摘要
介绍了直接数字频率合成(DDS)信号源的设计。该系统分成3个主要模块,分别是:直接数字频率模块,键盘和LCD控制模块和低通椭圆滤波模块。基于单片机有足够的空闲输入输出引脚,DDS模块中的AD9851采用并行工作模式。在低通椭圆滤波模块,采用了基于反归一法设计的截止频率为25MHz的低通椭圆滤波器。最后附上了电路图和系统产生的波形图。
In this paper,a design of signal source of direct digital frequency synthesis（DDS） is presented.The system is divided into three main modules;DDS module,keyboard and LCD control module and low-pass elliptic filter module.In DDS module,AD9851 is designed to work in parallel mode for the MCU which can provide enough free I/O pins for it.In low-pass elliptic filter module,a new design of a low pass filter of 25MHz of cut-off frequency is proposed by antinormalization.The circuit diagram and waveform diagram of the device are shown in the end of the paper.
出处
《机械制造与自动化》
2011年第1期135-137,共3页
Machine Building & Automation
