QC活动培训2(工具篇)

工业应用Sigma-DeltaADC常见问题解答编写人CAST(M)版本号2.02007-8-14------------------------------------------------------------------------------------------------------------本报告为AnalogDevicesInc.(ADI)中国技术支持中心专用，ADI可以随时修改本报告而不用通知任何使用本报告的人员。如有任何问题请与[e-mail]联系。------------------------------------------------------------------------------------------------------------目录1简介...........................................................................................................................................11.1产品简介...................................................................................................................11.2参考资料...................................................................................................................22Sigma-DeltaADC原理简介.....................................................................................................43常见应用问题解答...................................................................................................................63.1峰峰值噪声与有效噪声的区别，峰峰值分辨率与有效分辨率的区别？无失码分辨率又是指的什么？...............................................................................................................63.2为什么转换结果的后几位总在跳，是不是正常？...............................................63.3在使用多通道SIGMA-DELTAADC时，通道切换的速度很慢？........................73.4什么情况下要使用内部的BUFFER？....................................................................73.5怎样使用50/60Hz抗工频干扰功能？....................................................................73.6我的信号是双极性的信号，能不能直接输入到单电源供电的ADC？...............83.7什么是CHOP模式，它有什么作用？....................................................................83.8什么是单端信号，什么是全差分，什么是伪差分？...........................................83.9ADI的SIGMA-DELTAADC的输出码的格式是什么？........................................93.10怎样选择SIGMA-DELTAADC的参考源？.........................................................103.11用串口配置芯片让其转换，但是/DRDY一直为高，芯片不转换？.................103.12为什么SPI口在正常工作了一段时间后就被锁住了，/DRDY一直为高，读出的值也都全为1？......................................................................................................................103.13什么情况下做自校准，什么情况下做系统校准？.............................................103.14在PCB布局布线时，应注意些什么？.................................................................113.15是否能够提供评估板和例子程序？.....................................................................113.16是否能够申请免费样片？.....................................................................................123.17多通道Sigma-DeltaADC产品.............................................................................121ASigma-DeltaADC常见问题解答中国技术支持中心电话：800-810-1742传真：800-810-1747Email：[e-mail]11简介1.1产品简介ADI拥有一系列种类齐全的高分辨率低带宽的Sigma-DeltaADC产品，这些产品不仅集成了ADC，还集成了电流源、多路开关、可编程增益放大器PGA，模拟输入缓冲等等。下面是这些产品的基本分类：分辨率16位:AD7706,AD7707,AD7708,AD7709,AD7715,AD7788,AD7790,AD7792,AD779824位：AD7710,AD7711,AD7711A,AD7712,AD7713,AD7714,AD7718,AD7719,AD7730,AD7730L,AD7731,AD7732,AD7734,AD7738,AD7739,AD7782,AD7783,AD7787,AD7789,AD7791,AD7793,AD7794,AD7799多通道高数据输出速率：AD7731,AD7734,AD7738,AD7739低数据输出速率：AD7708,AD7714,AD7718,AD7794温度测量对于二极管和RTD测温，需要ADC内部有电流源热电耦：AD7719,AD7792/AD7793,AD7794二极管：AD7709RTD：AD7711,AD7719,AD7783,AD7792/AD7793,AD7794压力测量压力测量需要非常小的差分模拟输入范围，较高的参考输入范围以进行比例测量，有时还需要辅助ADC通道进行温度补偿。AD7710,AD7714,AD7719,AD7730,AD7798/AD7799电子秤AD7714,AD7719,AD7730,AD7730L,AD7798/AD7799低功耗AD7705/AD7706,AD7714,AD7715,AD7719,AD7787,AD7788/AD7789,AD7790/AD7791,AD7792/AD7793,AD7794,AD7798/AD7799高输入模拟输入电压范围(+/-10V)AD7707,AD7712,AD7713，AD7732,AD7734集成片上模拟前端缓冲AD7708/AD7718,AD7709,AD7719,AD7782,AD7783,AD7787,AD7790/AD7791双极性输入(+/-2.5V)AD7710,AD7711,AD7712管脚配置ADCAD7782,AD7783带内部参考源ADCASigma-DeltaADC常见问题解答中国技术支持中心电话：800-810-1742传真：800-810-1747Email：[e-mail]2AD7792，AD7793，AD7794带隔离的Sigma-Delta调制器AD7400，AD7401高速Sigma-DeltaADCAD7760,AD7762,AD77631.2参考资料AN-665:ChannelSwitchingUsingΣ-ΔADCs(pdf,86,886bytes)ThisapplicationnotereferstotheAD7708andAD7718.DatasheetsspecifytheupdaterateforΣ-ΔADCs.AN-664:AD7732/AD7734/AD7738/AD7739inLowPowerApplications(pdf,134,537bytes)ThisapplicationnoterefersonlytotheAD7739,butisalsogenerallyapplicabletotheAD7732,AD7734andAD7738.Thepurposeofthisapplicationnoteistoexplainhowtooptimizetheuseofthesepartsinpowersensitiveapplications.AN-663:AD7732/AD7734/AD7738/AD7739CalibrationRegisters(pdf,99,226bytes)ThisapplicationnoteconcentratesontheAD7739butisalsoapplicabletotheAD7732,AD7734,andAD7738.Thepurposeofthisapplicationnoteistoexplorethecalibrationregistersinmoredetailthanisfoundonthedatasheets.AN-662:InputLeakageCurrentinHighSpeedApplications(pdf,214,217bytes)AN-626:UsingtheAD7732/AD7734/AD7738/AD7739ChecksumRegister(pdf,108,708bytes)AN-616:AD9430EvaluationBoardModificationsforXTALOscillatorClocking(pdf,166,131bytes)AN-615:Peak-to-PeakResolutionVersusEffectiveResolution(pdf,71,761bytes)Thisapplicationnotedescribeseffectiveresolutionandpeak-to-peakresolutionandhighlightsthedifferencebetweenthesetwospecifications.AN-614:UsingtheAD7782inLowPowerApplications(pdf,95,638bytes)...ThisapplicationnotedescribeshowtousetheAD7782inportableorlowpowerapplication