毕业设计（论文）-基于单片机的程控放大器设计.docVIP

江西科技师范大学 毕业设计（论文） 基于单片机的程控放大器设计 年 级: 2014届 学 号: 姓 名: 专 业: 电子科学与技术 指导老师: 二零一四年六月 摘 要 本设计由直流稳压电源增益控制部分功率放大部分自动增益控制输入部分采用高速电压反馈型运放OPA642作跟随器提高输入阻抗，并且在不影响性能的条件下给输入部分加了保护电路。使用了多种抗干扰措施以减少噪声并抑制高频自激。利用可变增益宽带放大器AD603来提高增益和扩大AGC控制范围，通过软件补偿减小增益调节的步进间隔和提高准确度。功率输出部分采用分立元件制作。由51系列单片机、A/D、D/A和基准源组成整个系统通频带为1kHz～20MHz，最小增益0dB，最大增益80dB。增益步进1dB，60dB以下预置增益与实际增益误差小于0.2dB。不失真输出电压有效值达9.5V，输出4.5～5.5V时AGC控制范围为66dB应用单片机和数字信号处理技术对增益进行预置和控制,AGC稳定性好,可控范围大,完成了的所有基本Abstract The design of the DC power supply, the preamplifier circuit unit , gain control section , the power amplifier section , SCM AGC part of several modules . The input section with high-speed voltage feedback op amp OPA642 as a follower to improve the input impedance , and without affecting the performance of the conditions to the input section added protection circuit. Using a variety of measures to reduce noise interference and suppress high frequency self-excited . While taking advantage of the variable -gain broadband amplifiers AD603 to improve and expand the AGC gain control range , reducing the gain adjustment step interval and improve accuracy by software compensation. Power output section using discrete components , improving the load resistance and the output rms . Controlled in part by the 51 series micro controller , A / D, D / A and a reference source components. Passband of the entire system 1kHz ~ 20MHz, the smallest gain 0dB, the maximum gain 80dB. Gain step 1dB, 60dB gain with the following preset actual gain error is less than 0.2dB. Undistorted output voltage effective value of 9.5V, 4.5 ~ 5.5V output when the AGC control range of 66dB, the application micro controller and digital signal processing techniques to gain presets and control , AGC good stability , large controllable range , completed the design all the basic requirements and make the appropriate play to make the design better . Keywords: programmable ; broadba