DEPARTMENT OF RADIO ELECTRONICS
Acoustic relay on field effect transistor
Explanatory note
for course work in the discipline:
FKRE 467.740.001.PZ
Completed Art. gr. 220541 Galkin Y.A.
Head Ovchinnikov A.V.
Federal Agency for Education
Tula State University
Department of Radio Electronics
for course work on the course
“Fundamentals of computer design and modeling of electronic distribution systems”
student gr. 220541 Galkin Y.A.
1. Topic: Acoustic relay on a field-effect transistor
2. Initial data: Electrical circuit diagram.The device is intended for indoor use at operating air temperatures of +10 0+ 40 0 ± 5 0 C, atmospheric pressure 86.6-106.7 kPa and the upper value of relative humidity 80% at a temperature of 25 0 C.MTBF - 30 years. Reliability after 5000 operating hours should be greater than 0.8.
3. List of issues that require elaboration Develop a printed circuit board for this device, select board and case materials, calculate the design parameters of the board, calculate manufacturability, and calculate reliability.
4. List of graphic material: Electrical circuit diagram, printed circuit board.
5. Main bibliography: Akimov I.N. “Resistors, Capacitors. Directory", Romanycheva E.T. and others. Development and execution of design documentation for REA: reference book, Design and production of printed circuit boards: Textbook. allowance/ L.P. Semenov.
Accepted the task Galkin Ya. A.
(signature) (full name)
Issued the task Ovchinnikov A.V.
(signature) (full name)
Annotation
In this course project, I analyze the technical specifications, based on it I make a choice of manufacturing method printed circuit board, calculation of design and technological parameters of a printed circuit board, selection of elements and materials, as well as calculation of reliability.
In addition to the calculation part of the course project, a technological process for manufacturing a printed circuit board is developed and operational cards for the manufacturing process of a printed circuit board are filled out.
All documentation must comply with ESKD standards.
The explanatory note contains 25 sheets.
Electrical circuit diagram of an acoustic relay on a field-effect transistor (A3 format);
List of elements (A4 format).
Introduction……………………………………………………………………………….6
- Analysis of technical specifications……………………………………...7
- Selection and justification of the elements and materials used…..9
- Selection and justification of design solutions………………..10
- Selection and justification of the method of manufacturing a printed circuit board....11
- Description of the device design………………………………..12
- Calculation of design manufacturability………………………..….15
- Calculation of design parameters of a printed circuit board……….….18
- Reliability calculation………………………………………….….20
- Conclusion…………………………………………………….….23
List of references……………………………….….24
Introduction
Design documentation (CD) is a set of design documents containing, depending on their purpose, the data necessary for the development, manufacture, control, acceptance, delivery, operation and repair of a product. The design documentation contains not only drawings, but also describes methods for creating individual parts, as well as assembling assemblies.
The main task of design is selection optimal solutions under certain requirements specified in the technical specifications (specifications). Such requirements may be: price, reliability, prevalence (of materials and (or) elements), etc.
The design of radio-electronic equipment (REA) differs from others in the peculiarity of the internal connections formed between parts: in addition to spatial and mechanical ones, complex electrical, thermal and electromagnetic connections must be established. This feature is so significant that it separates the design of electronic equipment into a separate engineering direction.
- Analysis of technical specifications
In this course work it is required to develop an acoustic relay based on a field-effect transistor. To assemble the electronic part of the device, a single-sided printed circuit board is used, which is fixed in a plastic case.
This relay has the following parameters:
The body of the device should be comfortable to hold in your hands, and the controls should be located so that it is not difficult for the operator to control the model.
The device must operate reliably under the following conditions:
This device circuit uses a microphone, as well as its amplifier based on transistor VT1 to open the relay, the amplification power is regulated using trimming resistor R6. The relay can also be opened by pressing the S1 button once.
The opening is carried out using the charge accumulated on capacitor C5. After opening, this capacitor, as well as capacitor C9 (it regulates the opening time of the relay) are discharged through resistors R10, R11. Transistor VT4 is also used to speed up discharge.
When the relay opens (transistor VT5 opens), the current in circuit R12, HL1 stops, the microphone amplifier is de-energized, and the voltage on capacitor C4 drops to 0.
The relay closes after the VT5 transistor closes. After closing, the power to the LED and microphone amplifier is restored - the device returns to its original state.
