程控滤波器(D题)
摘要:本设计根据题目要求,在分析论证了各种方案之后,以单片机和可编程数字滤波器芯片为核心,设计了一个程控滤波器。该程控滤波器主要由三个模块构成:放大电路、,实现了步进为10dB的0到60dB的可调增益。滤波器部分以可编程开关电容滤波器MAX262芯片为核心,,实现了截止频率1KHZ—20KHZ步进1HZ可调的程控滤波器,各项误差低于5%,符合要求.
关键字:开关电容滤波器,放大器,MAX262,DDS
Abstract: According to the requirements of this design, after various programs are analyzed , we design a programmable filter, which is at the core of a microcontroller and DDS。 The programmable filter consists of three main components: amplifier, filter and SCM display and control module。The enlarger part passes the single a machine to selects by examinations to the feedback electric resistance resistivity, realizing the step enter to 10 dBs of 0 to 60 dBs of adjustable increase the benefit。 The filter part regard programmable switch electric capacity filter MAX262 slice as the core,, realizes to close the frequency a step control the filter into an adjustable distance, various error margins is lower than 5%, meeting the request。
Keywords: Switch electric capacity filter ,Amplifier,MAX262 ,DDS
引言
滤波是信号采集、数据处理和通信系统等领域必不可少的重要环节。在许多工程应用领域,信号频率的动态范围很宽,这就有必要采用多种截止频率的滤波器,用程控的方法对频率动态范围宽的信号进行滤波。本方案设计一种放大器增益可设置,低通或高通滤波器通带、截止频率等参数可设置的程控滤波器。
1.系统方案论证与比较
根据题目的要求,根据上述方案论证的结论,制定出整体系统的设计方案:
放大部分采取2级放大组合来获得0DB至60DB步进为10DB的增益。(1)所示。
图(1) 系统整体框图
1。2方案论证
1。21放大
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