标签: SigmaDelta

带通Sigma-Delta调制器的模拟延时器Simulink建模

SigmaDeltaADC10/31/200110AM_GSaOneTechnologyWayP.O.Box9106Norwood,MA02062-9106Tel:781/329-4700Fax:781/326-8703www.analog.comCircuitSuggestionsusingFeaturesandFunctionalityofNewSigma-DeltaADCsPart1ByJohnWynneInmanymoderncost-competitivemarketsfromFieldThiswhitepaperdescribeshowthefeaturesandfunc-InstrumentsthroughDataAcquisitionandontoIndus-tionalityofthesedevicescanbeusedtosolveeverydaytrialandhand-heldInstrumentation,therearedesigntasksinasimplerandmorecost-effectiveman-pressurestobothincreasemeasurementthroughputnerthaneverbefore.Thetreatmentofthesediff……

为了能处理X-ray安检系统中微弱的探测信号，需要设计一款精度高达14bit的调制器。文中采取了三阶Sigma-Delta调制器结构，该调制器采用过采样和噪声整形技术来实现高精度，在信号带宽20kHz，过采样率256，时钟10.24MHz的情况下，MatlabSimulink建模仿真结果表明，该调制器SNR可以达到104.6dB，精度可达17bit。通过对调制器非理想性分析，采用TSMC0.25μm工艺实现整个调制器的管级电路，并通过CadenceSpectre后仿真，仿真结果SNR可达到98dB，即精度为16bit，满足X-ray安检系统14bit的精度要求。