This document was developed under the Standard Hardware and Reliability Program (SHARP) TechnologyIndependent Representation of electronic Products (TIREP) project. It is intended for use by VHSIC HardwareDescription Language (VHDL) design engineers and is offered as guidance for the development of VHDL modelswhich are compliant with the VHDL Data Item Description (DID DI-EGDS-80811) and which can be providedto manufacturing engineering personnel for the development of production data and the subsequent productionof hardware. Most VHDL modeling performed to date has been concentrated at either the component level orat the conceptual system level. The assembly and sub-assembly levels have been largely disregarded. Under theSHARP TIREP project, an attempt has been made to help close this gap. The TIREP models are based upon lowcomplexity Standard electronic Modules (SEM) of the format A configuration. Although these modules are quitesimple, it is felt that the lessons learned offer guidance which can readily be applied to a wide range of assemblytypes and complexities.
上传时间: 2014-12-23
上传用户:xinhaoshan2016
模拟和数字电子电路基础
标签: Foundations electronic Circuits Agarwal
上传时间: 2013-11-15
上传用户:fdfadfs
Abstract: It is incredible how many programmable logic controls (PLCs) around us make our modern life possible and pleasant.Machines in our homes heat and cool our air and water, as well as preserve and cook our food. This tutorial explains the importanceof PLCs, and describes how to choose component parts using the parametric tools on the Maxim's website.A similar version of this article was published February 29, 2012 in John Day's Automotive electronic News.
上传时间: 2013-11-10
上传用户:liaocs77
Low power operation of electronic apparatus has becomeincreasingly desirable. Medical, remote data acquisition,power monitoring and other applications are good candidatesfor battery driven, low power operation. Micropoweranalog circuits for transducer-based signal conditioningpresent a special class of problems. Although micropowerICs are available, the interconnection of these devices toform a functioning micropower circuit requires care. (SeeBox Sections, “Some Guidelines for Micropower Designand an Example” and “Parasitic Effects of Test Equipmenton Micropower Circuits.”) In particular, trade-offs betweensignal levels and power dissipation become painful whenperformance in the 10-bit to 12-bit area is desirable.
上传时间: 2013-10-22
上传用户:rocketrevenge
Portable, battery-powered operation of electronic apparatushas become increasingly desirable. Medical, remotedata acquisition, power monitoring and other applicationsare good candidates for battery operation. In some circumstances,due to space, power or reliability considerations,it is preferable to operate the circuitry from a single 1.5Vcell. Unfortunately, a 1.5V supply eliminates almost alllinear ICs as design candidates. In fact, the LM10 opamp-reference and the LT®1017/LT1018 comparators arethe only IC gain blocks fully specifi ed for 1.5V operation.Further complications are presented by the 600mV dropof silicon transistors and diodes. This limitation consumesa substantial portion of available supply range, makingcircuit design diffi cult. Additionally, any circuit designedfor 1.5V operation must function at end-of-life batteryvoltage, typically 1.3V. (See Box Section, “Componentsfor 1.5V Operation.”)
标签: Circuitry Operation Single 1017
上传时间: 2013-12-20
上传用户:Wwill
