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.
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)
