基于直接数字频率合成芯片的正弦信号发生器

Sinusoidal signal generator based on direct digital frequency synthesis chip

本文论述了一个基于直接数字频率合成芯片AD9850,采用可编程门阵列FPGA设计完成的正弦信号发生器。该信号发生器包括信号产生部分、信号调理部分、信号处理部分和人机界面等4个部分。程序设计采用硬件描述语言VHDL,在ALTERA公司的Cyclone系列的EP1C6芯片上编程实现。经测试,该正弦信号发生器输出频率范围为1 kHz^10 MHz,输出幅度在50Ω负载上达VOPP≥1 V,具有频率设置步进功能、AM和FM调制功能,可产生二进制PSK和ASK信号。整机功能齐全,输出波形稳定,没有明显失真。

This article elaborated sinusoidal signal generator which based on the chip AD9850 with direct digital frequency synthesis, designed with programmable gate array FPGA. This signal generating device included production of the signal, signal recuperation part; signal processing part and man-machine contact surface and so on. The programming useed hardware description language VHDL, the programming carried out in ALTERA Corporation＇s Cyclone on the series EP1C6. After tested, this sinusoidal signal generator output frequency range is 1 kHz～10 MHz, Output amplitude in load of 50 Ω reaching higher authorities VOPP ≥1 V, Has the frequency establishment to step-bystep the function, With AM FM modulation function, May have the binary PSK and ASK signal. The machine function is complete, output wave shape is stable and don＇t have the obvious distortion.