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Design and verification of properties of current mirrors with unipolar transistors
Drápalík, Michal ; Hanák, Pavel (referee) ; Vrba, Kamil (advisor)
The work named Design and verification of properties of current mirrors with unipolar transistors solves the problems of simplify the calculation of current transmission. During the calculation we neglet unimportant parametres. In the begining is theory of current mirrors. For every of each selected mirrors there is calculation of SNAP programme. Following step is simplify calculation by math operations. Using simplified models of replacement transistors we can make easy calculation of current transmission. In the end of work there are all results of calculation.
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Frequency filters with untraditional combination of active elements
Filgas, Jaroslav ; Herencsár, Norbert (referee) ; Jeřábek, Jan (advisor)
The Bachelor’s thesis deals with the theory and designing of analog frequency filters of the second order, which operate in current mode and use the untraditional combination of active elements. The filters are designed by means of the autonomous circuits. Active elements used in the design is Multiple Output Current Follower MO-CF, Digitally Controlled Current Amplifier DACA, Generalized Current Mirror and Inverters GCMI, Balanced Operational Transconductance Amplifier BOTA, Inverting Current Conveyor 1st and 3rd Generation ICCI/ICCIII and Universal Voltage Conveyor UVC. The proposed filters work in current mode and their ideal and real models are verified in the simulation environment OrCad. The thesis is structured into five chapters including the conclusion. The first chapter gives the general characteristics of the frequency filters, types of filter functions, types of filters and general equations. The second chapter is devoted to the theory of the active elements. The third charter is about methods of designing and the fourth includes custom designed filters, including their transfer functions and the results verify their functionality in the simulation environment.
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Synthesis and Analysis of Circuits with Modern Active Elements
Koton, Jaroslav ; Vrba, Kamil (advisor)
The dissertation thesis deals with the synthesis and design of active frequency filters using current (CC) and voltage (VC) conveyors, or current active elements CMI (Current Mirror and Inverter), MCMI (Multi-output CMI) and PCA (Programmable Current Amplifier). As introduction, these active elements are described as suitable for the design of the circuits working in the voltage-, current,- ,and mixed-mode, or in pure current-mode speaking about the current active elements. The new frequency filter structures presented in this thesis using the above mentioned active elements were designed by the generalized autonomous circuit method, transformation cells and signal flow-graph theory. The generalized autonomous circuit method is based on full admittance network to which generalized active elements are connected. The described admittance networks can be used for other active elements. The next method is based on the transformation cells that subsequently are used for the design of synthetic elements with higher-order imittance. Original conditions for the design of such blocks are given that lead to maximal simplicity of the final structure with minimal number of passive and active elements. For effective usage of another method utilizing signal flow-graphs, new reduced graphs of chosen active elements are given. Their usage leads to direct function blocks synthesis with required properties. The functionality and behavior of chosen circuit solutions have been verified by analyses in simulation programs. The active elements were simulated by the universal current conveyor (UCC) or universal voltage conveyors (UVC) that were designed at the FEEC, BUT in cooperation with AMI Semiconductor Design Centre Brno with the CMOS 0.35 m technology. These active elements have been also used for the realization of chosen filter structures. The experimental measurements were performed in the in the frequency range 10 KHz to 100 MHz.
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Voltage and current reference sources
Skalický, Pavel ; Pavlík, Michal (referee) ; Háze, Jiří (advisor)
The topic of the master´s thesis are voltage and current reference sources. There is detailed description of current and voltage references, which are basic building blocks of many analog circuits, in the theoretical part. Next part of the master´s thesis is the design of a voltage reference source, the design of a voltage reference generating two voltages and a current reference source. The correct function of all circuits have been verified using simulations, especially dependence of the output voltage or current on supply voltage or dependence of the output voltage or current when the ambient temperature is changed.
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Design of current-steering DAC for differential IQ decoder
Klein, Miroslav ; Šotner, Roman (referee) ; Dřínovský, Jiří (advisor)
This master’s thesis deals with design of two channel digital to analog converter for automotive applications. In first part, different topologies of D/A converters and their properties are discussed, with focus on current steering topology. Second part deals with design of convertor topology and current steering application. In third part, all parts of designed convertor are described and simulations results are presented. The designed two channel D/A converter has differential current output with 11b resolution per channel.
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Filters with current mirrors
Kotlán, Petr ; Herencsár, Norbert (referee) ; Lattenberg, Ivo (advisor)
A second-order frequency-selection filters with current amplifier design is shortly shown in this bachelor's thesis. An autonomous circuit was modified to be conform with all rules of functionality of filters. A few version of autonomous circuit are shown i this text. The circuits were simulated by a program Microcap expecially transient and AC analysis. The current amplifier was replaced by a current mirror or more precisely by a current inverter. A direct-current and his relations to suplied harmonic signal were investigated. A deformation of a harmonic signal is unwanted. This deformation is ussualy created by the transistors in nonlinear mode. This current have to have special ratio to the alternating-current. A sixth-order filter was created by cascade connection of three second-order blocks. This more intricated circuit is correct. A correct rate of characteristic due for low-pass, high-pass and band-pass was shown thanks AC analysis.
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Solution proposal and analysis of properties of current operational amplifier in bipolar and unipolar technologies
Pawlas, Radovan ; Lattenberg, Ivo (referee) ; Vrba, Kamil (advisor)
This master thesis is about current operational amplifiers and mainly about their internal structures and possible modifications of these structures. The Current operational amplifier consists of several elementary blocks and these blocks are shortly described and used in internal structures of proposed operational amplifiers. Basic elementary blocks of the current operational amplifier are current mirror, diferentional amplifier, current source, transimpedation amplifier and additional elements of a circuit. In this thesis, several elementary structures of the operational amplifiers are introduced. Each amplifier passed through the analysis of the circuit in software MicroCap 9.0. In this software is done the simple DC analysis of the internal structure of the current operational amplifier in connection with a feedback. The solution was focused on bipolar and unipolar technology for each connection. I deal with a method of feedback connection to the operational amplifier and explore real characteristic of the appropriate amplifier in the designed feedback. In principle this design has important influence to the resulting properties of the circuit. Within the analysis of the circuits have been found, how each current operational amplifier works in a defined current range. Every type of surveyed amplifier is closely described, the internal structure is depicted and graph of current transmission of amplifier is shown. At the end of this thesis the amplifiers are compared and there are introduced their advantages and disadvantages.
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