基于AD9834的简易信号源设计

The Design of Simple Signal Source Based on AD9834

采用模拟电路设计的信号源存在频率精度不高、调试与维修不方便以及直接升级困难等缺点。为了克服这些缺点,提出利用直接数字频率合成技术(AD9834)产生要求的正弦测井激励信号,利用小功率低压器件的串联实现信号的大功率大电压输出,利用电源跟踪技术在一定程度上降低功率器件的损耗,提高电路的工作效率。实验结果表明,信号源输出频率1～15Hz,频率分辨率为0.004Hz。

The signal source designed by the analogue circuit has some defects like the low accuracy of frequency,the inconvenience in debugging and maintaining,the difficulty of direct upgrade and so on. In order to overcome these shortcomings,it is proposed that the direct digital frequency syntheses technique （AD9834） should be applied to the production of the required sine logging exciting signals. It is also suggested that series devices of low power and voltage are used to the output of signals with high power and high voltage,and that power tracking technique should be adopted so as to lower the wastage of power devices and improve the working efficiency of circuit to some degree. The result of experiment shows that the output frequency of signal source is 1～15 Hz,and the frequency resolution is 0.004Hz.