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Differential and pseudo-differential frequency filters
Sládok, Ondřej ; Herencsár, Norbert (referee) ; Koton, Jaroslav (advisor)
This thesis deals with fully differential and pseudo-differential frequency filters. Significant emphasis is placed on the characteristics of common-mode signal. Further, the text deals with the design issue of fully-differential structure and transformation of non-differential to pseudo-differential structures. In the thesis one non-differential structure, one fully-differential and three pseudo-differential structures are proposed, one of them working in current mode. The thesis also describes the analysis from the perspective of non-ideal properties of the active element of two circuit solutions, which is trying to find the optimal solution. In each case, functionality of new solutions is verified by simulations and in several cases also by experimental measurement.
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Applications of multi-output active elements in current-mode
Maňas, Stanislav ; Jeřábek, Jan (referee) ; Šotner, Roman (advisor)
Bachelor's thesis deals with analyzing the characteristics of the block in current mode CCII and its applications. The first part is devoted to the theory of CC block, the theory of CCII block his peripheral involvement and exploration properties. The second part is a third model levels and this is carried out sensitivity and tolerance analysis of individual involvement. The third part is a block CCII surveyed as part of participation frequency filters and oscillators. One involvement has been experimentally tested. At the end of each subsection is obtained by a comparison of the characteristics of individual involvement.
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Electronically tunable frequency filters
Štěpán, Radim ; Jeřábek, Jan (referee) ; Herencsár, Norbert (advisor)
This bachelor thesis deals with a proposal of electronically controllable filters by means of modern active elemental parts such as current conveyors, transconduct amplifiers or programmable current amplifiers. The suggestion of new connection of frequency filters uses graphic chart of active and passive elements. In the introduction there is described the survey of signal flow graphs, modern active elements suitable for proposal frequency elements. The procedure of proposal of controllable frequency filter based on set typical formula of designed circuit is demonstrated as an example. On a basis of different modifications the designed circuit is made with various types of active elements. Simulation results of the program PCspice confirmed the proper working of the proposal circuits.
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The Tolerance Analysis of Filters with CDTA
Miksl, Jan ; Jeřábek, Jan (referee) ; Šotner, Roman (advisor)
The bachelor thesis deals with the concept, design, modeling, tolerance and sensitivity analysis of the KHN filter using CDTA. The first part contains theoretical introduction about filters and their general properties. Secondly, the CDTA element, its block structure, schematic symbol as well as its circuit features are defined. Standard KHN filter structure with operational amplifiers is simulated. Results of this simulation are used for comparison with simulations results of CDTA KHN filter structure. The multifunctional CDTA KHN filter structure is simulated using ideal CDTA models, third-level models and models based on professional macromodels of attainable components (AD 844, MAX 435). Then tolerance and sensitivity analyses are explained and described. The following section discusses ways of modifying the structure and design KHN structure with CDTA models 3rd level. In the last chapter the circuit is optimized using PSpice and the attention is focused on achieving the best possible involvement of the typical characteristics of the elements of tolerance. In conclusion, the results of simulations are evaluated, compared the characteristics of circuit before and after optimization, and mention the advantages and disadvantages of filter elements with CDTA.
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Design of frequency filters with active current elements
Hort, Jiří ; Jeřábek, Jan (referee) ; Vrba, Kamil (advisor)
This bachelor's thesis deal with designing frequency filters with current active elements. Preamble is devoted to description of basic properties and division of filters. Next part presents some way of designing frequency filter. The element CMI (Current Mirror and Inverter) seems like optimal possible solution for application working in purely current mode. To design purposes serves generalized version GCMI. This thesis describes way of designing the autonomous circuit based on full admitance nets with one and two active elements CMI. Several autonomous circuits with four or five passive elements are derived from every admitance network. Individual autonomous circuits are then presented in chart with their characteristic equation. In conclusion is shown design of selected multifunction frequency filter working in current mode as in voltage mode together with characterization for its various transmission functions.
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Electronically adjustable active elements for the realization of oscillators and function generators
Bokůvka, Tomáš ; Jeřábek, Jan (referee) ; Polák, Josef (advisor)
This thesis is focused on the design, analysis and realization of new oscillator and generator circuits using electronically adjustable active elements. In the opening discussion the aspects of distribution, proposal, properties and oscillation conditions of generators and oscillators are theoretically described. Next, there are presented some electronically adjustable active elements which appear to be suitable for construction of the oscillators and generators. This covers in particular the Operational Transconductance Amplifier OTA, Voltage Control Amplifier VCA and Digitally Adjustable Current Amplifier DACA. Using these elements the six oscillators and two functional generators are presented. Simulation results and design methods are included. Next part is focused on practical realization and measurement. At the end of the thesis the measurement and simulation results are discussed and compared.
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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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Universal precision rectifiers with current active elements
Ryšavý, Lukáš ; Jeřábek, Jan (referee) ; Langhammer, Lukáš (advisor)
In this thesis new circuit solutions of universal precision rectifiers with current active elements are proposed. Based on the knowledge of current active elements, universal precision rectifiers and adverse impacts on these circuits new circuit solutions are proposed. These circuits are then simulated and compared with the known circuits of precision rectifiers. In concusion two original circuits and two proposed circuit solutions based on original ones are implemented, their properties are experimentally measured and their function are verified. The main active element in the original circuit are the OPA or THS, the proposed circuits are used the OPA and THS and the universal current conveyor, which offers a wide range of application use and realization of different variations of active current elements.
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Analysis, features and applications of available current mode multipliers
Miksl, Jan ; Jeřábek, Jan (referee) ; Šotner, Roman (advisor)
The diploma thesis deals with analysis, validation, measurement of parameters of the commercially available current multiplies (namely the EL2082 and EL4083) and their applications in practice. Control analysis are carried out in OrCAD PSpice program and compared with values from datasheets. Control analysis are focused on AC and DC characteristics of these active blocks. There are discusses the input impedance, the output impedance, the current gain and the possibility of electronic adjusting. The parameters of the elements were verified by measurements. Proposals for circuit applications (selective circuit, oscillator, frequency filter) with EL2082 and EL4083 are presented and analyzed in the program OrCAD. Three oscillator circuit designs are experimentally tested and the results are compared with the theoretical expectations and simulations in OrCAD. The possibility of electronic control for oscillators is examined. Also the sensitivity and the tolerance analysis are carried out. The constructional details of oscillators are presented at the end of this work.
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Frequency filters using current active elements
Homola, Radek ; Lattenberg, Ivo (referee) ; Koton, Jaroslav (advisor)
This master´s thesis is about MO-CF, DCCA and CC frequency filters with current active elements proposal. Current active elements, their features, structure and utilization are shown in introduction. A progress propose of universal filter is described in thesis. With the use of active elements has been established an universal filter with basic parameter changes capability (quality and limit frequency). SNAP software was used in this propose and the characteristics simulation have been done in OrCad-PSpice. For control changes of quality and limit frequency was used active element DCCA. The main circuit board of universal controlled filter was made with the EAGLE software. Created sample was measured for each type of filter, the different quality and limit frequency. These values were compared with simulated values of the filter.
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