基于Multisim的直接数字频率合成器的设计与仿真

Design and Simulation of Direct Digital Frequency Synthesizer Based on Multisim Software

为了方便、直观地了解频率合成技术,对由相位累加器、波形存储ROM、D/A转换器和低通滤波器等模块构成的直接数字频率合成器(DDS)进行了研究。利用Multisim提供的强大虚拟电子平台,实现以80C52单片机为控制中心、合成正弦波的DDS的设计和电路仿真。通过调整参考时钟频率fc、或者调整频率控制字K,可以清楚地看到合成正弦波的频率随之而改变。这种设计、仿真过程摆脱了实验设备及场地的限制,可作为相关专业本科生的课程设计,也可以作为传统实验的前期工作,以提高学习效果和实验效率。

In order to get the technology of frequency composition intuitively,direct digital frequency synthesizer(DDS) composed of phase accumulator,waveform store ROM,D/A converter and low pass filter etc.was studied.Based on Multisim software,a DDS outputs sine-waveform controlled by single chip 80C52 was designed and simulated.It can be clearly found that the frequency of output waveform changes with adjusting the referenced clock frequency f and the frequency control word K.It is convenient and easy to realize electronic circuits design and simulation without regard to lab equipments.This can be used for undergraduates' course design or the pre-design of traditional experiment to improve study effect and experiment efficiency.