National Repository of Grey Literature 5 records found  Search took 0.01 seconds. 
Low-frequency active threshold-less voltage detectors
Litovska, Anna ; Theumer, Radek (referee) ; Šotner, Roman (advisor)
This bachelor thesis deals with various solutions of the active topology of voltage detectors and rectifiers that do not use diodes. Specifically, it focuses on discrete detectors with multipliers and voltage-to-current converters, a discrete peak detector with transconductors, and an integrated RMS detector with an AD734 multiplier. This thesis includes theoretical design of parameters of circuits for required features as well as verification by computer analysis (PSpice) and experimental measurement. This work includes documentation for construction of the product, including the block arrangement and the design of the printed circuit board.
Fractional-order integrator and its application in FLF fractional-order frequency filter
Theumer, Radek ; Langhammer, Lukáš
The main aim of this paper is to introduce the proposal of fractional integrator by approximation of the integer-order follow-the-leader-feedback topology (FLF). Current differencing transconductance amplifier (CDTA) is used in the integrator due to the higher versatility of this building block. The proposed integrator is also implemented to the frequency filter, creating a fractional-order frequency filter in FLF topology. The main advantage of this circuit is its electronic controllability. The resulting circuits (integrator and filter) are simulated in OrCAD using a transistor models in TSMC 0.18 um technology.
Design of basic analogue building blocks with fractional-order transfer
Theumer, Radek ; Staněk, Miroslav (referee) ; Langhammer, Lukáš (advisor)
This diploma thesis is focused on design of the analogue circuit structures with integer-order and fractional-order transfer. The ways in which fractional-order transfer functions can be achieved are mentioned in the introduction. Two basic building blocks with the ability to control its transfer function order and frequency, such as integrator and differentiator respectively, were designed. A non-traditional active element was used in proposed analogue building blocks. In addition, the inner structure of this active element has been improved to provide the ability to control another suitable parameters. Aplication of the proposed fractional-order integrators is presented by employing into the frequency filter. Simulations are performed with help of transistor-level models of two different technologies: CMOS TSMC 0,18 um in the OrCAD Pspice software and I3T25 in the CADENCE Virtuoso software too. All proposed circuit structures are realized on the printed circuit board (PCB) and then measured experimentally. The last part is focused on comparative measurements of the filters with fractional-order integrator proposed by another author.
Synthesis Of Electronically Reconfigurable 3rd-Order Flf-Os Filter In Singleended And Fully-Diferential Design
Theumer, Radek
This paper deals with a proposal of 3rd-order single-ended and fully-differential frequency filters based on the follow-the-leader-feedback topology with the output summation (FLF-OS) working in the current mode. The main feature of both of these filtering structures is an ability of the electronic reconfiguration of their transfer functions. Active elements used for the filter design are implemented by transconductance amplifiers, current amplifiers and current followers. Simulation results of available transfer functions, their tunability and comparison of both circuits are presented.
Synthesis of frequency filters with ability of the electronic reconfiguration
Theumer, Radek ; Šotner, Roman (referee) ; Langhammer, Lukáš (advisor)
This bachelor thesis deals with proposal of frequency filters providing electronic controllability of its transfer function. The main aim was to propose new filtering structures working in voltage and current mode based on suitable proposal methods. Active elements are implemented by available operational transconductance amplifiers, current amplifiers and conveyors, eventually voltage amplifiers. Four different active controllable filters are presented. Their function is simulated in software PSpice with help of models at transistor level in comparison with ideal behavior (idealized models). Two designed filtering structures were chosen and complemented on parasitic, sensitivity, stability, temperature analysis and Monte Carlo analysis. These circuits were realized on PCB. Measurement results are presented at the end of thesis, including comparison with simulations.