简易多功能数字存储示波器(蔡天 林立 苏鑫).doc

2007 电子设计大赛- 第 1 页 -简简易易多多功功能能数数字字示示波波 器器参赛学校： 武汉大学 参赛队员： 蔡天林立苏鑫时间：2007-7-27 赛前教师：黄根春 张望先 文稿教师：黄根春 徐大敏 摘要摘要 本系统基于数字示波器基本原理，以 8051 单片机和 FPGA 组成的最小系统为控制 核心；系统的频率范围为 1Hz～2.8MHz，使用高速 ADC 芯片对任意波形信号进行采样 量化，并在模拟示波器上显示，同时能对信号的基本参数进行数字测量，其中频率误 差优于 0.1％，幅度误差优于 5％；通过 FPGA 对量化值进行 FFT 运算，实现了对输入 信号的频谱分析；此外，本系统还可以利用傅立叶变换的性质对双通道输入的两路信 号进行相位差测量，误差小于 0.5o；实现周期信号的失真度测量，误差小于 1％；系 统的显示输出采用模拟示波器和 128*64 点阵液晶相结合的方式，连续可调电位器和 3*8 键盘为输入接口，故系统波形显示清晰，操作简单，界面友好 关键词：示波器FFT失真度测相 AbstractAbstract The system, mainly controlled by the combination of MCU 8051and ALTEA’s Cyclone FPGA, is based on the elements of Digital Oscillograph. All kinds of signal with the frequency fewer than 2.8MHz can be sampled by ADC chip AD9051 and AD197. The data of sampling is operated under FFT, with a result of the frequency spectrum of the input signal. Addition, the system also can measure the phasic difference, with the precision fewer than. We adopt the analog oscillograph and 128*64 dot-matrix LCD screens as export equipment, 3*8 keyboards and adjustable resistance as import equipment. People will find easy to handle the system with clear display and friendly interface. Keyword: oscillographFFT Audibility of Distortion2007 电子设计大赛- 第 2 页 -目录目录摘要............................................................................................................................................1Abstract....................................................................................................................................1 目录....................................................................................................................................................2 一、方案论证与选择........................................................................................................................3 1．题目任务要求及相关指标的分析......................................................................................3 2．方案的比较与选择..............................................................................................................3 二、系统总体设计方案及实现方框图............................................................................................5 三、理论分析与计算........................................................................................................................5 1、采样速率..............................................................................................................................5 2、幅度控制..............................................................................................................................5 3、波形的数据处理及相关参数测量......................................................................................5 4、快速傅立叶变换及误差......................................................................................................6 四、主要功能电路的设计................................................................................................................6 1、输入信号放大与采样量化电路..........................................................................................6 2、同步采样时钟产生电路......................................................................................................7 3、水平垂直 div 调节电路......................................................................................................7 4、模拟示波器显示电路..........................................................................................................7 五、系统软件的设计........................................................................................................................7 六、测试数据与分析........................................................................................................................8 1．使用仪器及型号..................................................................................................................8 2．测试方案..............................................................................................................................8 3．测量数据及结果分析..........................................................................................................8 七、总结分析与结论........................................................................................................................9 1、题目要求完成情况..............................................................................................................9 2、调试总结..............................................................................................................................9 八、附录..........................................................................................................................................10 1、电路原理图........................................................................................................................10 2、参考文献............................................................................................................................112007 电子设计大赛- 第 3 页 -一、方案论证与选择一、方案论证与选择 1．题目任务要求及相关指标的分析 (1)题目要求仪器的输入阻抗大于 100kΩ，我们可以使用一级射级跟随器或者同 相放大器来实现；垂直刻度为 8div，分辨率为 32 级/div，要求设置 0.01V/div、0.1V/div、1V/div 三档垂直灵敏度，误差≤5%，即直流档时输入信号电 压范围为-4V～+4V，交流档时输入信号峰峰值范围为 0V～8V。