All elements are quite reliable in use, inexpensive and meet all operational and electrical requirements, and also have acceptable dimensions.
- Selection and justification of elements and materials.
2.1 Selection of resistors.
To manufacture the device, we will select the MLT type resistors, the most common in industrial production, with a rated dissipation power of 0.125 W; these resistors are designed to operate at temperatures environment-60 h +70°C and relative humidity up to 98% at a temperature of +35°C, which satisfies the technical specifications. Some resistors, according to technical specifications, require more power; in accordance with the requirements, we select more powerful ones.
We choose the tuning resistor type SP3 - 19.
Also, to save space, I used resistors K1-12 - open-frame.
The nominal resistance of all resistors is indicated in the list of elements. They correspond to the standard range of resistances recommended for of this type resistors.
2.2 Selection of capacitors.
We choose electrolytic capacitors of the K50 type, because they are quite cheap and common. If possible, to reduce the size, we choose open-frame capacitors of the K10 type. High voltage capacitors are also required, we select capacitors that satisfy this condition - K73. We chose them based on the fact that they are suitable for the rated voltage and have a relatively small size, and they are also suitable for the operating temperature range. Electrolytic capacitors are oxide-electrolytic capacitors designed for operation in direct and pulsed current circuits with ambient temperatures of -20h +70°C and have a minimum operating time of 5000 hours, designed for mounting on a printed circuit board.
2.3 LED selection.
The red LED HL1 AL307 is used as an indicator of the operation of the device, as it is the cheapest, simplest and most reliable.
2.4 Selection of housing material.
We will choose a molded plastic case as the lightest, providing sufficient structural strength and small dimensions in accordance with the technical specifications.
2.6 Selecting a power system.
This device is powered from a network ~220V, 50 Hz, through the load.
2.7 Selecting printed circuit board material.
IN this device A printed circuit board made of fiberglass is used. This material was taken as it is often used in production. It is mechanically stronger, and also has weakened capacitive connections compared to other materials (for example, getinax).
3. Selection and justification of the design solution.
Printed wiring is widely used in the design of electronic power distribution systems. It is made in the form of printed circuit boards or flexible printed cables. A dielectric or dielectric-coated metal is used as a base for a printed circuit board, and a dielectric is used for flexible printed cables. To make printed conductors, the dielectric is often covered with copper foil with a thickness of 35...50 µm, or copper or nickel foil with a thickness of 5...1 0 µm. We are not able to use a single-sided printed circuit board; due to the complexity of the device, we use a double-sided one. Printed installation is performed using the basic combined positive method (with pre-drilling holes). This method based on the processes of galvanic copper deposition.
When determining the board area, dimensions and aspect ratio, the following factors were taken into account: the area of the elements placed on the board and the area of auxiliary zones; acceptable dimensions in terms of technological capabilities and operating conditions. When determining the area of the board, the total area of the elements installed on it is multiplied by a disintegration coefficient equal to 1.5...3, and the area of auxiliary zones is added to this area. Disintegration is carried out in order to provide clearances for placing communication lines and heat removal. Excessive reduction of the gaps between elements on the board can lead to an increase in thermal stress.
Together with the other parts, the board is placed in the case with mounting screws.
Since the specific power dissipation is low, natural cooling is used.
4. Selection and justification of the printed circuit board manufacturing method.
Depending on the number of applied conductive layers, printed circuit boards (PCBs) are divided into single-sided, double-sided and multilayer. Double-sided PPs are made on a relief cast base without metallization or with metallization. They are used for installation of household radio equipment, power supplies and communication equipment.
Methods for manufacturing PP are divided into two groups: subtractive and additive, as well as combined (mixed). In subtractive methods, foil dielectrics are used as a base for printed wiring, on which a conductive pattern is formed by removing foil from non-conducting areas. Additive methods are based on the selective deposition of a conductive coating, onto which a layer of an adhesive composition can first be applied.
Despite the advantages, the use of the additive method in the mass production of PP is limited by the low productivity of the chemical metallization process, the intense effect of electrolytes on the dielectric, and the difficulty of obtaining metal coatings with good adhesion. Subtractive technology is dominant in these conditions, but the most advantageous (since it takes advantages from both methods) is combined.
