Abstract: Transimpedance amplifiers (TIAs) are widely used to translate the current output of sensors like photodiode-to-voltagesignals, since several circuits and instruments can only accept voltage input. An operational amplifier with a feedback resistor fromoutput to the inverting input is the most straightforward implementation of such a TIA. However, even this simple TIA circuit requirescareful trade-offs among Noise gain, offset voltage, bandwidth, and stability. Clearly stability in a TIA is essential for good, reliableperformance. This application note explains the empirical calculations for assessing stability and then shows how to fine-tune theselection of the feedback phase-compensation capacitor.
標(biāo)簽: Transimpedance Stabilize Amplifier Your
上傳時(shí)間: 2013-11-13
上傳用戶:daoyue
Photodiodes can be broken into two categories: largearea photodiodes with their attendant high capacitance(30pF to 3000pF) and smaller area photodiodes withrelatively low capacitance (10pF or less). For optimalsignal-to-Noise performance, a transimpedance amplifi erconsisting of an inverting op amp and a feedback resistoris most commonly used to convert the photodiode currentinto voltage. In low Noise amplifi er design, large areaphotodiode amplifi ers require more attention to reducingop amp input voltage Noise, while small area photodiodeamplifi ers require more attention to reducing op amp inputcurrent Noise and parasitic capacitances.
上傳時(shí)間: 2013-10-28
上傳用戶:hanbeidang
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.
標(biāo)簽: 數(shù)字接收器 信號鏈 噪聲分析
上傳時(shí)間: 2014-12-05
上傳用戶:cylnpy
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.
標(biāo)簽: Converter Defi ADC 轉(zhuǎn)換器
上傳時(shí)間: 2013-11-12
上傳用戶:pans0ul
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.
標(biāo)簽: Rogers Radio John Freq
上傳時(shí)間: 2014-12-23
上傳用戶:han_zh
模擬集成電路的設(shè)計(jì)與其說是一門技術(shù),還不如說是一門藝術(shù)。它比數(shù)字集成電路設(shè)計(jì)需要更嚴(yán)格的分析和更豐富的直覺。嚴(yán)謹(jǐn)堅(jiān)實(shí)的理論無疑是嚴(yán)格分析能力的基石,而設(shè)計(jì)者的實(shí)踐經(jīng)驗(yàn)無疑是誕生豐富直覺的源泉。這也正足初學(xué)者對學(xué)習(xí)模擬集成電路設(shè)計(jì)感到困惑并難以駕馭的根本原因。.美國加州大學(xué)洛杉機(jī)分校(UCLA)Razavi教授憑借著他在美國多所著名大學(xué)執(zhí)教多年的豐富教學(xué)經(jīng)驗(yàn)和在世界知名頂級公司(AT&T,Bell Lab,HP)卓著的研究經(jīng)歷為我們提供了這本優(yōu)秀的教材。本書自2000午出版以來得到了國內(nèi)外讀者的好評和青睞,被許多國際知名大學(xué)選為教科書。同時(shí),由于原著者在世界知名頂級公司的豐富研究經(jīng)歷,使本書也非常適合作為CMOS模擬集成電路設(shè)計(jì)或相關(guān)領(lǐng)域的研究人員和工程技術(shù)人員的參考書。... 本書介紹模擬CMOS集成電路的分析與設(shè)計(jì)。從直觀和嚴(yán)密的角度闡述了各種模擬電路的基本原理和概念,同時(shí)還闡述了在SOC中模擬電路設(shè)計(jì)遇到的新問題及電路技術(shù)的新發(fā)展。本書由淺入深,理論與實(shí)際結(jié)合,提供了大量現(xiàn)代工業(yè)中的設(shè)計(jì)實(shí)例。全書共18章。前10章介紹各種基本模塊和運(yùn)放及其頻率響應(yīng)和噪聲。第11章至第13章介紹帶隙基準(zhǔn)、開關(guān)電容電路以及電路的非線性和失配的影響,第14、15章介紹振蕩器和鎖相環(huán)。