactive/independent tuning laws, which simultaneously provides buffered quadrature voltage outputs and explicit quadrature current outputs. The proposed circuit is created using a new active building block, namely the Z-copy controlled-gain current differencing buffered amplifier (ZC-CG-CDBA). The circuit uses three resistors and two grounded capacitors, and provides independent/non-interactive control of the condition of oscillation (CO) and the frequency of oscillation (FO) by means of different resistors. Other advantageous features of the circuit are the inherent electronic tunability of the FO via controlling current gains of the active elements and the suitability to be employed as a low-frequency oscillator. A non-ideal analysis of the circuit is carried out and experimental results verifying the workability of the proposed circuit are included

Development of reliability methodology for systems engineering. Volume II - Application - Design reliability analysis of a 250 volt-ampere static inverter Final report

Design stage reliability analysis application to static inverte

Study of Electronic Control and Real Behavior in Variable Filtering and Oscillating Applications of Modern Active Elements

Práce pojednává o elektronicky nastavitelných a konfigurovatelných aplikacích moderních aktivních prvků. Velmi často jsou prezentovány rozmanité aktivní prvky v aplikacích filtrů a oscilátorů, které víceméně vychází ze základních a vesměs podobných principů syntézy a návrhu, avšak není provedena detailní studie reálného chování a možností elektronického řízení parametrů. Při precizním návrhu aplikace je však důležité identifikovat problémové vlastnosti a stanovit, jak moc ovlivní funkci zařízení. Je zde srovnáváno několik filtračních struktur založených na běžných i modifikovaných principech integrátorové syntézy z pohledu konfigurovatelnosti, variabilnosti a druhu použitého elektronického řízení. K řízení jsou využívány standardní metody, jako je změna transkonduktance, změna vstupního (intrinzického) odporu proudových svorek a již méně typická možnost řízení pomocí proměnného proudového zesílení. Ta poslední metoda řízení umožnila objevit zcela unikátní filtr s elektronickou změnou přenosu z PZ na FČ, který jednoduchostí překonává běžnější integrátorové struktury, kde je zapotřebí fyzické přepojení v obvodu. Větší část práce je věnována elektronicky řiditelným oscilátorům, a to hlavně kvadraturním. Je prezentováno několik velice jednoduchých typů, které vyžadují nejmenší množství aktivních i pasivních prvků, i složitějších koncepcí, které již vyžadují více aktivních prvků, ale odstraňují některé nevýhody jednoduchých variant. Především je i zde kladen důraz na studium reálného chování, které objasňuje různé problémy se vzájemnou závislostí oscilační podmínky a oscilačního kmitočtu, závislostí amplitudy kvadraturních oscilátorů na ladícím parametru, vlivu změny ladícího parametru na plnění oscilačních podmínek, atd. V rámci této části byl definován nový typ či modifikace aktivního prvku tzv. current-gain-controlled current conveyor transconductance amplifier (CGCCCTA). Požadavek na nové aplikace zejména v oblastí oscilátorů pro Ústavem telekomunikací nově vyvíjený proudový zesilovač a digitálně řízený proudový zesilovač nechal vzniknout několika kapitolám práce, kde může být tento prvek výhodně použit. Podstatný přínos, který je důležitý především pro praxi, spočívá v testování většiny navržených obvodů experimentálně a stanovení přesných návrhových vztahů, které zohledňují reálné chování obvodu a potvrzují experimenty získané výsledky.The thesis deals with electronically adjustable and configurable applications of the modern active elements. In the field there were presented various active elements in applications of the analog filters and oscillators which stem from basic and more or less similar principles of circuit synthesis and design. However, there is not provided study of real behavior in detail and in most cases electronic control of the various parameters in application is not verified. In the precise design of application is very important to identify problematic features and determine how much it influences functionality of the device. In this work several filtering structures based on common and modified synthesis principles (integrator loops) are compared in the view of multifunctionality, configurability, variability, kind of used electronic control and impact of influences of real elements on behavior. There are used standard methods like adjusting of variable transconductance, intrinsic value of current input resistance and not so common method based on variable current gain in design of modified and improved multifunctional filtering circuits. The last method of mentioned control enabled to find quite unique filter which allows continuous electronic change of transfer from band-reject to all-pass filter of the 2nd order without reconnection. It is much simpler than previous and more common integrator loops. Larger part of this work is focused on electronically controllable oscillators mainly on quadrature types. There is presented several very simply and elementary realizations which require minimal number of active and passive elements. There are also slightly or more complicated solutions which remove some drawbacks of mentioned simpler variants. First of all there is given attention on study of real behavior which make obvious different problems with mutual dependence of oscillation condition and oscillation frequency, dependence of produced amplitudes (quadrature types) on parameter which is controlling oscillation frequency, influence of this parameter on oscillation condition, etc. In the framework of this part of the thesis there was introduced a novel modification of current conveyor transconductance amplifier (CCTA) so called current-gain-controlled current conveyor transconductance amplifier (CGCCCTA). Requirements for novel applications in the field of oscillators for newly developed controllable current amplifier and digitally controllable current amplifier (DACA) at the Department of Telecommunication FEEC BUT lead to creation of several chapters of this work where mentioned active elements can be used. The important contribution of this work (for practical approach) is also experimental testing of most of designed circuits and determination of exact design equations and rules which take into account real behavior of circuits and confirm results obtained from experiments.