The main methods used in industry to create a printed circuit design are offset printing, grid printing and photo printing. The choice of method is determined by the design of the PCB, the required accuracy and installation density, equipment performance and process efficiency.
Since the PCB is double-sided, the installation density is not high (the minimum width of the conductors is not less than 1 mm) and the production is definitely serial, then in this course work the board is manufactured using a mesh-chemical method. This method is widely used in mass and serial production of printed circuit boards made of fiberglass. As a rule, the production of circuit boards is carried out on universal mechanized lines, consisting of individual automatic and semi-automatic machines that consistently perform technological process operations.
The entire process of manufacturing printed circuit boards consists of the following main technological operations:
1. Cutting material and making blank boards;
2. Drawing the diagram with acid-resistant paint;
3. Etching;
4. Removing the protective layer of paint;
5. Kratsovka;
6. Application of a protective epoxy mask;
7. Hot tinning of soldering points;
8. Stamping;
9. Marking;
10. Board control.
In order to maximize mechanization and automation of the process, all printed circuit boards are manufactured (processed on line) on one of the dimensional technological blanks.
The technological process is described in more detail in the Appendix.
5. Description of the device design.
The device is made in accordance with the technical specifications, placed in a housing made of plastic. Case dimensions 1359545. All radio elements are placed on a printed circuit board located horizontally. The board is attached to the case using a screw connection. The housing cover is attached to the housing with two screws.
A groove is cut out on the side of the case for the outlet of the network cable. There is a hole drilled in the top of the case for installation. LED indicator, there is also a slot that facilitates the access of sound waves to the speaker located inside the device. To reduce the cost of execution, I chose a red LED.
6. Calculation of design manufacturability.
In practice, due to the fact that manufacturability is one of the most important characteristics, there is a need to evaluate it when choosing the best option its manufacture from several possible ones.
There are many different indicators on the basis of which both the overall and its individual components are assessed. Let's look at some of them.
6.1 Distribution of parts by succession
Based on Table 1, the following coefficients are determined:
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Indicators |
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Specially manufactured |
Normal |
Purchased |
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For this |
Borrowed bathrooms from other products, |
fastenings, |
Fasteners, |
Non-standard |
Standard |
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quantity names, D |
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quantity parts, W |
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Nsh.n.— number of non-fastening parts;
Nsh.p.s.— number of standard parts;
Nsh.k.— number of fasteners;
Nsh.v.- the number of all parts.
Nsh.z.- the number of parts borrowed from other products;
Nsh.k.- number of fasteners.
Nsh.s.— the number of parts manufactured specifically for this product;
Nd.s.- the number of varieties of parts manufactured specifically for this product.
Nsh.p.— number of non-standard parts.
- Normalization factor
2. Borrowing ratio:
3. Repeatability factor:
4. Continuity rate:
6.2 Distribution of nodes by complexity and interchangeability within a node
Here, based on Table 2, the following coefficients are determined:
1. Assembly complexity factor:
2. Interchangeability coefficient within nodes:
7 . Calculation of design parameters of a printed circuit board.
As initial data, you must have: the design of the printed circuit board, the method of obtaining the pattern, the minimum distance between the holes, the pitch of the coordinate grid, the shape of the contact pads, the mounting density. As a result, the diameter of the contact pad, the width of the conductor, and the distance between the conductive elements are calculated.
The board is manufactured using the mesh-chemical method according to the second class of accuracy. Its main design parameters are as follows:
Minimum value of the nominal conductor width t H =1 mm;
Nominal distance between conductors S H =0.5 mm;
Ratio of hole diameter to board thickness ≥ 0.33;
Hole tolerance ∆d=±0.05 mm;
Conductor width tolerance mm;
Tolerance for hole location mm;
Tolerance for the location of contact pads mm;
Tolerance for the location of conductors mm;
The conductor width value is determined by the formula:
where is the lower limit deviation of the conductor width. In this case t=1.05 mm.
The diameter of the mounting holes is calculated as follows:
where is the diameter of the outlet of the installed element; - lower limit deviation from the nominal diameter of the mounting hole; - difference between minimum hole diameter and
maximum diameter of the installed outlet.
Then d 1 =0.5 mm, d 2 =0.8 mm, d 3 =1 mm, d 2 =1.1 mm.
Let's determine the diameter of the contact pads:
where is the upper limit deviation of the hole diameter; - upper limit deviation of the conductor width.