第16章至18章介紹MOS器件的高階效應(yīng)及其模型、CMOS制造工藝和混合信號電路的版圖與封裝。 1 Introduction to Analog Design 2 Basic MOS Device Physics 3 Single-Stage Amplifiers 4 Differential Amplifiers 5 Passive and Active Current Mirrors 6 Frequency Response of Amplifiers 7 Noise 8 Feedback 9 Operational Amplifiers 10 Stability and Frequency Compensation 11 Bandgap References 12 Introduction to Switched-Capacitor Circuits 13 Nonlinearity and Mismatch 14 Oscillators 15 Phase-Locked Loops 16 Short-Channel Effects and Device Models 17 CMOS Processing Technology 18 Layout and Packaging
標(biāo)簽: analog design cmos of
上傳時(shí)間: 2014-12-23
上傳用戶:杜瑩12345
印刷電路板(PCB)設(shè)計(jì)解決方案市場和技術(shù)領(lǐng)軍企業(yè)Mentor Graphics(Mentor Graphics)宣布推出HyperLynx® PI(電源完整性)產(chǎn)品,滿足業(yè)內(nèi)高端設(shè)計(jì)者對于高性能電子產(chǎn)品的需求。HyperLynx PI產(chǎn)品不僅提供簡單易學(xué)、操作便捷,又精確的分析,讓團(tuán)隊(duì)成員能夠設(shè)計(jì)可行的電源供應(yīng)系統(tǒng);同時(shí)縮短設(shè)計(jì)周期,減少原型生成、重復(fù)制造,也相應(yīng)降低產(chǎn)品成本。隨著當(dāng)今各種高性能/高密度/高腳數(shù)集成電路的出現(xiàn),傳輸系統(tǒng)的設(shè)計(jì)越來越需要工程師與布局設(shè)計(jì)人員的緊密合作,以確保能夠透過眾多PCB電源與接地結(jié)構(gòu),為IC提供純凈、充足的電力。配合先前推出的HyperLynx信號完整性(SI)分析和確認(rèn)產(chǎn)品組件,Mentor Graphics目前為用戶提供的高性能電子產(chǎn)品設(shè)計(jì)堪稱業(yè)內(nèi)最全面最具實(shí)用性的解決方案。“我們擁有非常高端的用戶,受到高性能集成電路多重電壓等級和電源要求的驅(qū)使,需要在一個(gè)單一的PCB中設(shè)計(jì)30余套電力供應(yīng)結(jié)構(gòu)。”Mentor Graphics副總裁兼系統(tǒng)設(shè)計(jì)事業(yè)部總經(jīng)理Henry Potts表示。“上述結(jié)構(gòu)的設(shè)計(jì)需要快速而準(zhǔn) 確的直流壓降(DC Power Drop)和電源雜訊(Power Noise)分析。擁有了精確的分析信息,電源與接地層結(jié)構(gòu)和解藕電容數(shù)(de-coupling capacitor number)以及位置都可以決定,得以避免過于保守的設(shè)計(jì)和高昂的產(chǎn)品成本。”
上傳時(shí)間: 2013-11-18
上傳用戶:362279997
隨著系統(tǒng)設(shè)計(jì)復(fù)雜性和集成度的大規(guī)模提高,電子系統(tǒng)設(shè)計(jì)師們正在從事100MHZ以上的電路設(shè)計(jì),總線的工作頻率也已經(jīng)達(dá)到或者超過50MHZ,有一大部分甚至超過100MHZ。目前約80% 的設(shè)計(jì)的時(shí)鐘頻率超過50MHz,將近50% 以上的設(shè)計(jì)主頻超過120MHz,有20%甚至超過500M。當(dāng)系統(tǒng)工作在50MHz時(shí),將產(chǎn)生傳輸線效應(yīng)和信號的完整性問題;而當(dāng)系統(tǒng)時(shí)鐘達(dá)到120MHz時(shí),除非使用高速電路設(shè)計(jì)知識,否則基于傳統(tǒng)方法設(shè)計(jì)的PCB將無法工作。因此,高速電路信號質(zhì)量仿真已經(jīng)成為電子系統(tǒng)設(shè)計(jì)師必須采取的設(shè)計(jì)手段。只有通過高速電路仿真和先進(jìn)的物理設(shè)計(jì)軟件,才能實(shí)現(xiàn)設(shè)計(jì)過程的可控性。傳輸線效應(yīng)基于上述定義的傳輸線模型,歸納起來,傳輸線會對整個(gè)電路設(shè)計(jì)帶來以下效應(yīng)。 · 反射信號Reflected signals · 延時(shí)和時(shí)序錯(cuò)誤Delay & Timing errors · 過沖(上沖/下沖)Overshoot/Undershoot · 串?dāng)_Induced Noise (or crosstalk) · 電磁輻射EMI radiation
標(biāo)簽: 高速電路 傳輸線 效應(yīng)分析
上傳時(shí)間: 2013-11-16
上傳用戶:lx9076