Investigating Student Learning of Analog Electronics

Instruction in analog electronics is an integral component of many physics and engineering programs, and is typically covered in courses beyond the first year. While extensive research has been conducted on student understanding of introductory electric circuits, to date there has been relatively little research on student learning of analog electronics in either physics or engineering courses. Given the significant overlap in content of courses offered in both disciplines, this study seeks to strengthen the research base on the learning and teaching of electric circuits and analog electronics via a single, coherent investigation spanning both physics and engineering courses. This dissertation has three distinct components, each of which serves to clarify ways in which students think about and analyze electronic circuits. The first component is a broad investigation of student learning of specific classes of analog circuits (e.g., loaded voltage dividers, diode circuits, and operational amplifier circuits) across courses in both physics and engineering. The second component of this dissertation is an in-depth study of student understanding of bipolar junction transistors and transistor circuits, which employed the systematic, research-based development of a suite of research tasks to pinpoint the specific aspects of transistor circuit behavior that students struggle with the most after instruction. The third component of this dissertation focuses more on the experimental components of electronics instruction by examining in detail the practical laboratory skill of troubleshooting. Due to the systematic, cross-disciplinary nature of the research documented in this dissertation, this work will strengthen the research base on the learning and teaching of electronics and will contribute to improvements in electronics instruction in both physics and engineering departments. In general, students did not appear to have developed a coherent, functional understanding of many key circuits after all instruction. Students also seemed to struggle with the application of foundational circuits concepts in new contexts, which is consistent with existing research on other topics. However, students did frequently use individual elements of productive reasoning when thinking about electric circuits. Recommendations, both general and specific, for future research and for electronics instruction are discussed

Linearizing techniques for voltage controlled oscillator based analog to digital converters

Voltage controlled oscillator (VCO) based ADC is an important class of time-domain ADC that has gained widespread acceptance due to their several desirable properties. VCO-based ADCs behave like an open-loop continuous time ΔΣ modulator and achieve excellent resolution by first order noise shaping the quantization error. However, the SNDR of an open-loop VCO-based ADC is severely distortion limited by the voltage-to-frequency tuning characteristics of the VCO. This work examines various techniques that have already been proposed to overcome the VCO tuning non-linearity problem. Two new VCO-based ADC architectures, that overcome the limitations of the conventional approaches, are proposed. In the first approach, the ADC is linearized by forcing the VCO to operate at only two operating points using a front-end two level modulator. With this technique, the linearity is improved without using either a multi-bit feedback DAC or calibration. Fabricated in a 90 nm CMOS process, the prototype ADC achieves better than 71 dB SFDR and 59.1 dB SNDR in 8 MHz signal bandwidth while consuming 4.3 mW power. The ADC achieves a figure of merit of 366 fJ/conv-step, which is comparable with other state of the art time based ADCs. In the second approach, the need for a front-end two level modulator is obviated using linearizers, which introduce an inverse of VCO’s voltage to frequency characteristics in the signal path. A deterministic digital calibration unit runs continuously in the background and builds the inverse voltage to frequency transfer function. Implemented in a 90nm CMOS process, this on-chip calibration improves SFDR of the prototype ADC from 46 dB to more than 83 dB. The ADC consumes 4.1 mW power and achieves 73.9 dB SNDR in 5 MHz signal bandwidth resulting in an excellent figure of merit of 101 fJ/conv-step