通過比較各種隔離數(shù)字通信的特點和應(yīng)用范圍，指出塑料光纖在隔離數(shù)字通信中的優(yōu)勢。使用已經(jīng)標(biāo)準(zhǔn)化的TOSLINK接口，有利于節(jié)省硬件開發(fā)成本和簡化設(shè)計難度。給出了塑料光纖的硬件驅(qū)動電路，說明設(shè)計過程中的注意事項，對光收發(fā)模塊的電壓特性和頻率特性進(jìn)行全面試驗，并給出SPI口使用塑料光纖隔離通信的典型應(yīng)用電路圖。試驗結(jié)果表明，該設(shè)計可為電力現(xiàn)場、電力電子及儀器儀表的設(shè)計提供參考。
Abstract:
y comparing characteristics and applications area of various isolated digital communications， this article indicates advantages of plastic optical fiber in isolated digital communications. Using the standardized TOSLINK interface， it helps to control costs and difficulty in hardware development and design. Then it gives the hardware driver circuit of plastic optical fiber module， explains the noticed details in design process， gives results on the basis of the optical transceiver module voltage characteristics and frequency characteristics tests. Finally，it gives typical application circuit of the SPI communication port by using plastic optical fiber isolation .The results show that this design can be referenced for the power field， power electronics and instrumentation design.
Single-Ended and Differential S-Parameters
Differential circuits have been important incommunication systems for many years. In the past,differential communication circuits operated at lowfrequencies, where they could be designed andanalyzed using lumped-element models andtechniques. With the frequency of operationincreasing beyond 1GHz, and above 1Gbps fordigital communications, this lumped-elementapproach is no longer valid, because the physicalsize of the circuit approaches the size of awavelength.Distributed models and analysis techniques are nowused instead of lumped-element techniques.Scattering parameters, or S-parameters, have beendeveloped for this purpose [1]. These S-parametersare defined for single-ended networks. S-parameterscan be used to describe differential networks, but astrict definition was not developed until Bockelmanand others addressed this issue [2]. Bockelman’swork also included a study on how to adapt single-ended S-parameters for use with differential circuits[2]. This adaptation, called “mixed-mode S-parameters,” addresses differential and common-mode operation, as well as the conversion betweenthe two modes of operation.This application note will explain the use of single-ended and mixed-mode S-parameters, and the basicconcepts of microwave measurement calibration.
Agilent AN 154 S-Parameter Design Application Note S參數(shù)的設(shè)計與應(yīng)用
The need for new high-frequency, solid-state circuitdesign techniques has been recognized both by microwaveengineers and circuit designers. These engineersare being asked to design solid state circuitsthat will operate at higher and higher frequencies.The development of microwave transistors andAgilent Technologies’ network analysis instrumentationsystems that permit complete network characterizationin the microwave frequency rangehave greatly assisted these engineers in their work.The Agilent Microwave Division’s lab staff hasdeveloped a high frequency circuit design seminarto assist their counterparts in R&D labs throughoutthe world. This seminar has been presentedin a number of locations in the United States andEurope.From the experience gained in presenting this originalseminar, we have developed a four-part videotape, S-Parameter Design Seminar. While the technologyof high frequency circuit design is everchanging, the concepts upon which this technologyhas been built are relatively invariant.The content of the S-Parameter Design Seminar isas follows:
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ExpressPCB 是一款免費的PCB設(shè)計軟件，簡單實使。可以畫雙層板。
Our Free PCB software is a snap to learn and use. For the first time, designing circuit boards is simple for the beginner and efficient for the professional.
Our board manufacturing service makes top quality two and four layer PCBs. Use our MiniBoard service and pay only $51 for three boards (plus $8 shipping).
Abstract: Using a wafer-level package (WLP) can reduce the overall size and cost of your solution.However when using a WLP IC, the printed circuit board (PCB) layout can become more complex and, ifnot carefully planned, result in an unreliable design. This article presents some PCB designconsiderations and general recommendations for choosing a 0.4mm- or 0.5mm-pitch WLP for yourapplication.
This Application Note covers the basics of how to use Verilog as applied to ComplexProgrammable Logic Devices. Various combinational logic circuit examples, such asmultiplexers, decoders, encoders, comparators and adders are provided. Synchronous logiccircuit examples, such as counters and state machines are also provided.
