摘要
基于单片机设计了一种可控放大器程控滤波器。可控放大部分以可控放大器PGA203为核心,实现输出增益的动态调整;程控滤波器以开关电容滤波器LMF100为核心,使用DDS芯片AD9850产生可变的时钟,实现滤波器的截止频率可调;幅频特性测试仪采用AD9850产生扫频信号,AD837进行有效值检测,TLC5510进行A/D转换;以STC12C5A32AD单片机为控制核心,利用键盘数码管和液晶屏实现增益和截止频率的预置,以及测试和显示功能。
A programmable filter with controllable amplifier is designed based on MCU. With PGA203 as the core,the dynamic adjust- ment of output gains are realized. AD9850 is used to produce a variable clock,and the programmable filte can adjust the cut-off frequency using switching capacity filter LMF100. In amplitude-frequency characteristic tester, AD9850 produces the swept-frequency signal, AD837 realizes the virtual value detection, and TLC5510 completes A/D conversion. Taking STC12CSA32RD as the core, using LCD and keyboard, the amplifier realizes the preset,test and display of the gains and cut-off frequency.
出处
《单片机与嵌入式系统应用》
2011年第5期63-66,共4页
Microcontrollers & Embedded Systems
