Josef Punčochář

VSB - Technical University of Ostrava · Department of Electrical Engineering

Operational Amplifiers in Electronics - basic principles and applications. More economy copy - see "linked data". Opravy a komentáře viz: https://www.researchgate.net/publication/372187006_Poznamky_ke_knizedocx

After reading this book, the reader should be able to analyze and construct electronic circuits (amplifiers, filters, oscillators, converters, etc.) with real active circuit elements: Operational amplifier; Transconductance amplifier; Transimpedance amplifier; Current conveyor; Analog multiplier. The better copy see: https://www.researchgate.net/pu...

The Wien – bridge oscillator is probably the most widely used type of RC oscillator. In a standard analysis it is assumed that the used amplifier is ideal. In this paper is presented the Wien – bridge oscillator with different real amplifiers. It would be better to talk about “half – bridge”. The half – bridge (R1C1 + R2C2 “Wien – divider”) in the...

This work is a "story" about a selected problem from electronics - creating large values of capacities and inductances. The use of these elements is demonstrated even for cases where they do not have ideal properties. The chosen analytical procedures result from the motto: "An engineer (expert) must remain an engineer (expert) even when the compute...

This article describes an integrator with a real op amp.

Methodology for describing the slew rate of OPA as a function of the input signal levels.

Since 1976, I have published a number of articles in the magazine "Sdělovací technika", which was reviewed at the time. It's probably not worth "posting" entire articles on the web these days. But some results may be interesting even now. Fig. 1 shows a practical connection of a corrector with an asymmetrical double T bridge in feedback.

Change of time constant.

The textbook manuscript was created in 2012, i.e. about 11 years ago. I used the book in my teaching until this year (2023) - And so, since 2012, several corrections have certainly been "accumulated", but also new knowledge. In the following text, I will proceed according to pagination from the "electronic form", correct some errors, or refer to ne...

Rukopis prvního vydání (1996) vznikal v roce 1994, tedy asi před 30 lety. 5. vydání (tištěné) vyšlo v roce 2002 a v elektronické podobě v roce 2011. V každém vydání do roku 2002 byly odstraněny některé chyby, případně doplněny některé pasáže. Knihu jsem až do letošního roku (2023) využíval při výuce- A tak se od roku 2002 jistě “nastřádalo” někol...

This work is directly related to materials: https://www.researchgate.net/publication/356415458_FET_QUIESCENT_POINT https://www.researchgate.net/publication/358214926_FET_-_common-source_configuration . https://www.researchgate.net/publication/358397676_FET_-_common_-_gate_configuration During my 29 years of teaching experience, I have often found...

This work is directly related to materials: https://www.researchgate.net/publication/356415458_FET_QUIESCENT_POINT https://www.researchgate.net/publication/358214926_FET_-_common-source_configuration . During my 29 years of teaching experience, I have often found that students who have relatively easily mastered "working with BJT" have difficulty...

This work is directly related to the material: FET QUIESCENT POINT; https://www.researchgate.net/publication/356415458_FET_QUIESCENT_POINT During my 29 years of teaching experience, I have often found that students who have relatively easily mastered "working with BJT" have difficulty coping with the topic of FET transistors. Setting a working poin...

During my 29 years of teaching experience, I have often found that students who have relatively easily mastered "working with BJT" have difficulty coping with the tema of FET transistors. Setting a working point in particular is often a problem. In normal teaching, I tried to clarify this problem in lectures. In today's more problematic - often dis...

This material (teaching method) was created at the time of teaching "online". The aim is the learning "in context". I hope it will allow students to understand well the basic considerations when designing simple amplifiers with BJT transistors and facilitate the study of more demanding problems.

To this article (circuit) is very interesting discussion (comments), see: https://www.researchgate.net/publication/348655150_AC_amplifiers_with_ultra-low_corner_frequency_by_using_bootstrapping/comments

Czech - English text. Je poukázáno na problémy v součtovém zapojení operačního zesilovače s reálnými vlastnostmi. Problems in the summing connection of an operational amplifier with real properties are pointed out. Material created for the purpose of teaching ONLINE.

"Ekonomičtější" verze publikace.