Then D 1 =1.8 mm, D 2 =2 mm, D 3 =2.2 mm, D 2 =2.3 mm.
Let's find the value of the minimum distance between adjacent elements of the conductive pattern:
Substituting the value we get that
The calculated parameters correspond to the printed circuit board drawing. The chosen method of manufacturing a printed circuit board allows you to produce a board with the obtained parameters.
8. Calculation of reliability.
Reliability calculation consists of determining quantitative indicators reliability of the system based on the values of the reliability characteristics of the elements.
Depending on the completeness of taking into account the factors affecting the reliability of the system, an approximate reliability calculation, an approximate calculation and an updated calculation can be carried out.
An approximate calculation is carried out at the design stage, when circuit diagrams There are no system blocks yet. The number of elements in blocks is determined by comparing the designed system with similar, previously developed systems.
Reliability calculations when selecting types of elements are carried out after the development of fundamental electrical diagrams. The purpose of the calculation is to determine the rational composition of the elements.
Reliability calculations when clarifying the operating modes of elements are carried out when the main design problems have been solved, but the operating modes of the elements can still be changed.
The results of the approximate reliability calculation are presented in the form of a table.
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Name and type of elements |
Designation |
Failure rate |
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Diode bridge |
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Pulse alloy diodes |
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Double button |
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Packless capacitors |
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Ceramic capacitors |
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Film capacitors |
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Electrolytic capacitors |
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Microphone |
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Connecting wires |
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Resistors MLT-0.25 |
R2, R3, R10, R13-R15, R17 |
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Resistors MLT-1.0 |
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Resistors, unpackaged |
R1, R4, R5, R7-R9,R11, R12, R16, R18 |
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Trimmer resistor |
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LED |
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Zener diode |
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Field effect transistors |
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Bipolar transistors |
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Connector PC4TV plug |
The average time between failures is:
The reliability graph is constructed according to the exponential law
This graph is shown in Fig. 1.
Fig.1. Device reliability chart.
These results satisfy the TK condition.
9. Conclusion.
When executing course work On the topic “Acoustic relay on a field-effect transistor,” calculations were made of the design and technological parameters of the printed circuit board and the reliability of the circuit. The choice and justification of the method of manufacturing the printed circuit board and elements was made.
As a result of the work, a device was developed that fully complies with the technical specifications.
Based on the calculation results, we can conclude that the device can be produced both serially and individually without any restrictions.
List of used literature.
1. Brief reference book for the designer of radio-electronic equipment. Ed. R. G. Varlamova. M., “Sov. radio", 1973, 856 p.
2. Pavlovsky V.V., Vasilyev V.P., Gutman T.N., Design of technological processes for manufacturing REA. Guide to course design: Proc. manual for universities. - M.: Radio and communication, 1982.-160 p.
3. Development and execution of design documentation for radio-electronic equipment: Directory / E.T. Romanycheva, A.K. Ivanova, A.S. Kulikov and others; edited by THIS. Romanycheva. -2nd ed., revised. and additional - M.: Radio and Communications, 1989. - 448 p.
4. Collection of tasks and exercises on REA technology: C32 Tutorial/ Ed. E. M. Parfenova. - M.: Higher. school, 1982. - 255 p.
5. Resistors: (reference book) / Yu. N. Andreev, A. I. Antonyan, etc.; Ed. I.I. Chetvertakova. - M.: Energoizdat, 1981. - 352 p.
6. Collection of problems on reliability theory. Ed. A. M. Polovko and I. M. Malikova. M., Publishing house "Soviet Radio", 1972, 408 pp.
7. Technology and automation of radio-electronic equipment production: Textbook for universities / I.P. Bushminsky, O.Sh. Dautov, A.P. Dostanko and others; Ed. A.P. Dostanko, Sh.M. Chabdarova. - M.: Radio and Communications, 1989. - 624 p.
8. Integrated circuits: Directory / B.V. Tarabrin, L.F. Lunin and others; Ed. B.V. Tarabrina. - M.: Radio and communications. 1984 - 528 p.
