以某高速实时频谱仪为应用背景，论述了5 Gsps采样率的高速数据采集系统的构成和设计要点，着重分析了采集系统的关键部分高速ADC（analog to digital，模数转换器）的设计、系统采样时钟设计、模数混合信号完整性设计、电磁兼容性设计和基于总线和接口标准（PCI Express）的数据传输和处理软件设计。在实现了系统硬件的基础上，采用Xilinx公司ISE软件的在线逻辑分析仪（ChipScope Pro）测试了ADC和采样时钟的性能，实测表明整体指标达到设计要求。给出上位机对采集数据进行处理的结果，表明系统实现了数据的实时采集存储功能。
上传时间： 2014-11-26
上传用户：黄蛋的蛋黄
Digital-to-analog converters (DACs) are prevalent inindustrial control and automated test applications.General-purpose automated test equipment often requiresmany channels of precisely controlled voltagesthat span several voltage ranges. The LTC2704 is ahighly integrated 16-bit, 4-channel DAC for high-endapplications. It has a wide range of features designed toincrease performance and simplify design.
上传时间： 2013-11-22
上传用户：元宵汉堡包
Designers of signal receiver systems often need to performcascaded chain analysis of system performancefrom the antenna all the way to the ADC. Noise is a criticalparameter in the chain analysis because it limits theoverall sensitivity of the receiver. An application’s noiserequirement has a signifi cant infl uence on the systemtopology, since the choice of topology strives to optimizethe overall signal-to-noise ratio, dynamic range andseveral other parameters. One problem in noise calculationsis translating between the various units used by thecomponents in the chain: namely the RF, IF/baseband,and digital (ADC) sections of the circuit.
上传时间： 2014-12-05
上传用户：cylnpy
Control systems are becoming increasingly dependent on digital processing and so require sensors able to provide direct digital inputs. Sensors based on time measurement, having outputs based on a frequency or phase, have an advantage over conventional analogue sensors in that their outputs can be measured directly in digital systems by pulse counting.
上传时间： 2013-10-08
上传用户：wuyuying
The LM20, LM45, LM50, LM60, LM61, and LM62 are analog output temperature sensors. They have various output voltage slopes (6.25mV/°C to 17mV/°C) and power supply voltage ranges (2.4V to 10V).The LM20 is the smallest, lowest power consumption analog output temperature sensor National Semiconductor has released. The LM70 and LM74 are MICROWIRE/SPI compatible digital temperature sensors. The LM70 has a resolution of 0.125°C while the LM74 has a resolution of 0.625°C. The LM74 is the most accurate of the two with an accuracy better than ±1.25°C. The LM75 is National’s first digital output temperature sensor, released several years ago.
上传时间： 2014-12-23
上传用户：yl8908
Differential Nonlinearity: Ideally, any two adjacent digitalcodes correspond to output analog voltages that are exactlyone LSB apart. Differential non-linearity is a measure of theworst case deviation from the ideal 1 LSB step. For example,a DAC with a 1.5 LSB output change for a 1 LSB digital codechange exhibits 1⁄2 LSB differential non-linearity. Differentialnon-linearity may be expressed in fractional bits or as a percentageof full scale. A differential non-linearity greater than1 LSB will lead to a non-monotonic transfer function in aDAC.Gain Error (Full Scale Error): The difference between theoutput voltage (or current) with full scale input code and theideal voltage (or current) that should exist with a full scale inputcode.Gain Temperature Coefficient (Full Scale TemperatureCoefficient): Change in gain error divided by change in temperature.Usually expressed in parts per million per degreeCelsius (ppm/°C).Integral Nonlinearity (Linearity Error): Worst case deviationfrom the line between the endpoints (zero and full scale).Can be expressed as a percentage of full scale or in fractionof an LSB.LSB (Lease-Significant Bit): In a binary coded system thisis the bit that carries the smallest value or weight. Its value isthe full scale voltage (or current) divided by 2n, where n is theresolution of the converter.Monotonicity: A monotonic function has a slope whose signdoes not change. A monotonic DAC has an output thatchanges in the same direction (or remains constant) for eachincrease in the input code. the converse is true for decreasing codes.