This text was created for the need of distance learning in today's problematic times. Assumes a student with adequate knowledge of the basics of electronics. It describes the basic amplification structures - including extensive materials suitable for discussion.

During the debate with Lutz von Wangenheim about "Filters studies", I found that suitable solution with cascade connection LP2 and HP2 is a bit simple (:-)) and this could lead to simplified considerations about filters design. Therefore, I do a small change in the input conditions.

Tasks of type to design low-pass filter (Butterworth, Bessel, and Chebyshev) are somewhat easy actually. In today's difficult times, it is necessary to offer students a slightly different view of the problem. No "how only" but also "why this solution". Where is the starting point? It is the English version of the Czech material "Filtry studie"

Úkoly typu navrhněte dolní (horní) propust (Butterworth, Bessel, Čebyšev) jsou vlastně velmi jednoduché. Podstatně složitější může být, proč takový filtr vůbec navrhovat. Na rozboru jednoduché situace demonstrujeme několik metod řešení.

This short work is a "prelude" to work: Research The second journey: from the linear OPA model to the basic p... It is part of the my project: "Passing" of courses

I would like to point out one possible way to get a topic for an article. It is “qualified distrust”. I suppose it will be difficult reading, but interesting too, I hope. At the end of the last century (millennium) I saw the circuit diagram in Fig. 1 – here taken from [1]. The acoustic frequency range was featured for this circuit – however “lazy”...

It will be investigate input resistances of a "classic" OPA input stage with quiescent current I Q = I 1 + I 2

Supplement to the article “Band Stop Filter with a Synthetic Inductor with Series Resistance and a Real Operational Amplifier”

http://advances.utc.sk/index.php/AEEE/article/view/2317; This paper deals with application of simple synthetic inductor with series resistance (non-ideal gyrator). Those inductors are seldom used. But if we use this inductor in the arm of bridge the circuit is able to work very well. In this way we can get band stop filter with good performance....

The properties of the integrator with the real OPA are analyzed.

Loads of current source - the consequence of the discussion from RG (Where is the ”dynamic load”? – the question of Cyril Mechkov)

If we want large gain , we need large supply voltage. What about it?

Addition to article: Solution of the linear circuits by Signal Flow Graphs

We will describe the algorithm for solution of linear circuits by means of signal flow graphs - a process in which it is not necessary division by some members of the equations before merging the graphs of the sub-parts of the circuit. Such a procedure will allow establishing an algorithm for the direct compilation of a signal flow graph for the ci...

An interesting analysis (in my opinion) of an inverting structure with an operational amplifier. The circuit is solved by various methods. Everyone can compare each other. The structure is, of course, inverting. Sorry for error in Fig.1 and Fig.2.

Wienův oscilátor je snad nejpoužívanějším typem oscilátoru RC. Při analýze tohoto obvodu se běžně předpokládá, že použitý zesilovač je ideální. V praxi se ovšem ukazuje, že tento předpoklad je splněn pouze pro nečekaně nízké frekvence. V článku jsou popsány vlastnosti Wienova oscilátoru s reálným zesilovačem, který je realizován klasickým operačním...

Dynamic properties of operational amplifiers and their tentative derivation from catalog data V článku předložený matematický aparát umožňuje stanovit na základě katalogových údajů další zajímavé údaje, které popisují reálné vlastnosti operačního zesilovače.

The article describes bandpass filtersw that allow to achieve a high quality factor even for signals with amplitude of the order of volts. V článku jsou popisovány pásmové propusti, které umožňují dosáhnout vysokého činitele jakosti i pro signály s amplitudou řádu voltů.

Relatively simple circuit whose output frequency is determined by the ratio of two input voltages.

Very simple current source which do not need a "rail to rail output" type OPA2.

I present a brief supplement to the distortion in amplifiers with BJT with biasing "from the collector to the base." The seventh journey – short look at nonlinearities in basic BJT amplifiers

It would seem that determining nonlinear distortion of the amplifier is difficult. But for BJT, if we know well the properties of the function exp (x), it's relatively easy. Let's try it.

Better pdf copy of the book: Theory of electronic circuits

Compendium from experimental results (3 x famous 741) - from Czech primary article. Supplement to: The sixth journey (short): Oscillators with all-pass filters

With the all-pass filter we are able to work very well. They are simple and easily tunable - it is evident that provide a large range of application. One possible use are oscillators with them.

