基于FPGA和LabWindows的音频DAC测试方案开发与实现

Development and Implement of Audio DAC Testing Based on FPGA and LabWindows

电子设备集成度的提高对于音频集成电路生产和测试等环节的要求越来越高,尤其是音频数模转换器(Digital to Analog Converter,DAC),本质上为数模混合信号电路,采用数模混合信号自动化测试设备(Automatic Test Equipment,ATE)价格昂贵,而采用传统自动测试仪测试覆盖率低、测试时间长,导致这类电路的测试成本较高且测试产能不足。介绍了一种基于现场可编程门阵列(Field Programmable Gate Array,FPGA)和LabWindows的音频DAC电路测试方案,硬件上用FPGA实现音频测试所需的直接数字频率合成(Direct Digital Frequency Synthesizers,DDFS)模块,软件上通过运用LabWindows自带的采样、加窗、快速傅里叶变换(Fast Fourier Transform,FFT)等数字信号处理函数,快速准确地测试各项模拟参数,并在用户界面(User Interface,UI)显示测试值和后台保存测试数据。

With the improvement of the integration of electronic equipment,the requirements for the production and testing of audio integrated circuits are getting higher and higher.In particular,the audio Digital to Analog Converter(DAC)is a mixed-signal circuit,and the Automatic Test Equipment(ATE)with mixed-signal is expensive,while the traditional automatic tester has low test coverage and long test time,which leads to high test cost and insufficient test capacity.This paper introduces an audio DAC circuit test scheme based on Field Programmable Gate Array(FPGA)and LabWindows.The hardware uses FPGA to realize the direct digital frequency synthesizers(DDFS)module needed for audio test.In the sofware,by using the digital signal processing functions such as sampling,windowing and Fast Fourier Transform(FFT)that LabWindows comes with,various analog parameters can be tested quickly and accurately,and the test values can be displayed in the User Interface(UI)and the test data can be saved in the background.