基于MSP430的非线性端口网络导纳测试仪的设计

Design of Nonlinear Network Admittance Tester Based on MSP430

本系统以MSP430单片机为控制核心,运用FPGA可编程逻辑器件及MSP430内部12位ADC实现对无源非线性端口网络导纳的测量。通过激励AD9850实现DDS信号输出,经AD811功率放大后,作为无源非线性端口网络的激励信号。将激励产生的电流信号经I/U转换后,分别送入AD637有效值检波电路和LM339整形电路,最后由ADC12采集检波后信号幅度,利用FPGA测量整形后电压信号的相位差,分别得到非线性端口网络的导纳数据,最终通过LCD显示无源非线性端口网络的导纳值与导纳角。

With FPGA programmable logic devices and MSP430 internal 12-bit ADC applied, the measurement of nonlinear network admittance is achieved based on MSP430. DDS output signal generated by AD9850 which is amplified by AD811 power amplification, is taken as an excitation signal of passive nonlinear port network. The corresponding voltage signals which is converted by I/U circuit are sent to a detection circuit and a shaping circuit. Finally, the nonlinear admittance port network data are obtained on the basis of the amplitude of signals collected by ADC12 detection. The admittance value and admittance angle are obtained and displayed on LCD12864 after measuring the phase difference between the voltage signals through the shaping circuit at the running of the system.