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MINISTRY OF EDUCATION OF THE RUSSIAN FEDERATION Rybinsk State Aviation Technological Academy named after P.A. Solovyova |
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MODELING ELEMENTS AND UNITS OF RES |
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Academic discipline program And guidelines to implementation test work |
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For students of specialty 210201 Design and technology of electronic power systems, studying in educational programs with full and shortened training periods |
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Rybinsk 2007 |
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UDC 621.396.6
Modeling elements and RES nodes: Program of the academic discipline and guidelines for completing the test./Compiled. A.V. Pechatkin; RGATA. – Rybinsk, 2007. – 60 p. – (Correspondence course of RGATA).
COMPILER
candidate technical sciences, Associate Professor A.V. Pechatkin
DISCUSSED
at a meeting of the Department of Radioelectronic and Telecommunication Systems (RTS)
Head RIO M.A. Salkova
Computer layout – E.V. Schlein
License ID No. 06341 dated November 26, 2001
Signed for seal ________
Format 60´84 1/16 Academic edition l. 4. Circulation ____. Order _____
Copying laboratory RGATA 152934, Rybinsk, st. Pushkina, 53
ã A.V. Pechatkin, 2007
RGATA, 2007
Preface. 4
1 Basic organizational issues.. 4
2.1 General provisions. 7
2.1.1 Signal modeling. 8
2.1.2 Amplification devices. 9
3 The procedure for completing the test.. 10
3.1 Registration of the test work.. 12
3.2 Working with electronic templates and electronic documents. 13
3.2.1 Basic rules for working with electronic templates: 14
3.2.2 Registration and identification electronic documents. 14
4 Brief theoretical information. 15
4.1 Calculation of an aperiodic cascade on bipolar transistor. 15
4.1.1 Calculation of an aperiodic cascade on a field-effect transistor. 18
4.1.2 Calculation of resonant amplifiers with single and coupled oscillatory circuits. 20
Appendix A... 25
Appendix B. 26
Appendix B... 27
Appendix D. 30
Appendix D.. 32
Appendix E. 33
Appendix G.. 35
Appendix I... 36
Appendix K... 37
Appendix L.. 48
Preface
The discipline “Modeling of elements and components of electronic distribution systems” belongs to the cycle of general mathematical and natural science disciplines of specialty 210201 “Design and technology of electronic distribution systems” and is one of the disciplines aimed at mastering information technologies to support end-to-end electronic design. The discipline program set out in this manual and the requirements for completing the test are fully consistent with the State educational standard of higher professional education and the requirements for specialty 210101 “Design and technology of electrical power distribution systems”.
The textbook was developed for students of the Faculty of MRM of SibGUTI, studying the discipline “Fundamentals of computer design and modeling of electronic distribution systems”
Introduction 8
Chapter 1. Basic concepts, definitions, classification 9
1.1 Concepts of system, model and simulation 9
1.2 Classification of radio devices 10
1.3 Main types of problems in radio engineering 12
1.4 Development of the concept of model 14
1.4.2 Modeling is the most important stage of purposeful activity 15
1.4.3 Cognitive and pragmatic models 15
1.4.4 Static and dynamic models 16
1.5 Methods for implementing models 17
1.5.1 Abstract models and the role of languages 17
1.5.2 Material models and types of similarity 17
1.5.3 Conditions for implementing the properties of models 18
1.6 Correspondence between model and reality in terms of difference 19
1.6.1 Finiteness of models 19
1.6.2 Simplification of models 19
1.6.3 Approximation of models 20
1.7 Correspondence between model and reality in the aspect of similarity 21
1.7.1 Model truth 21
1.7.2 About the combination of true and false in model 21
1.7.3 Complexities of modeling algorithms 22
1.8 Main types of models 23
1.8.1 The concept of a problem situation when creating a system 23
1.8.2 Main types of formal models 24
1.8.3 Mathematical representation of the black box model 28
1.9 Relationships between modeling and design 32
1.10 Simulation accuracy 33
Chapter 2. Classification of modeling methods 37
2.1 Real simulation 37
2.2 Mental simulation 38
Chapter 3. MATHEMATICAL MODELING 40
3.1 Stages of creation mathematical models 43
H.2 Component and topological equations of the modeled object 46
3.3 Component and topological equations electrical circuit 46
Chapter 4. Features computer models 50
4.1 Computer modeling and computational experiment 51
4.2 Software tools computer modeling 52
