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A Design Of Constant Current Source System On Semiconductor Material Resistivity Measurement

Posted on:2010-10-12Degree:MasterType:Thesis
Country:ChinaCandidate:F YangFull Text:PDF
GTID:2178360275997626Subject:Microelectronics and Solid State Electronics
Abstract/Summary:PDF Full Text Request
With the new materials research and development, on the material resistivity measurement become increasingly important, the current domestic microelectronics industry, such as the use of linear array spacing as the four-probe measurement of room temperature resistivity Materials method, applied four probe method Resistivity measurement has attracted attention. Four-probe measurement system is the advantages of simple equipment easy to operate, high precision, the shape of the sample without strict requirements. Is a constant current source to provide constant current load circuit, it is the four-probe resistivity test system, regardless of an important component, it can be said of the performance at constant current source to a large extent determines the four-probe test performance of the system.Constant current source circuit is often used to describe the size of an output current with external influences unrelated to electronic circuits. In fact, when the circuit external conditions Change a certain scope to provide load current essentially unchanged. It has been widely used in semiconductor material parameters of measuring instruments, education, scientific research and actual production of. Resistivity conductive semiconductor materials are reflected in the performance of one of the important parameters. Measuring the resistivity of a lot of Ways, four-probe method is a widely used standard method. Its advantage is easy to operate simple equipment, high accuracy, the shape of the sample without the stringent requirements, while the four-probe tester as an important component of constant current source circuit is particularly important.This article from the constant current source has the basic concept of the constant current source applications and statements were made more detailed introduction and analysis; then introduce DC power supply the basic concepts, basic components; Next, on the constant current source a more detailed description of one of several constant-current source circuit analysis; then introduce the four-probe tester and with the self-designed constant-current source circuit using LM317 three-terminal adjustable voltage regulator integrated as a stable pressure part of the core, by the improved transistor constant current source circuit as a constant part of the core, and used to carry out TIP122 Darlington pipe expansion flow, and then carried out on the circuit simulation software, testing, meet the stipulated requirements; Finally, the use of Protel99SE put circuit made of printed circuit board software, and good circuit board assembly testing and adjustments. Finally, sum up the full text points out the shortcomings and some of their own experience, and give further research directions.
Keywords/Search Tags:Four-Probe, Constant Current source, Potentiometers, Regulator
PDF Full Text Request
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