數(shù)字與模擬電路設(shè)計(jì)技巧IC與LSI的功能大幅提升使得高壓電路與電力電路除外,幾乎所有的電路都是由半導(dǎo)體組件所構(gòu)成,雖然半導(dǎo)體組件高速、高頻化時(shí)會有EMI的困擾,不過為了充分發(fā)揮半導(dǎo)體組件應(yīng)有的性能,電路板設(shè)計(jì)與封裝技術(shù)仍具有決定性的影響。 模擬與數(shù)字技術(shù)的融合由于IC與LSI半導(dǎo)體本身的高速化,同時(shí)為了使機(jī)器達(dá)到正常動(dòng)作的目的,因此技術(shù)上的跨越競爭越來越激烈。雖然構(gòu)成系統(tǒng)的電路未必有clock設(shè)計(jì),但是毫無疑問的是系統(tǒng)的可靠度是建立在電子組件的選用、封裝技術(shù)、電路設(shè)計(jì)與成本,以及如何防止噪訊的產(chǎn)生與噪訊外漏等綜合考慮。機(jī)器小型化、高速化、多功能化使得低頻/高頻、大功率信號/小功率信號、高輸出阻抗/低輸出阻抗、大電流/小電流、模擬/數(shù)字電路,經(jīng)常出現(xiàn)在同一個(gè)高封裝密度電路板,設(shè)計(jì)者身處如此的環(huán)境必需面對前所未有的設(shè)計(jì)思維挑戰(zhàn),例如高穩(wěn)定性電路與吵雜(noisy)性電路為鄰時(shí),如果未將噪訊入侵高穩(wěn)定性電路的對策視為設(shè)計(jì)重點(diǎn),事后反復(fù)的設(shè)計(jì)變更往往成為無解的夢魘。模擬電路與高速數(shù)字電路混合設(shè)計(jì)也是如此,假設(shè)微小模擬信號增幅后再將full scale 5V的模擬信號,利用10bit A/D轉(zhuǎn)換器轉(zhuǎn)換成數(shù)字信號,由于分割幅寬祇有4.9mV,因此要正確讀取該電壓level并非易事,結(jié)果造成10bit以上的A/D轉(zhuǎn)換器面臨無法順利運(yùn)作的窘境。另一典型實(shí)例是使用示波器量測某數(shù)字電路基板兩點(diǎn)相隔10cm的ground電位,理論上ground電位應(yīng)該是零,然而實(shí)際上卻可觀測到4.9mV數(shù)倍甚至數(shù)十倍的脈沖噪訊(pulse Noise),如果該電位差是由模擬與數(shù)字混合電路的grand所造成的話,要測得4.9 mV的信號根本是不可能的事情,也就是說為了使模擬與數(shù)字混合電路順利動(dòng)作,必需在封裝與電路設(shè)計(jì)有相對的對策,尤其是數(shù)字電路switching時(shí),ground vance Noise不會入侵analogue ground的防護(hù)對策,同時(shí)還需充分檢討各電路產(chǎn)生的電流回路(route)與電流大小,依此結(jié)果排除各種可能的干擾因素。以上介紹的實(shí)例都是設(shè)計(jì)模擬與數(shù)字混合電路時(shí)經(jīng)常遇到的瓶頸,如果是設(shè)計(jì)12bit以上A/D轉(zhuǎn)換器時(shí),它的困難度會更加復(fù)雜。
標(biāo)簽: 數(shù)字 模擬電路 設(shè)計(jì)技巧
上傳時(shí)間: 2013-11-16
上傳用戶:731140412
Integrated EMI/Thermal Design forSwitching Power SuppliesWei ZhangThesis submitted to the Faculty of theVirginia Polytechnic Institute and State Universityin partial fulfillment of the requirements for the degree of Integrated EMI/Thermal Design forSwitching Power SuppliesWei Zhang(ABSTRACT)This work presents the modeling and analysis of EMI and thermal performancefor switch power supply by using the CAD tools. The methodology and design guidelinesare developed.By using a boost PFC circuit as an example, an equivalent circuit model is builtfor EMI Noise prediction and analysis. The parasitic elements of circuit layout andcomponents are extracted analytically or by using CAD tools. Based on the model, circuitlayout and magnetic component design are modified to minimize circuit EMI. EMI filtercan be designed at an early stage without prototype implementation.In the second part, thermal analyses are conducted for the circuit by using thesoftware Flotherm, which includes the mechanism of conduction, convection andradiation. Thermal models are built for the components. Thermal performance of thecircuit and the temperature profile of components are predicted. Improved thermalmanagement and winding arrangement are investigated to reduce temperature.In the third part, several circuit layouts and inductor design examples are checkedfrom both the EMI and thermal point of view. Insightful information is obtained.
標(biāo)簽: EMI 開關(guān)電源 英文
上傳時(shí)間: 2013-11-10
上傳用戶:1595690
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