Chapter 5. FEATURES OF THE RADIO SYSTEM AS AN OBJECT OF STUDY USING COMPUTER SIMULATION METHODS 57
5.1 Classes of radio systems 57
5.2 Formal description of radio systems 58
Chapter 6. USING THE MATHCAD APPLICATION PACKAGE FOR SIMULATING TELECOMMUNICATION DEVICES 64
6.1 Basic information about the universal mathematical software package MathCAD 64
6.2 Basics of the MathCAD 65 language
6.2.1 Input language typeMathCAD 66
6.2.2 Description of the MathCAD 67 text window
6.2.3 Input cursor 68
6.2.5 Managing interface elements 70
6.2.6 Selecting areas 71
6.2.7 Changing the document scale 71
6.2.8 Screen update 72
6.3 Basic rules for working in the MathCAD environment 79
6.3.1 Deleting mathematical expressions 79
6.3.2 Copying mathematical expressions 80
6.3.3 Transferring mathematical expressions 80
6.3.4 Entering text comments into the program 80
6.4 Plotting graphs 81
6.4.1 Plotting graphs in a Cartesian coordinate system 81
6.4.2 Plotting graphs in the polar coordinate system 83
6.4.3 Changing the graph format 85
6.4.4 Graph Tracing Rules 85
6.4.5 Rules for viewing sections of two-dimensional graphs 86
6.5 Rules for calculations in the MathCAD environment 87
6.6 Analysis of linear devices 93
6.6.1 Transfer function, transmission coefficient, time and frequency characteristics 94
6.6.2 Transfer coefficient K(jω) 95
6.6.3 Amplitude-frequency response (AFC) 96
6.6.4 Determination of transient and impulse characteristics 98
6.7 Methods for solving algebraic and transcendental equations in the MathCAD environment and organizing calculations in a cycle 101
6.7.1 Determining the roots of algebraic equations 101
6.7.2 Determining the roots of transcendental equations 103
6.7.3 Cycle calculations 106
6.8 Data processing 108
6.8.1 Piecewise linear interpolation 108
6.8.2 Spline interpolation 110
6.8.3 Extrapolation 112
6.9 Symbolic calculations 115
6.10 Optimization in REA calculations 124
6.10.1 One-dimensional optimization strategies 124
6.10.2 Local and global extremes 126
6.10.3 Methods for including uncertainty intervals 127
6.10.4 Optimization criteria 135
6.10.6 Example of writing an objective function when synthesizing filters 141
6.11 Animation of graphic material in the MathCAD environment 148
6.11.1 Preparing for animation 149
6.11.2 Example of chart animation 149
6.11.3 Calling the animation player for graphs and video files 151
6.12 Establishing a connection between MathCAD and other software environments 153
set graph algorithm iterative
The tasks of placing elements and routing their connections are closely related and are solved simultaneously with conventional, “manual” design methods. In the process of placing elements, the connection routes are refined, after which the position of some elements can be adjusted. Depending on the adopted design, technological and circuitry base, various criteria and restrictions are used when solving these problems. However, all specific varieties of the mentioned problems are associated with the problem of optimizing connection diagrams. The result is an accurate spatial arrangement of individual elements of a structural unit and geometrically a certain way connections of the terminals of these elements.
Quality criteria and constraints associated with specific placement and routing tasks are based on specific design and technological features implementation of the switching part of the node. The entire set of criteria and restrictions can be divided into two groups in accordance with the metric and topological parameters of the design of nodes and circuits.
Metric parameters include the dimensions of elements and the distances between them, the dimensions of the switching field, the distances between the terminals of the elements, permissible connection lengths, etc.
Topological parameters are mainly determined by the method adopted in a particular design for eliminating intersections of connections and the relative location of connections on the switching field. These include: the number of spatial intersections of connections, the number of interlayer transitions, the proximity of fuel elements or electromagnetically incompatible elements and connections to each other.
In specific problems, these parameters in various combinations can be either the main optimization criteria or act as constraints.
In this regard, in an algorithmic approach to solving them, they are usually considered separately. First, the elements are placed, and then the interconnects are routed. If necessary, this process can be repeated with a different arrangement of individual elements.
The main purpose of placement is to create the best conditions for subsequent routing of connections while satisfying the basic requirements that ensure the operability of the circuits.