This probably is not rocket research, but didactic experiment. We want to look into an unreliable country of "R filters"only a little.

This probably is not rocket research, but didactic experiment (desperate) about teaching in context. Now about BP filters for "high input voltages".

This probably is not rocket research, but didactic experiment (desperate) about teaching in context. We try just to show that we must to study in context. Isolated knowledge (of anything) without context ("insular knowledge)" does not lead to productive thinking - rather lead us to a dead end.

This is no a super research. We try just to show that we must to study problems in context. Isolated knowledge (of anything) without context ("insular knowledge)" does not lead to productive thinking - rather lead us to a dead end. At this point, however, we can show just the basics. But properly absorbed the primers can be the best companion and r...

This probably is not rocket research, but didactic experiment (desperate) about teaching in context. Below given knowledge are necessary but certainly not sufficient for "circuit experts". We try to show it on the example the shortest study way from electrotechnic basis to modern operational amplifiers (OPAs). Isolated knowledge (of anything) with...

Materiál obsahuje stručný popis základních zesilovacích struktur. The material contains a brief description of the basic amplifying structures.

The classical differential input part of OZ - basic considerations V práci jsou na malém prostoru shrnuty základní vlastnosti ("lineární" a některé "nelineární") vstupního diferenčního dílu klasického operačního zesilovače.

Jedná se o habilitační práci odevzdanou v dubnu 1996.

Jedná se o disertační práci ze září 1995, která se zabývá problematikou operačních zesilovačů. This is a dissertation thesis of September 1995, which deals with the problem of operational amplifiers.

Chování OZ v časové oblasti po překonání slew rate oblasti - tedy nelineární oblasti děje.

Základní úvahy pro aproximaci tří nejběžnějších typů filtrů. Basic considerations for approximation of the three most common types of filters.

Základní úvahy při řešení lineárních (linearizovaných) elektronických obvodů. Basic considerations for the solution of linear (linearized) electronic circuits.

Current source with towing power supply using a parallel stabilizer

Time ratios while reducing consumption of operational amplifiers Abstrakt: V článku jsou popisovány principy a vlastnosti operačních zesilovačů při snižování proudového odběru I CC , jejich " dynamika " – a to jak v souvislosti s dobou zotavení t Z tak i v souvislosti s využitím tohoto režimu pro přepínání signálů (multiplex). Současně jsou stručně...

Astable circuit with current source with bipolar transistor controlled by voltage

Abstrakt V elektrotechnice lze využívat pro analýzu obvodů různé analytické nástroje. Možnou metodou je i analýza pomocí grafů signálových toků. Analýza elektronických obvodů pomocí MB grafů je podrobně popsána v [2, 3]. Odvozeny jsou modely (grafy) pasívních prvků (R, L, C) i známých zesilovacích struktur. Nejsou však popsány modely transformátoru...

Circuit solutions by means of signal flow graphs

Základy elektroniky včetně příkladů. Basics of electronics including examples.

In electrical engineering we can use various analytical tools for the circuit analysis. One possible method is the analysis by means of signal flow graphs. Analysis of electronic circuits using the MB graph is in detail described in [2, 3]. There are derived MB models (graphs) of passive elements (R, L, C) and of known amplifier structures, too. Ho...

There will be described a single methodology clarifying the signal models of bipolar and unipolar transistors in this article. The methodology is established for undergraduate studies, the same starting point can be used for subsequent stages of study. It allows a substantial reduction in time allocation while maintaining the final volume of inform...

DERIVATION OF SIGNAL FLOW GRAPHS OF AMPLIFYING STRUCTURES BY MEANS OF THEIR ADMITANCE MODELS V literatuře je uváděn algoritmus řešení obvodů s orientovanými grafy signálových toků s využitím intuitivních modelů aktivních prvků. Postup je vhodný pro prvky s nulovou výstupní impedancí. Je potřebné hledat algoritmus, který zajistí korektní zahrnutí vš...

Operational Amplifier Recovery Time Abstrakt: V článku je diskutována doba zotavení operačních zesilovačů v souvislosti s jejich konstrukcí. Primární příčinou konečné doby zotavení je saturace kteréhokoliv tranzistoru ve struktuře OZ. Velký význam má tento parametr tam, kde je OZ používán jako komparátor nebo je nucen rychle obnovit svou funkci ze...

