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Frequency filters with difference current amplifier
Jirounek, Matěj ; Lattenberg, Ivo (referee) ; Vrba, Kamil (advisor)
This master´s thesis deals with the differential filters working in the current mode. It is dealt with the design methodologies of these filters and conversion circuits from voltage to current mode. Own work deals with 4 types of differential participation of structures. In this work there has been used programs SNAP and OrCAD. These programs were used for simulations of filters to proposed proper design. Results from this thesis is showed by graphs.
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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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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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Design and realization of V/I and I/V symmetrical converters
Chrást, Jakub ; Koton, Jaroslav (referee) ; Jeřábek, Jan (advisor)
Master´s thesis deals about design of symmetrical converters voltage on current and current on voltage. These converters will be used for measuring frequency characteristics of differential frequency filters. Current feedback amplifier was used as active element. Some circuits useful for this function were chosen. Various integrated circuits were put into these circuits. All variations were simulated in computer program Orcad. In terms of computer simulations the best variation was chosen. Selected variants were practically verified and control measuring were realized.
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Utilization of signal-flow graphs in design of the fully-differential filters
Žůrek, Radomil ; Kubánek, David (referee) ; Jeřábek, Jan (advisor)
The dissertation deals with the design of fully differential frequency filters using the signal flow graphs. It presents the procedures for designing frequency filters, focusing on the active elements such as multiple-output current followers (MO-CF) and digitally adjustable current amplifiers (DACA), which work in a current mode. It is theoretically discussed the issue of designing the M-C graphs, which are the graphic analogy of voltage and current incidence matrices. There are also presented three designs of 2nd order frequency filter circuits using the indirect method of design by M-C graphs and one circuit design using the direct method. The results of each simulation and measurement are presented in a module frequency characteristics. Finally, there is a summary of M-C graphs characteristics and applicability.
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Design of adjustable fully-differential filters with current active elements
Polášek, Lubomír ; Koton, Jaroslav (referee) ; Jeřábek, Jan (advisor)
The master thesis deals with design of the fully differential frequency filters working in the current mode and is focused on possibilities of the natural frequency and the quality factor adjustment. At the beginning, there is a brief description of frequency filters and active elements (MO-CF, FD-CF and DACA), which are used in the thesis. Furthermore, simplified signal flow graphs design method and transformation of passive and active elements to the differential structures are described. The designs of four differential circuitries which provide possibility of tuning the natural frequency or quality factor by the gain of the DACA element are shown in the thesis. Simulation results made in OrCAD program with help of third-order models are included. The practical implementation of the differential frequency filter for tuning of the natural frequency by the DACA elements is shown in the last chapter.
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Design of new active filters, using signal flow graphs
Jašek, František ; Kubánek, David (referee) ; Vrba, Kamil (advisor)
This master’s thesis describes the design of the frequency filters by the help of the graph of the signal flows. There are defined by modern components like GVC (Generalized Voltage Conveyor), GCC (Generalized Current Conveyor), CF (Current Follower), DO-CF (Dual-Output Current Follower), OTA (Operational Transconductance Amplifier), BOTA (Ballanced Operational Transconductance Amplifier) and CFTA (Current Follower Transconductance Amplifier), the graphs of the signal flows, which describe their activity in the thesis. In the other part of the thesis is illustrated the procedure of the design of the frequency filters by the help of the graphs of the signal flows. For the concrete design was selected in the first case as the active component double output current follower and in the second case the CFTA. There are noted all designed circuits of the frequency filters also their characteristic equations in this thesis. The activity of the selected circuits was remitted to the analysis in the simulation program called PSpice. Because the active components, with which was engaged in the design of the filter which doesn’t exist in the real form, that is why the UCC, which is sufficing for attestation of the function of the circuit, was used for the simulation. The simulation was implemented in the frequency range 10 Hz to 10 MHz.
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Current mirror higher-order filters
Novotný, Matouš ; Herencsár, Norbert (referee) ; Lattenberg, Ivo (advisor)
Submitted work engages in suggestion of frequency-selection filters with usage of more active elements of the MCMI (Multi-Output Current Mirror and inverter). The preamble of thesis is applied to theory of frequency-selection filters and possible usage of them. The projected circuit layouts with the active elements are discussed in terms of the impact of parasitic properties of the real models. The part of thesis is numerical suggestion of found solutions, their simulation in suitable program.
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All-pass filters based on modern functional blocks
Horák, Ondřej ; Petržela, Jiří (referee) ; Dostál, Tomáš (advisor)
The present thesis is focused on all pass filters. The principle of all pass filters, their properties, the design of nth degree of these circuits will be analysed in succession and then some of functional blocks, by which these structures can be made, will be described. After that, the allpass filters will be designed and simulated in program OrCAD PSpice. First of all, the analysis will be performed with ideal components, then with real components. After that, the sensitivity and tolerance analysis will be made and the influence of parasite effects on circuit parameters will be examined. Once the experiments are finished, the design of Printed Circuit Board's (PCB) will be realized. Circuit showing the best parameters will be chosen for the design.
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Multifunctional tuned active filter
Šotner, Roman ; Petržela, Jiří (referee) ; Dostál, Tomáš (advisor)
The diploma thesis deals about design of the ARC multifunctional filters using modern functional blocks. These active blocks are for example voltage feedback operational amplifiers (OAs), operational transconductance amplifiers (OTAs), current conveyors (CCIIs) or current mode analog multipliers, current feedback amplifiers (CFAs), integrated circuits with switched capacitors building blocks (SCs) and digital potentiometers. The filters are studied with ideal circuit models and models of third level (3) based on voltage controlled voltage sources, voltage controlled current sources etc. (analog behavioral modelling). The professional macromodels are used for example LT 1364 (Linear Technology), EL 2045 (Intersil), LT 1228 (Linear Technology), LM 13700 (National Semiconductor), EL 2082 (Intersil), AD 844 (Analog Devices) and others. The circuits of the designed filters are simulated in PSpice (OrCAD), parasite effects and effects of the real parts are studied. Tuning and electronic adjusting parameters these filters are discussed and controlled by simulation in PSpice. Properties some simulated circuits are compare with experimental results. In conclusion individual filters are discussed and compared their properties. The constructional details of the some filters are presented at the end of this work.
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