程控低通滤波器的设计大学生毕业设计（论文）.doc

本科学生毕业设计 控低通滤波器的设计 院系名称： 电气与信息工程学院 专业班级： 电子信息工程11-2班 学生姓名： 恒坤 指导教师： 职 称： 黑 龙 江 工 程 学 院 二一五年六月 The Graduation Design for Bachelors Degree Design of rogram Controlled Low Pass Filter Candidate：Ma Hengun Specialty：Electronic Information Engineering Class：11-2 Supervisor：Liu Jingsen Heilongjiang Institute of Technology 2015-06·Harbin  摘 要 本设计基于单片机的程控低通滤波器系统方案的设计思想和实现方法。系统以高性能、低成本AT89LV52为核心控制器配合CD4051模拟开关实现程序控制选择滤波电路的设计方法。利用LM358AD运算放大器设计两个电压跟随器利用其输入阻抗高等特点实现频率信号的缓冲与隔离干扰的作用，然后让信号输入运放的正相端，利用LM358AD实现同相输入的压控电压源二阶低通滤波电路，最后将滤波的结果用液晶进行显示。 本设计首先简单介绍了程控低通滤波器的发展现状，结合系统设计方案的要求，详细论证了实现二阶低通滤波器方案的设计思路及系统的总体架构然后详尽地阐述了系统的硬件电路结构和完成各项功能相关的软件设计最后利用Multisim软件进行了电路仿真。系统结构简单，可靠性高，功能易扩展，适用于多种应用领域。 关键字：89LV52；电子开关；LM358AD；；Multisim  ABSTRACT This design the design idea and realization method of the programmable low pass filter system scheme based on MCU. The system takes the AT89LV52 as the core controller featured with high performance and low cost coordinated with the CD4051 simulation switch to realize the design method of choosing the filtering circuit with program control. With the help of two voltage follower featured with input impedance and LM358AD operational amplifier, achieve the role of frequency signal buffer and isolation interference, then let the signal enter the positive phase. Utilize LM358AD to realize the second-order low-pass filter circuit of voltage control source with non-inverting input. Finally, the results of the filter are displayed with LCD. The subject of this design is n low-pass filter with program control in combination with the system design requirements. Demonstrate the design idea and the overall framework of the second-order low-pass filter in detail, then, describe the hardware circuit structure and the software design of the system in detail. At last, the circuit simulation is carried out using Multisim software. The system has the advantages of simple structure, high reliabilit