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TILMP92064模拟前端电流、电压采样参考设计方案关键字：模拟前端电流,低端数据电流TI公司的LMP92064是一款具有SPI接口的高精度低端数据电流、电压监测模拟前端芯片，该芯片通过内部精确电流传感器运放测量通过负载的分流器电阻电流量，并通过缓冲电压通道测量负载电压源。电流、电压采样为12位ADC采样，速率为同步125ksps，内部集成2.048V的ADC参考电压，在单向传感器计量中可以获得非常高精度的功率计算结果。本文首先介绍芯片的简介、特性、内部框图及应用领域，并给出相应设计方案的设计原理图、元器件列表及PCB元件布局图。TheLMP92064isaprecisionlow-sidedigitalcurrentsensorandvoltagemonitorwithadigitalSPIinterface.Thisanalogfront-end(AFE)includesaprecisioncurrentsenseamplifiertomeasurealoadcurrentacrossashuntresistorandabufferedvoltagechanneltomeasurethevoltagesupplyoftheload.Thecurrentandvoltagechannelsaresampledsimultaneouslybyindependent125kSps12-bitADCconverters,allowingforveryaccuratepowercalculationsinunidirectionalsensingapplications.TheLMP92064includesaninternal2.048VreferencefortheADCs,eliminatingtheneedofanexternalreferenceandreducingcomponentcountandboardspace.AhostcancommunicatewiththeLMP92064usingafour-wireSPIinterfacerunningatspeedsofupto20MHz.ThefastSPIinterfaceallowstheusertotakeadvantageofthehigherbandwidthADCtocapturefastvaryingsignals.Thefour-wireinterfacewithdedicatedunidirectionalinputandoutputlinesalsoallowsforaneasyinterfacetodigitalisolatorsinapplicationswhereisolationisrequired.TheLMP92064operatesfromasingle4.5Vto5.5Vsupplyandincludesaseparatedigitalsupplypin.TheLMP92064isspecifiedoveratemperaturerangeof–40°Cto105°C,andisavailableina5mmx4mmWSON-16package.LMP92064主要特性：TwoSimultaneousSampling12-bitADCsConversionRate:125kSps(Min)12-bitCurrentSenseChannelInput-referredOffset:±15µVCommon-modeVoltageRange:–0.2Vto2VMaximumDifferentialInputVoltage:+75mVFixedGain:25V/VGainError:±0.75%(Max)Bandwidth(–3dB):70kHzDCPSRR:100dBDCCMRR:110dB12-bitVoltageChannelINL:±1LSBOffsetError:±2mV(Max)GainError:±0.75%(Max)MaximumInputVoltage:+2.048VBandwidth:100kHzInternalReferenceSPIFrequency:Upto20MHzTemperatureRange:–40℃to+105℃WSON-16PackageLMP92064应用：EnterpriseServersTelecommunicationsPowerManagement图1.LMP92064内部方框图LMP92064方案原理图：图2.LMP92064方案原理图LMP92064方案材料清单：PCB元件布局图：AO-Electronics傲壹电子官网：中文网：