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Design of measuring solutions for circuits with differential signals
Jemelík, Lukáš ; Hanák, Pavel (referee) ; Jeřábek, Jan (advisor)
This master´s thesis deals about a measuring structures of elements working at a current mode. There were outlined structures for measuring input and output impedance. These structures were simulated for DACA element. It deals with a voltage to current and current to voltage converters. All structures and converters were simulated at computer program PSpice. Selected variant were practically verified and control measuring was realized.
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Analysis of differential and non-differential filtering structures with adjustable current amplifier
Dvořák, Jan ; Vrba, Kamil (referee) ; Jeřábek, Jan (advisor)
The master thesis deals with designs of the single-ended and the fully-differential secondorder frequency filters with adjustable parameters. This filters operate in the current mode where main element is the current amplifier DACA (Digitally Adjustable Current Amplifier). The first part describes basic behaviour of frequency filters and distribution according to filter funcion, used parts and structure. The second part of thesis describes the design of the frequency filters by the M-C signal-flow graphs and the transformating single-ended structures to the fully-differential forms. The next part deals with properties of the active elements and their simulation models. The following part describe six circuits of the frequency filters with adjustable parameters and their simulations. Four simulation models with different properties were used for simulating of the DACA in the each circuits. The last part deals with the practical design and measurement of the selected frequency filters.
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Fully-differential frequency filter designing with current active elements using signal-flow graphs method
Štork, Petr ; Jeřábek, Jan (referee) ; Langhammer, Lukáš (advisor)
This master’s thesis deals with designing of fully-differential current-mode frequency filters using signal-flow graphs method. The first part is focused on a general description of frequency filters, its function and division. Active elements that create these frequency filters, such as multi-output current follower (MO-CF), balanced or multi-output transconductance amplifier (BOTA, MOTA) and digitally adjustace current amplifier (DACA) are described in the following part. Next, problems and various techniques of designing such filters are discussed on a theoretic basis. In the remaining part of the thesis there are six circuits of frequency filters described in detail; these connections are then transferred of passive elements to a proposed connections, with the assistance of a so-called reflection. Calculations of passive form are stated, as well as results of simulations, where nondifferential and differential variations of these designed frequency filters are compared. Finaly, it has been selected some variants of designs, which has been manufactured, then measured out and resulet has been compare between each other.
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Differential frequency filters with modern active elements
Kubík, Milan ; Vrba, Kamil (referee) ; Jeřábek, Jan (advisor)
The master thesis focuses on design of fully-differential frequency filters with modern active components in current mode. First part informs about problems concerning analogue frequency filters and creating differential structures. Second part deals with methods of create filters and used active components - DACA (Digital Adjustable Current Amplifier) and MO-CF (Multiple Output Current Follower). Own design of differential filters is divided on two parts. In the first part of design results there are filters created with synthetic higher-order elements. There are presented circuit structures implementing the third order low pass filter and high pass filter. In the second part are designed filters with signal flow graphs. The first circuit implementing low pass, high pass, band pass, band rejection and all-pass filter. The second circuit is with help of the same set of current amplification by DACA components tuning of the natural frequency. For this circuit was make sensitivity analysis. In the final part is practical implementation of the differential frequency filter for tuning of the natural frequency and summarises the thesis.
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Application possibilities of LNVGA programmable amplifier
Sobotka, Josef ; Hanák, Pavel (referee) ; Jeřábek, Jan (advisor)
This thesis deals with the theoretical description of the qualitative characteristics and parameters of some modern active elements, also discusses the theory of signal flow graphs at the level applicable for the following frequency filter design methods. The thesis is also generally discussed the issue with the circuit simulator PSpice modeling theory and voltage amplifiers on the basic 6-levels. The practical part of the work is divided into two parts. The first practical part is dedicated to design four levels of simulation model of components LNVGA element. The second practical part contains detailed theoretical proposals for three circuit structures implementing the frequency filters 2nd order (based on the basic structure of the OTA-C) using signal flow graphs with configuration options of Q and fm based on the parameters of active elements in the peripheral structure and their verification with prepared LNVGA model layers.
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Analysis of methods of measurement of fully-differential frequency filters
Kučera, Tomáš ; Kubánek, David (referee) ; Jeřábek, Jan (advisor)
This bachelor thesis focuses on measurements methods of differential frequency -selection filters with active elements in current mode. Firstly it describes differential frequency-selection filters in current mode and conversions from voltage to current mode. Next the thesis deals with measuring of particular voltage converters to differential current and back from differential current to voltage, which is an integral part for measurements of differential frequency-selection filters in current mode. For design of particular converters there was used program OrCAD there and subsequent simulation was executed in program PSpice.
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Electronically controllable frequency filters with current active elements
Suchánek, Tomáš ; Lattenberg, Ivo (referee) ; Kubánek, David (advisor)
The aim of the thesis is to study the possibilities of the electronic frequency ?lter com- posed of active elements operating in current mode. The main opportunities lie in the change control parameters, most are marginal or quality factor frequency. As the active elements are considered especially CC (Current Convejor), controllable current ampli?er DACA (Digitally Adjustable Current Ampli?er) or combination with the current tracker MO-CF (Multiple Output Current Follower). Another part will focus on the management of the above parameters using digital potentiometers and choosing the appropriate ?lter structure. The ?nal task was to digital control parameters using a PC and measuring its properties.
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Analysis of filter structures with controllable amplifiers
Pánek, David ; Langhammer, Lukáš (referee) ; Polák, Josef (advisor)
This bachelor thesis is focused on simulations and practical realizations of already existing frequency filters with modern active components in current mode. New simulation ABM model (Analog Behavioral Model) of DACA (Digital Adjustable Current Amplifier) element was used in the simulations. The first part informs about problems concerning analogue frequency filters. The second part deals with used active components - DACA (Digital Adjustable Current Amplifier), MO-CF (Multiple Output Current Follower), BOTA (Balanced transconductance amplifier) and UCC (universal current conveyor). Four circuits have been chosen and implemented into PCB (printed circuit board) on the basis of simulation results. The first circuit tunes the quality factor with help of DACA component. The second circuit tunes the natural frequency and quality factor with help of DACA components. The third and the fourth circuits are simulated and implemented in differential and also in single ended forms. These circuits tune the natural frequency with help of the same set of current amplification by DACA components. The last part is summary of simulation’s and practical measurement‘s result of this project.
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Analogue emulators of fractional-order circuits
Kubát, Pavel ; Langhammer, Lukáš (referee) ; Dvořák, Jan (advisor)
Diploma thesis deals with circuits contain fractional-order elements. The first part of this paper deals with this problem, there were also described methods of design fractionalorder elements and types of circuits containing the fractiona-order elements which can be applied in practice. Used active elements for practical part can be found in the second chapter. Design of GIC circuits and implementation of fractional-order element inside the circuit are shown in the last chapture. Parasitic analysis and stability of frequency filter containing fractional-order element had been also described.
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