直接数字频率合成器的PFGA实现

Direct Digital Frequency Synthesizer Implemented with FPGA

系统采用Xilinx公司生产的型号为XC3S200的FPGA芯片和Maxim公司生产的型号为MAX5885的专用D/A芯片,利用直接数字频率合成技术,通过Xilinx公司的ISE 9.2开发软件,完成DDS核心部分即相位累加器和ROM查找表的设计。可得到相位连续、频率可变的信号。经过电路设计和模块仿真,验证了设计的正确性。由于FPGA的可编程性,使得修改和优化DDS的功能非常快捷。

By means of the direct digital synthesis technology, the design of the phase accumulator and ROM lookup table （both of them are the cores of DDS） is achieved with the ISE 9.2 development software and FPGA chip xc3s200 produced by Xilinx Company, as well as D/A converter MAX5885 produced by Maxim. The phase continuous and frequency variable signal can be obtained with the design scheme. The validity of DDS was verified by the circuit design and module simulation. As the advantage of the programmability of FPGA,it is convenient to modify and optimize the function of DDS.