简易多功能数字示波器参赛学校：武汉大学参赛队员：蔡天林立苏鑫时间：2007-7-27赛前辅导教师：黄根春张望先文稿辅导教师：黄根春徐大敏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AbstractThesystem,mainlycontrolledbythecombinationofMCU8051andALTEA’sCycloneFPGA,isbasedontheelementsofDigitalOscillograph.Allkindsofsignalwiththefrequencyfewerthan2.8MHzcanbesampledbyADCchipAD9051andAD197.ThedataofsamplingisoperatedunderFFT,witharesultofthefrequencyspectrumoftheinputsignal.Addition,thesystemalsocanmeasurethephasicdifference,withtheprecisionfewerthan.Weadopttheanalogoscillographand128*64dot-matrixLCDscreensasexportequipment,3*8keyboardsandadjustableresistanceasimportequipment.Peoplewillfindeasytohandlethesystemwithcleardisplayandfriendlyinterface.Keyword:oscillographFFTAudibilityofDistortion目录摘要..........................................................................................................................................1Abstract..................................................................................................................................1目录..................................................................................................................................................2一、方案论证与选择.......................................................................................................................31．题目任务要求及相关指标的分析.....................................................................................32．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.......................................................................................................................51、采样速率............................................................................................................................52、幅度控制............................................................................................................................53、波形的数据处理及相关参数测量.....................................................................................54、快速傅立叶变换及误差.....................................................................................................6四、主要功能电路的设计...............................................................................................................61、输入信号放大与采样量化电路.........................................................................................62、同步采样时钟产生电路.....................................................................................................73、水平垂直div调节...
