直接数字频率合成技术在超声波振荡电路中的应用

摘要

In view of the problem that output frequency of traditional ultrasonic oscillation circuit is unstable because of using analog or digital self-excited oscillator, the paper proposed a design scheme of ultrasonic oscillation circuit based on direct digital frequency synthesis technology, and introduced basic working principle of direct digital frequency synthesis technology and implementation of hardware and software of the ultrasonic oscillation circuit in details. The practical application showed that the ultrasonic oscillation circuit with direct digital frequency synthesis chip AD9850 is stable and reliable, and is less susceptible to changes of temperature and humidity, which can completely solve the problem of frequency drift of ultrasonic oscillation circuit of mine-used instrument.%针对传统的超声波振荡电路因采用模拟或数字自激振荡器存在输出频率不稳定的问题,提出了一种采用直接数字频率合成技术设计超声波振荡电路的方案,详细介绍了直接数字频率合成技术的基本工作原理以及采用该技术设计的超声波振荡电路的硬件和软件实现.实际应用表明,采用直接数字频率合成芯片AD9850设计的超声波振荡电路稳定可靠,并且不易受温湿度变化的影响,能解决矿用仪器仪表电路中超声波振荡电路的频率漂移问题.