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
The 14-bit LTC2351-14 is a 1.5Msps, low power SARADC with six simultaneously sampled differential inputchannels. It operates from a single 3V supply and featuressix independent sample-and-hold amplifi ers and a singleADC. The single ADC with multiple S/HAs enables excellentrange match (1mV) Between channels and channel-tochannelskew (200ps).
上传时间： 2014-12-23
上传用户：天诚24
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
分析了调幅信号和载波信号之间的相位差与调制信号的极性的对应关系,得出了相敏检波电路输出电压的极性与调制信号的极性有对应关系的结论。为了验证相敏检波电路的这一特性,给出3 个电路方案,分别选用理想元件和实际元件,采用Multisim 对其进行仿真实验,直观形象地演示了相敏检波电路的鉴相特性,是传统的实际操作实验所不可比拟的。关键词:相敏检波;鉴相特性;Multisim;电路仿真 Abstract : The corresponding relation Between modulation signal polarity and difference phases of amplitudemodulated signal and the carrier signal ,the polarity of phase2sensitive detecting circuit output voltage and the polarity of modulation signal are correspondent . In order to verify this characteristic ,three elect ric circuit s plans are produced ,idea element s and actual element s are selected respectively. Using Multisim to carry on a simulation experiment ,and then demonst rating the phase detecting characteristic of the phase sensitive circuit vividly and directly. Which is t raditional practical experience cannot be com pared.Keywords :phase sensitive detection ;phase2detecting characteristic ;Multisim;circuit simulation
上传时间： 2013-11-23
上传用户：guanhuihong
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
Radio Frequency Integrated Circuit Design I enjoyed reading this book for a number of reasons. One reason is that itaddresses high-speed analog design in the context of microwave issues. This isan advanced-level book, which should follow courses in basic circuits andtransmission lines. Most analog integrated circuit designers in the past workedon applications at low enough frequency that microwave issues did not arise.As a consequence, they were adept at lumped parameter circuits and often notcomfortable with circuits where waves travel in space. However, in order todesign radio frequency (RF) communications integrated circuits (IC) in thegigahertz range, one must deal with transmission lines at chip interfaces andwhere interconnections on chip are far apart. Also, impedance matching isaddressed, which is a topic that arises most often in microwave circuits. In mycareer, there has been a gap in comprehension Between analog low-frequencydesigners and microwave designers. Often, similar issues were dealt with in twodifferent languages. Although this book is more firmly based in lumped-elementanalog circuit design, it is nice to see that microwave knowledge is brought inwhere necessary.Too many analog circuit books in the past have concentrated first on thecircuit side rather than on basic theory behind their application in communications.The circuits usually used have evolved through experience, without asatisfying intellectual theme in describing them. Why a given circuit works bestcan be subtle, and often these circuits are chosen only through experience. Forthis reason, I am happy that the book begins first with topics that require anintellectual approach—noise, linearity and filtering, and technology issues. Iam particularly happy with how linearity is introduced (power series). In therest of the book it is then shown, with specific circuits and numerical examples,how linearity and noise issues arise.
上传时间： 2014-12-23
上传用户：han_zh
Calculation of the Differential Impedance of Tracks on FR4 substrates There is a discrepancy Between calculated and measured values of impedance for differential transmission lineson FR4. This is especially noticeable in the case of surface microstrip configurations. The anomaly is shown tobe due to the nature of the substrate material. This needs to be considered as a layered structure of epoxy resinand glass fibre. Calculations, using Boundary Element field methods, show that the distribution of the electricfield within this layered structure determines the apparent dielectric constant and therefore affects theimpedance. Thus FR4 cannot be considered to be uniform dielectric when calculating differential impedance.
上传时间： 2014-12-24
上传用户：DE2542
This document provides practical, common guidelines for incorporating PCI Express interconnect layouts onto Printed Circuit Boards (PCB) ranging from 4-layer desktop baseboard designs to 10- layer or more server baseboard designs. Guidelines and constraints in this document are intended for use on both baseboard and add-in card PCB designs. This includes interconnects Between PCI Express devices located on the same baseboard (chip-to-chip routing) and interconnects Between a PCI Express device located “down” on the baseboard and a device located “up” on an add-in card attached through a connector. This document is intended to cover all major components of the physical interconnect including design guidelines for the PCB traces, vias and AC coupling capacitors, as well as add-in card edge-finger and connector considerations. The intent of the guidelines and examples is to help ensure that good high-speed signal design practices are used and that the timing/jitter and loss/attenuation budgets can also be met from end-to-end across the PCI Express interconnect. However, while general physical guidelines and suggestions are given, they may not necessarily guarantee adequate performance of the interconnect for all layouts and implementations. Therefore, designers should consider modeling and simulation of the interconnect in order to ensure compliance to all applicable specifications. The document is composed of two main sections. The first section provides an overview of general topology and interconnect guidelines. The second section concentrates on physical layout constraints where bulleted items at the beginning of a topic highlight important constraints, while the narrative that follows offers additional insight.
上传时间： 2013-10-15
上传用户：busterman
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
