多功能信号发生器 毕业设计论文.doc

摘要 多功能信号发生器是是一种常用的信号源，能产生模拟电压波形，广泛地应用于电子电路、自动控制系统和教学实验等领域。且特殊波形发生器的价格昂贵。目前使用的信号发生器大部分是函数信号发生器，它具有价格低、性能高和在低频范围内稳定性好、操作方便、体积小、耗电少等特点。 本设计信号发生器采用AT89S52单片机作为控制核心，外围采用了包括电源模块、数字/模拟转换电路（DAC0832）、运放电路（LM324）、键盘模块等。设计采用AT89S52单片机和一片DAC0832数模转换器以及一些外围电路组成低频信号发生器。此发生器能产生从1HZ-1MHZ的低失真正弦波，三角波，方波，矩形波，锯齿波等信号。输出波形的频率和种类可用程序控制改变。在单片机上加外围按键，通过按键控制波形频率的增减以及波形的选择。在单片机的输出端口接DAC0832进行D/A转换，再通过运算放大器进行波形幅度调整，最后输出波形接在示波器上显示。 本设计根据要求主要研究了软件编程实现波形和频率的可调。外围电路实现数模转换和信号波形放大。由于采用了LM324运算放大器和稳压电路，使其电路更加具有较高的稳定性能，性能比高。此电路清晰，出现故障容易查找错误，操作简单、方便。具有典型性。 [关键词]：函数信号发生器；单片机； DAC0832；AT89S52 Abstract Signal generator is a common signal source, can produce an analog voltage waveform，widely used in electronic circuits, automatic control systems, and teaching experiments and other fields. waveform generator and a special price of expensive . Currently used mostly function signal generator signal generator。it has low cost, high performance and good stability at low frequency within the range, easy operation, small size, power consumption and so on.  The design generator using AT89S52 microcontroller as the control, external analog / digital conversion circuit (DAC0832), operational amplifiers circuit (LM324), buttons and LCD liquid crystal display circuit.，etc..Design using AT89S52 microcontroller and a DAC0832 DAC as well as some peripheral circuit a low period of wave. The generator can produce from the 10-100HZ ,200-2000HZ, low-distortion sine wave, triangle wave, square wave signal, etc.. the period of wave can be controlled by procedure, at outer circle spare part of the machine, plus independence type keyboard , which can control wave increase or decrease of form-frequency and the choice of wave-form, at the same time LED display frequency size. The output of the machine connect DAC0832 to carry on a DA conversion，again pass operation amplifier to put an end exportation wave-form. The major design required study a software programming waveform and frequency adjustable. External digital-a