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Laboratory task dedicated to filters with switched capacitors
Čipl, Jan ; Šotner, Roman (referee) ; Petržela, Jiří (advisor)
This semestral thesis deals with the issue of analog frequency filters, their division and voltage transmission characteristics of filters. Furthermore, this work is focused on the description of filters operating on the basis of switched capacitances. This work also includes simulations, which are the first draft of a laboratory preparation for teaching. The simulations were performed in the Orcad Pspice program
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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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Electronically controlled active 2-nd order filter
Ševčík, Břetislav ; Petržela, Jiří (referee) ; Šotner, Roman (advisor)
The diploma thesis deals with the modern design of the control circuits for digital potentiometers and their application in analog systems. The concept of the digital control is demonstrated on the electronically controlled active 2-nd order filter and programmable oscillator. The proposed design of the active filter describes a programmable active 2-nd order filter Sallen-Key. In this circuit it is possible independently programme cut-off frequency, Q factor and type of approximation with very good accuracy. The circuits of the designed filter and designed oscillator are simulated in PSpice (OrCAD), parasite effects and effects of the real parts are studied. Properties simulated circuits are compare with experimental results. These results appreciate quality and efficiency of the digitally controlled potentiometers in dependence on variable input circuit parameters. Integral part of this project is author’s universal control program called Digipot and comunications interface for many types of digital potentiometers with I2C, SPI or Up/Down interface. It is possible to use this device for many applications. The constructional details of the filter are presented at the end of this work. The software equipment is availability on enclosed CD.
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Electronically controlled active 2-nd order filter
Ševčík, Břetislav ; Petržela, Jiří (referee) ; Šotner, Roman (advisor)
The diploma thesis deals with the modern design of the control circuits for digital potentiometers and their application in analog systems. The concept of the digital control is demonstrated on the electronically controlled active 2-nd order filter and programmable oscillator. The proposed design of the active filter describes a programmable active 2-nd order filter Sallen-Key. In this circuit it is possible independently programme cut-off frequency, Q factor and type of approximation with very good accuracy. The circuits of the designed filter and designed oscillator are simulated in PSpice (OrCAD), parasite effects and effects of the real parts are studied. Properties simulated circuits are compare with experimental results. These results appreciate quality and efficiency of the digitally controlled potentiometers in dependence on variable input circuit parameters. Integral part of this project is author’s universal control program called Digipot and comunications interface for many types of digital potentiometers with I2C, SPI or Up/Down interface. It is possible to use this device for many applications. The constructional details of the filter are presented at the end of this work. The software equipment is availability on enclosed CD.
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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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