24 jan. Eletrônica Analógica Aula Teste: Instrumentos de medição eletro-eletrônicos. Professor: Ivanildo Antonio da Silva Junior Introdução Eletrônica. Veja grátis o arquivo Eletrônica Analógica enviado para a disciplina de Física II Categoria: Trabalhos – 28 – Veja grátis o arquivo Eletrônica Analógica enviado para a disciplina de Física II Categoria: Trabalhos – 4 –
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The characteristics of an ideal diode are those of a switch that can conduct current in only one direction. In metric units,the resistivity of a material is measured in -cm or -m.
Eletronica analogica Apostila sobre eletronica analogica 1. It is the simplest of semiconductor devices but plays a very vital role in electronic systems,having characteristics that closely match those of a simple switch.
Ideally,a diode will conduct current in the direction defined by the arrow in the symbol and act dletronica an open circuit to any attempt to establish current in the opposite direction.
The ideal diodeis a two-terminaldevice having the symbol and characteristics shown in Figs. Consider the region of negatively applied potential third eltronica of Fig.
The miniaturization that has resulted leaves us to wonder about its limits. It refers to any device or system that has ideal characteristics—perfect in every way.
If the resulting current has the opposite direction,as shown in Fig. As indicated earlier,the primary purpose of this section is to introduce the characteristics of an ideal device for comparison with the characteristics of the commercial variety. Miniaturization appears to be limited by three factors each of which will be addressed in this text: Complete systems now appear on wafers thousands of times smaller than the single element of earlier networks.
The prefix semiis normally applied to a range of levels midway between two limits. Although you may be familiar with the electrical properties of copper and. This fact will be helpful to remember as we compare resistivity levels in the discussions to follow.
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A semiconductor, therefore, is a material that has a conductivity level somewhere between the extremes of an insulator and a conductor. An insulator is a material that offers a naalogica low level of conductivity under pressure from an applied voltage source. For those of us who experienced the change from glass envelope tubes to the solid-state era,it still seems like a few short years ago. In tables,the term resistivity ,Greek letter rho is often used when comparing the resistance levels of materials.
In fact,if the area of Fig. One of the important parameters for the diode is the resistance at the point or re- gion of operation. It is now some analogicw years since the first transistor was introduced on December 23, In addition to the details of its construction and characteristics,the very important data and graphs to be found on specification sheets will also be covered to ensure an annalogica of the terminology employed and to demonstrate the wealth of information typically available from manufacturers.
Parte rletronica de 6. The units of -cm are derived from the substitution of the units for each quantity of Fig. If the current through the diode has the direction indicated in Fig. If the polarity of the applied voltage is consistent with that shown in Fig.
We have also reached a point at which the primary purpose of the container is simply to provide some means of handling the device or system and to provide a mechanism for attachment to the remainder of the network. The engineer becomes more and more limited in his or her knowledge of the broad range of advances— it is difficult enough simply to stay abreast of the changes in one area of research or development. They are,however,the two materials that have received the broadest range of interest in the development of semiconductor devices.
Conductor Semiconductor Insulator mica from your past studies,the characteristics of the semiconductor materials of germanium Ge and silicon Si may be relatively new. The term conductor is applied to any material that will support a generous flow of charge when a voltage source of limited magnitude is applied across its terminals.
The first edition of this text contained heavy coverage of tubes,with succeeding editions involving the important decision of how much coverage should be dedicated to tubes and how much to semiconductor devices.
As we progress through the next few sections,keep the following questions in mind:. Inversely related to the conductivity of a material is its resistance to the flow of charge,or current. Our sincerest appreciation must be extended to the instructors who have used the text and sent in comments, corrections, and suggestions. In the description of the elements to follow,it is critical that the various letter symbols,voltage polarities,and current directionsbe defined.