标签： Converters Defini DAC
上传时间： 2013-10-30
上传用户：stvnash
ANALOG INPUT BANDWIDTH is a measure of the frequencyat which the reconstructed output fundamental drops3 dB below its low frequency value for a full scale input. Thetest is performed with fIN equal to 100 kHz plus integer multiplesof fCLK. The input frequency at which the output is −3dB relative to the low frequency input signal is the full powerbandwidth.APERTURE JITTER is the variation in aperture delay fromsample to sample. Aperture jitter shows up as input noise.APERTURE DELAY See Sampling Delay.BOTTOM OFFSET is the difference between the input voltagethat just causes the output code to transition to the firstcode and the negative reference voltage. Bottom Offset isdefined as EOB = VZT–VRB, where VZT is the first code transitioninput voltage and VRB is the lower reference voltage.Note that this is different from the normal Zero Scale Error.CONVERSION LATENCY See PIPELINE DELAY.CONVERSION TIME is the time required for a completemeasurement by an analog-to-digital converter. Since theConversion Time does not include acquisition time, multiplexerset up time, or other elements of a complete conversioncycle, the conversion time may be less than theThroughput Time.DC COMMON-MODE ERROR is a specification which appliesto ADCs with differential inputs. It is the change in theoutput code that occurs when the analog voltages on the twoinputs are changed by an equal amount. It is usually expressed in LSBs.
上传时间： 2013-11-12
上传用户：pans0ul
前面讨论了很多内容，基本上涉及了有关PCB板的绝大部分相关的知识。第二章探讨了传输线的基本原理，第三章探讨了串扰，在第四章里我们阐述了许多在现代设计中必须关注的非理想互连的问题。对于信号从驱动端引脚到接收端引脚的电气路径的相关问题，我们已经做了一些探究，然而对于硅芯片，即处于封装内部的IC来说，其信号传输通常要通过过孔和连接器来进行，对这样的情况我们该如何处理？在本章中，我们将通过对封装、过孔和连接器的研究，阐述其原理，从而指导大家在设计的时候对整个电气路径进行完整地分析，即从驱动端内部IC芯片的焊盘到接受器IC芯片的焊盘。
标签： High-Speed Digital System desi
上传时间： 2013-11-24
上传用户：maizezhen
高速数字系统设计下载pdf:High-Speed Digital SystemDesign—A Handbook ofInterconnect Theory and DesignPracticesStephen H. HallGarrett W. HallJames A. McCallA Wiley-Interscience Publication JOHN WILEY & SONS, INC.New York • Chichester • Weinheim • Brisbane • Singapore • TorontoCopyright © 2000 by John Wiley & Sons, Inc.speeddigital systems at the platform level. The book walks the reader through everyrequired concept, from basic transmission line theory to digital timing analysis, high-speedmeasurement techniques, as well as many other topics. In doing so, a unique balancebetween theory and practical applications is achieved that will allow the reader not only tounderstand the nature of the problem, but also provide practical guidance to the solution.The level of theoretical understanding is such that the reader will be equipped to see beyondthe immediate practical application and solve problems not contained within these pages.Much of the information in this book has not been needed in past digital designs but isabsolutely necessary today. Most of the information covered here is not covered in standardcollege curricula, at least not in its focus on digital design, which is arguably one of the mostsignificant industries in electrical engineering.The focus of this book is on the design of robust high-volume, high-speed digital productssuch as computer systems, with particular attention paid to computer busses. However, thetheory presented is applicable to any high-speed digital system. All of the techniquescovered in this book have been applied in industry to actual digital products that have beensuccessfully produced and sold in high volume.Practicing engineers and graduate and undergraduate students who have completed basicelectromagnetic or microwave design classes are equipped to fully comprehend the theorypresented in this book. At a practical level, however, basic circuit theory is all thebackground required to apply the formulas in this book.
上传时间： 2013-10-26
上传用户：缥缈
Finite state machines are widely used in digital circuit designs. Generally, when designing a state machine using an HDL, the synthesis tools will optimize away all states that cannot be reached and generate a highly optimized circuit. Sometimes, however, the optimization is not acceptable. For example, if the circuit powers up in an invalid state, or the circuit is in an extreme working environment and a glitch sends it into an undesired state, the circuit may never get back to its normal operating condition.
标签： Creating Machines Mentor State
上传时间： 2013-10-08
上传用户：wangzhen1990
