DAC8831在恒电位仪电压扫描中的应用  

Application of DAC8831 in voltage sweep of potentiostat

作　　者：张雷[1,2] 赵茂密[1] 欧阳义芳[1] 蔡宏果[2] 

机构地区：[1]广西大学物理科学与工程技术学院,广西南宁530004 [2]广西教育学院数学与计算机科学系,广西南宁530023

出　　处：《电子设计工程》2011年第10期118-120,131,共4页Electronic Design Engineering

基　　金：广西青年基金(0832007);广西研究生教育创新计划资助项目(105930903079)

摘　　要：为实现恒电位仪给定电压低速扫描时电压高精度、线性好及降低设计成本,设计了一种简单可行的电压扫描系统。该系统以STC89C51为主控器件,通过单片机IO口模拟SPI通信接口来控制16位数模转换芯片DAC8831,DAC8831根据预先输入的D/A控制字将数字信号转换成模拟电压,借助于外部运放实现双极性电压输出。实验结果表明,该系统输出电压范围为-4～+4 V、电压分辨率可达0.125 mV,低速电压扫描线性度好,具有应用灵活、外围电路简单,可靠性高的特点。In order to achieve highly accurate voltage in the low sweep speed of voltage potentiostate given,excellent linearity,and reduce the design cost,this paper presented a simply and feasible voltage sweep system.The system used the STC89C51 as the main chip,the system wrote D/A control words into the 16 bit Digital-Analog converter DAC8831 chip to convert digital signal into voltage value by the SPI communication interface,the output voltage of DAC8831 was converted into a bipolar voltage by an external operation amplifier.Experimental results show that the output voltage range is-4～＋4V,voltage resolution is 0.125 mV,the system achieves excellent linearity in the low sweep speed of voltage,with the application of flexible and simple external circuit,high reliability.

关 键 词：DAC8831 单片机 恒电位仪 OPA277 

分 类 号：TP272[自动化与计算机技术—检测技术与自动化装置]