信号发生器的设计

摘  要 [资料来源：www.THINK58.com]

本系统设计一个信号采集器。，使用PIC16F877单片机作为中央控制器，PIC（Peripheral Interface Controller）是一种用来开发的去控制外围设备的集成电路（IC）。一种具有分散作用（多任务）功能的CPU。它的最高操作频率大约都在20MHz左右，存储器容量用做写程序的大约1K—4K字节。 [资料来源：http://THINK58.com]

传统的频率合成器，通常从一排晶振荡器采集的各种频率通过开关进行频率混合。也有的采用众所周知的锁相环(PLL)技术实现频率合成。随着数字技术的飞速发展，用数字控制方法从一个参考频率源采集多种频率，即直接数字合成技术(DDS)异军突起。本设计使用世界流行的美国ADI公司生产的AD9850频率合成器正是应用这种DDS技术的典型热门产品之一，AD9850采用先地蝗CMOS工艺，其功耗在3.3V供电时仅为155mW，扩展工业级温度范围为-40～80℃，采用28脚SSOP表面封装形式，结合DDS芯片AD9850，采集0～15MHz频率可调的信号；调制信号为1KHz的波，调制信号的采集采用DDS技术；系统采用全中文菜单操作方式，操作简单，快捷，且系统的精度和稳定性高。 [资料来源：THINK58.com] 

关键字：信号  PIC16F877  AD9850  DDS技术 

[资料来源：THINK58.com]

ABSTRACT

The system design a sine signal generator. Using PIC16F877 microchip as a central controller, PIC (Peripheral Interface Controller) is the method which used to control peripherals development of Integrated Circuits (IC). A CPU with scattered (multi-task) function . Its maximum operating frequency is 20MHz approximately about. The memory capacity of theprocedures used to write about 1K-4K bytes. [资料来源：http://think58.com]

The traditional frequency synthesizers, usually form a row of crystal oscillator frequency by switching from a variety of frequency mixed. Some used the well-known PLL technology to achieve frequency synthetic. With the rapid development of digital technology, using digital control methods form a variety of sources in a frequency reference frequency, direct digital synthesis techniques (DDS) sudden appearance as a new way. The design use the  popular American ADI cmopany’s production AD9850 frequency synthesizers. DDS technology is the application of this popular products typically . AD9850 used to control CMOS first, the power loss is only 155mW at 3.3V supply, the expansion of industrial grade temperature range for -40~80 degrees, 28 feet SSOP surface packaging used form of DDS chip AD9850, a 0~15MHz frequency communications signals to the neighboring letter; preparation of the sinusoidal wave 1KHz, a modem signals used DDS technology; Chinese menu system used throughout the operation, the operation simple, fast and high system accuracy and stability   [来源：http://www.think58.com]