EDA (electronic Design Automation)即“电子设计自动化”,是指以计算机为工作平台,以EDA软件为开发环境,以硬件描述语言为设计语言,以可编程器件PLD为实验载体(包括CPLD、FPGA、EPLD等),以集成电路芯片为目标器件的电子产品自动化设计过程。“工欲善其事,必先利其器”,因此,EDA工具在电子系统设计中所占的份量越来越高。下面就介绍一些目前较为流行的EDA工具软件。 PLD 及IC设计开发领域的EDA工具,一般至少要包含仿真器(Simulator)、综合器(Synthesizer)和配置器(Place and Routing, P&R)等几个特殊的软件包中的一个或多个,因此这一领域的EDA工具就不包括Protel、PSpice、Ewb等原理图和PCB板设计及电路仿真软件。目前流行的EDA工具软件有两种分类方法:一种是按公司类别进行分类,另一种是按功能进行划分。 若按公司类别分,大体可分两类:一类是EDA 专业软件公司,业内最著名的三家公司是Cadence、Synopsys和Mentor Graphics;另一类是PLD器件厂商为了销售其产品而开发的EDA工具,较著名的公司有Altera、Xilinx、lattice等。前者独立于半导体器件厂商,具有良好的标准化和兼容性,适合于学术研究单位使用,但系统复杂、难于掌握且价格昂贵;后者能针对自己器件的工艺特点作出优化设计,提高资源利用率,降低功耗,改善性能,比较适合产品开发单位使用。 若按功能分,大体可以分为以下三类。 (1) 集成的PLD/FPGA开发环境 由半导体公司提供,基本上可以完成从设计输入(原理图或HDL)→仿真→综合→布线→下载到器件等囊括所有PLD开发流程的所有工作。如Altera公司的MaxplusⅡ、QuartusⅡ,Xilinx公司的ISE,Lattice公司的 ispDesignExpert等。其优势是功能全集成化,可以加快动态调试,缩短开发周期;缺点是在综合和仿真环节与专业的软件相比,都不是非常优秀的。 (2) 综合类 这类软件的功能是对设计输入进行逻辑分析、综合和优化,将硬件描述语句(通常是系统级的行为描述语句)翻译成最基本的与或非门的连接关系(网表),导出给PLD/FPGA厂家的软件进行布局和布线。为了优化结果,在进行较复杂的设计时,基本上都使用这些专业的逻辑综合软件,而不采用厂家提供的集成PLD/FPGA开发工具。如Synplicity公司的Synplify、Synopsys公司的FPGAexpress、FPGA Compiler Ⅱ等。 (3) 仿真类 这类软件的功能是对设计进行模拟仿真,包括布局布线(P&R)前的“功能仿真”(也叫“前仿真”)和P&R后的包含了门延时、线延时等的“时序仿真”(也叫“后仿真”)。复杂一些的设计,一般需要使用这些专业的仿真软件。因为同样的设计输入,专业软件的仿真速度比集成环境的速度快得多。此类软件最著名的要算Model Technology公司的Modelsim,Cadence公司的NC-Verilog/NC-VHDL/NC-SIM等。 以上介绍了一些具代表性的EDA 工具软件。它们在性能上各有所长,有的综合优化能力突出,有的仿真模拟功能强,好在多数工具能相互兼容,具有互操作性。比如Altera公司的 QuartusII集成开发工具,就支持多种第三方的EDA软件,用户可以在QuartusII软件中通过设置直接调用Modelsim和 Synplify进行仿真和综合。 如果设计的硬件系统不是很大,对综合和仿真的要求不是很高,那么可以在一个集成的开发环境中完成整个设计流程。如果要进行复杂系统的设计,则常规的方法是多种EDA工具协调工作,集各家之所长来完成设计流程。
上传时间: 2013-11-19
上传用户:wxqman
Abstract: There are differences between the operation of low-frequency AC transformers and electronic transformersthat supply current to MR16 lamps, and there are also differences in the current draw for MR16 halogen lamps andMR16 LED lamps. These contrasts typically prevent an MR16 LED lamp from operating with most electronictransformers. This article explains how a high-brightness (HB) LED driver optimized for MR16 lamps will allow LEDlamps to be compatible with most electronic transformers.A similar version of this article appeared on Display Plus, July 7, 2012 and in German in Elektronikpraxis, October 1,2012.
上传时间: 2013-10-14
上传用户:playboys0
For power electronic design
上传时间: 2014-12-24
上传用户:1234321@q
Automobile electronic systems place high demands ontoday’s DC/DC converters. They must be able to preciselyregulate an output voltage in the face of wide temperatureand input voltage ranges—including load dump transientsin excess of 60V and cold crank voltage drops to 4V. Theconverter must also be able to minimize battery drain inalways-on systems by maintaining high effi ciency over abroad load current range. Similar demands are made bymany 48V nonisolated telecom applications, 40V FireWireperipherals and battery-powered applications with autoplug adaptors. The LT3437’s best in classperformancemeets all of these requirements in a small thermallyenhanced 3mm × 3mm DFN package.
上传时间: 2013-10-15
上传用户:stampede
Traditionally, an electronic Circuit Breaker (ECB) comprisesa MOSFET, a MOSFET controller and a current senseresistor. The LTC®4213 does away with the sense resistorby using the RDS(ON) of the external MOSFET. The resultis a simple, small solution that offers a signifi cant lowinsertion loss advantage at low operating load voltage.The LTC4213 features two circuit breaking responses tovarying overload conditions with three selectable tripthresholds and a high side drive for an external N-channelMOSFET switch.
上传时间: 2014-03-02
上传用户:lixinxiang