The criterion in most cases is the criterion of minimum weighted length (MSL) of connections, which integrally takes into account the numerous requirements for the arrangement of elements and routes of their connections. This is due to a number of factors:
Reducing connection lengths improves the electrical parameters of the circuit;
The shorter the total length of the connections, the simpler, on average, is their implementation during the routing process;
Reducing the total length of connections reduces the complexity of manufacturing wiring diagrams, especially wiring diagrams;
This criterion is relatively simple from a mathematical point of view and allows you to indirectly take into account other parameters of the circuits by assigning weights to individual connections.
Questions for the exam “Modeling elements and assemblies of electronic distribution systems”
Simulation Modes.
Explain the following modeling modes in Electronic WorkBench (EWB):
6.Parameter Sweep
7. Temperature Sweep
9.Transfer Function
14. DC sweep
RES elements
1. Independent sources. Types of independent sources. Comparison of EWB and OrCAD sources.
V^@REFDES %+ %- ?DC|DC @DC| ?AC|AC @AC| ?TRAN|@TRAN|
I^@REFDES %+ %- ?DC|DC @DC| ?AC|AC @AC| ?TRAN|@TRAN|
2. Passive RLC components. Models and model parameters in CAD EWB. Mutual inductance and magnetic core.
C^@REFDES %1 %2 ?TOLERANCE|C^@REFDES| @VALUE ?IC/IC=@IC/ ?TOLERANCE|\n.model C^@REFDES CAP C=1 DEV=@TOLERANCE%|
R^@REFDES %1 %2 ?TOLERANCE|R^@REFDES| @VALUE ?TOLERANCE|\n.model R^@REFDES RES R=1 DEV=@TOLERANCE%|
L^@REFDES %1 %2 ?TOLERANCE|L^@REFDES| @VALUE ?IC/IC=@IC/ ?TOLERANCE|\n.model L^@REFDES IND L=1 DEV=@TOLERANCE%|
Kn^@REFDES L^@L1 ?L2|L^@L2| ?L3|\n+ L^@L3| ?L4|L^@L4| ?L5|\n+ L^@L5| ?L6|L^@L6| @COUPLING
Bipolar transistors
Q^@REFDES %c %b %e @MODEL
3. Scheme for measuring the dependence of the limiting frequency of current transmission fT(Ic) on the collector current ( Gain Bandwidth).
4. Scheme for measuring the dependence of the charge dissolution time ts(Ic) on the collector current ( Storage Time).
5. Scheme for measuring the dependence of the barrier capacitance of the collector-base junction Cobo(Vcb) ( C-B Capacity) and emitter-base Cibo(Veb) ( E-B Capacity).
RES nodes.
6. Aperiodic amplifier based on a bipolar transistor. Common emitter circuit. Purpose of components. Selection of the operating point on the passage (transition) and output characteristics. Purpose of elements. Providing DC mode. How to ensure linear operation of an aperiodic amplifier. Characteristics Ku, Ki, Rin, Rout. Comparison with other schemes. Amplifier equivalent circuit.
7. Negative feedback by current and voltage. Common emitter circuit with negative voltage feedback. Purpose of components. Selection of the operating point on the passage (transition) and output characteristics. Purpose of elements. Providing DC mode. How to ensure linear operation of an aperiodic amplifier. Characteristics Ku, Ki, Rin, Rout. Comparison with other schemes. Amplifier equivalent circuit.
8. Aperiodic amplifier based on a bipolar transistor. Scheme with a common base. Purpose of components. Selection of the operating point on the passage (transition) and output characteristics. Purpose of elements. Providing DC mode. How to ensure linear operation of an aperiodic amplifier. Characteristics Ku, Ki, Rin, Rout. Comparison with other schemes. Amplifier equivalent circuit.
9. Aperiodic amplifier based on a bipolar transistor. Circuit with a common collector. Purpose of components. Selection of the operating point on the passage (transition) and output characteristics. Purpose of elements. Providing DC mode. How to ensure linear operation of an aperiodic amplifier. Characteristics Ku, Ki, Rin, Rout. Comparison with other schemes. Amplifier equivalent circuit.
10. Aperiodic amplifier based on a field-effect transistor. Common source circuit. Purpose of components. Selecting the operating point on the gate and output characteristics. Purpose of elements. How to ensure linear operation of an aperiodic amplifier. Characteristics Ku, Ki, Rin, Rout. Comparison with other schemes. Amplifier equivalent circuit.
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