1. vyd. 150 výt.

Práce, u níž jsem byl školitelem, se zabývá problematikou pásmových zádrží s reálnými operačními zesilovači.

1. vyd. "Skripta byla vydána v rámci projektu OPRLZ CZ.04.1.03/3.2.15.1/0020 Rozvoj oboru Biomedicínská technika a zvýšení uplatnitelnosti jeho absolventů na trhu práce v návaznosti na zákon č. 96/2004 Sb."--Rub tit. s. 150 výt.

In the course of an op amps properties study, concretely the study of Voltage Feedback Amplifiers (VFA or VFB) based on Current Feedback Amplifiers structures (CFA or CFB; more exactly these are transadmitance amplifiers), I happened on different methods of op amps phase characteristic depiction (frequency response plots). These depiction styles (o...

This paper deals with an analysis of low-pass Sallen and Key filter. It describes the influence of gain-bandwidth product and output resistance of real operational amplifier over frequency response of the circuit and possibly circuit modification - too overcome (partly) the influence of the output resistance.

It is solved a step response of inverting amplifier for large-step input voltages which cannot be done by means of the linear analysisi only.

This paper deals with influence of the first pole of op amp upon properties of a bandstop filter. Generalised voltage analysis is used for calculation.

There are determined in the paper the admitance matrices of some modern electronic device: operational amplifiers, current conveyors, current feedback amplifiers, transadmittance amplifiers and Norton amplifiers. Thus we can use the generalized nodal voltage analysis for solving of linear structures with the named amplifiers.

Kniha přehledně a stručně popisuje běžné zesilovací struktury. The book clearly and briefly describes common amplification structures.

Only four dependent sources can be used to develop models for all active elements encountered in modern circuit analysis and synthesis, too. If we can by means of just one active element construct the all four dependent sources, we can call this element general-purpose or simple universal active element (prime element). For linear integrated circu...

Designs using op amps have assumed that the op amps have ideal parameters. In fact, op amps are never ideal. Some of their characteristics are frequency dependent (frequency response, frequency-domain). Another parameters are non-linear, etc. An important non-linear parameter is a slew rate - the maximum possible rate of change of output voltage pe...

1. vyd. Dot. 2005 Pro posluchače 3. a 5. ročníku FEI

In a standard text book analysis of the Wien-bridge oscillator it is assumed that the amplifier used is ideal. In this paper is presented oscillator with a real single-pole operational amplifier. The analysis will be done by means of the generalised nodal voltage analysis.

Generalized nodal voltage analysis and nullor nodal analysis are very simple and useful in the analysis of linear active networks. It is evident that for the nodal voltage analysis of networks with modern integrated electronic devices it would be known their admittance models (matrices) or nullor models. That is why we will determine the admittance...

This paper describes one practical realization of the narrow band-reject (notch) filter with a real op amp. It will be done the analysis of op amp gain-bandwidth-product on the properties of the notch-filter.

Generalized nodal voltage analysis and nullor nodal analysis are very simple and useful in the analysis of linear active networks (networks with active n-terminals). It is evident (see INTRODUCTION) that for the generalized voltage analysis it would be known an admittance matrix of any electrical devices, for the nullor nodal analysis it would be k...

In this paper we argue against some parts of papers [1] and [2] which are engaged in determining of stability by means of " classical " procedures. It is always possible to determine the stability in this way. But we must respect the obligatory pole of an amplifier that always exists and describes a fact that a noise-bandwidth of any electrical dev...

Generalized nodal voltage analysis and nullor nodal analysis are very simple and useful in the analysis of linear active networks (networks with active n-terminals). It is evident (see INTRODUCTION) that for the generalized voltage analysis it would be known an admittance matrix of any electrical devices, for the nullor nodal analysis it would be k...

This paper was written to provide an introduction to the basic concepts of modern active-circuit analysis-by means of basic properties of linear networks. These are: Ohm´s law, Kirchhoff´s voltage and current laws, superposition, two-port network conception, nullor conception and generalized nodal voltage conception. It is supposed that all know th...