标签: sinc

AN-1265：使用ADSP-CM40XFSINC滤波器和AD7401A实现隔离式电机控制反馈

ADSP-CM403Sinc—太阳能应用中的隔离测量

ADSP-CM403Sinc—太阳能应用中的隔离测量

ADSP-CM403Sinc—太阳能应用中的隔离测量.pdf

AN-1265：使用ADSP-CM40XFSINC滤波器和AD7401A实现隔离式电机控制反馈.pdf

Thisarticleexplorestheeffectofclocktoleranceontheperformanceofthelowpassdecimationanddigitalfilterinherentinsigma-deltaADCs,andespeciallythefilternotchfrequencies.Low-bandwidthsigma-deltaapplicationscommonlytakeadvantageofthedigitalfiltertoprovide50Hz,60Hz,orsimultaneous50Hz/60Hznoiserejection.Itisimportanttounderstandtherelationshipbetweenclockfrequencyandfiltercharacteristicsofthedigitalfilterwhenchoosinganexternalclockcrystalorselectinganinternalclock.……

Foreverytimedomainwaveformthereisacorrespondingfrequencydomainwaveform,andviceversa.Forexample,arectangularpulseinthetimedomaincoincideswithasincfunction[i.e.,sin(x)/x]inthefrequencydomain.Dualityprovidesthatthereverseisalsotrue;arectangularpulseinthefrequencydomainmatchesasincfunctioninthetimedomain.WaveformsthatcorrespondtoeachotherinthismannerarecalledFouriertransformpairs.Severalcommonpairsarepresentedinthischapter.CHAPTERFourierTransformPairs11Foreverytimedomainwaveformthereisacorrespondingfrequencydomainwaveform,andviceversa.Forexample,arectangularpulseinthetimedomaincoincideswithasincfunction[i.e.,sin(x)/x]inthefrequencydomain.Dualityprovidesthatthereverseisalsotrue;arectangularpulseinthefrequencydomainmatchesasincfunctioninthetimedomain.WaveformsthatcorrespondtoeachotherinthismannerarecalledFouriertransformpairs.Severalcommonpairsarepresentedinthischapter.DeltaFunctionPairsFordiscretesignals,thedeltafunctionisasimplewaveform,andhasanequallysimpleFouriertransformpair.Figure11-1ashowsadeltafunctionin……

摘要：本文探讨了时钟公差对Σ-ΔADC中低通抽样和数字滤波器的影响，特别是对滤波器陷波频率的影响。窄带Σ-Δ应用通常利用数字滤波器提供50Hz、60Hz或50Hz/60Hz的噪声抑制。在选择外部时钟晶体或内部时钟时，了解时钟频率与数字滤波器特性之间的关系非常重要。理解高性能Σ-ΔADC中时钟公差对50Hz/60Hz噪声抑制的影响Oct02,2008摘要：本文探讨了时钟公差对Σ-ΔADC中低通抽样和数字滤波器的影响，特别是对滤波器陷波频率的影响。窄带Σ-Δ应用通常利用数字滤波器提供50Hz、60Hz或50Hz/60Hz的噪声抑制。在选择外部时钟晶体或内部时钟时，了解时钟频率与数字滤波器特性之间的关系非常重要。Σ-ΔADC利用一个调制器将模拟输入转变成一串脉冲。调制器输出端“1”与“0”脉冲之比代表模拟输入的平均值。调制器输出送入一个数字滤波器。Σ-ΔADC的数字滤波器一般用SINC(Sin(x)/x)函数的脉冲响应低通滤波器实现。该滤波器输出接至抽样电路，以降低输出码率。SINC滤波器除了滤除量化噪声这一显著功能外，也有助于提供输出码率整数倍频上的滤波器陷波。例如，60Hz输出码率需要在60Hz、120Hz、180Hz等频点陷波。将滤波器陷波调整到已知噪声源频点(例如50Hz或60Hz电力线噪声)，可以从根本上抑制噪声。使用高分辨率Σ-ΔADC测量窄带信号，在50Hz/60Hz噪声频率处有低强度信号时，该方法十分有效。输出码率和滤波器陷波频率是调制器频率、抽样频率以及滤波器阶数的函数。抽样率是调制频率与输出码率之比，而调制器频率是ADC时钟频率的函数。SINC滤波器(一般为3阶，SINC)在频域定义为：H(f)=[1/N*Sin(N*π*f/fM)/Sin(π*f/fM)]其中：N是抽样率fM是调制频率滤波器阶数和抽样率一般取决于Σ-ΔADC的设计，它们可以在模数转换器的数据手册里查到。ADC时钟频率通常由内部振荡器或外部晶体提供。图1、图……

Abstract:Digital-to-analogconverters(DACs)convertdigitaldatatoanalogvoltageorcurrentinapplicationssuchasinstrumentationandwirelesscommunications.ADAC'soutputfrequencygenerallyrangesfromDCtolessthanfS/2,wherefSistheinput-updatingfrequency.TheoutputfrequencyresponseformostDACs,however,rollsoffaccordingtothesin(x)/x(sinc)frequency-responseenvelope.Maxim>AppNotes>A/DandD/ACONVERSION/SAMPLINGCIRCUITSBASESTATIONS/WIRELESSINFRASTRUCTUREDIGITALPOTENTIOMETERSHIGH-SPEEDSIGNALPROCESSINGWIRELESS,RF,ANDCABLEKeywords:preequalization,postequalization,frequencyresponse,sinx/x,sincfunction,interpolation,Nyquist,imageJun01,2006frequency,reconstructionfilter,FIR,roll-offAPPLICATIONNOTE3853EqualizingTechniquesFlattenDACFrequencyResponseAbstract:Digital-to-analogconverters(DACs)convertdigitaldatatoanalogvoltageorcurrentinapplicationssuchasinstrumentationandwirelesscommunications.ADAC'soutputfrequencygenerallyrangesfromDCtolessthanfS/2,wherefSistheinput-updatingfrequency.TheoutputfrequencyresponseformostDACs,however,rollsoffaccordingtothesin(x……

摘要：数字-模拟转换器（DAC）将数字数据转换成模拟电压或电流的仪器和无线通信等应用。一个DAC的输出频率范围从DC到低于FS/2，其中FS是输入更新频率。然而，对于大多数的DAC输出频率响应，推出了根据SIN（X）/X（SINC）频率响应信封。Maxim>AppNotes>A/DandD/ACONVERSION/SAMPLINGCIRCUITSBASESTATIONS/WIRELESSINFRASTRUCTUREDIGITALPOTENTIOMETERSHIGH-SPEEDSIGNALPROCESSINGWIRELESS,RF,ANDCABLEKeywords:preequalization,postequalization,frequencyresponse,sinx/x,sincfunction,interpolation,Nyquist,imageJun01,2006frequency,reconstructionfilter,FIR,roll-offAPPLICATIONNOTE3853EqualizingTechniquesFlattenDACFrequencyResponseAbstract:Digital-to-analogconverters(DACs)convertdigitaldatatoanalogvoltageorcurrentinapplicationssuchasinstrumentationandwirelesscommunications.ADAC'soutputfrequencygenerallyrangesfromDCtolessthanfS/2,wherefSistheinput-updatingfrequency.TheoutputfrequencyresponseformostDACs,however,rollsoffaccordingtothesin(x……