低功耗运算放大器降低电缆成本的pH探头

摘要：该电路显示了如何使用一个MAX406CMOS运算放大器非常高的输入阻抗非常高的输出阻抗缓冲pH值探头。所具备的优势，是一个标准的低成本电缆代替高成本的聚四氟乙烯介质同轴电缆的使用。该电路可连续数千小时的单节锂电池供电，电池的消耗是如此之低。驾驶一台液晶显示器显示的MAX130A集成ADC的使用。Maxim>AppNotes>AmplifierandComparatorCircuitsSensorsKeywords:op-amp,lowpower,buffer,pHprobe,integratingADC,analogtodigitalconverter,opamps,opampNov21,2000APPLICATIONNOTE34Low-PowerOp-AmpReducesCableCostsforpHProbeAbstract:Thecircuitshowshowtousetheveryhigh-inputimpedanceofaMAX406CMOSopamptobuffertheextremelyhigh-outputimpedanceofapHprobe.Theadvantagegainedistheuseofastandardlow-costcableinsteadofahigh-costTeflondielectriccoaxcable.Batterydrainissolowthatthecircuitcanbecontinuouslypoweredforthousandsofhoursonasinglelithiumcell.UseofaMAX130AintegratingADCisshownfordrivingaLCDdisplay.TheextremelyhighsourceimpedanceofapHprobe(1012Ω)oftenmandatest