1、 毕毕毕 业业业 设设设 计计计（论论论 文文文） （ 2 2 20 0 01 1 13 3 3 届届届） 题题 目：目： 小信号放大电路的探究小信号放大电路的探究 专专 业：业： 电子信息工程电子信息工程 姓姓 名：名： XXXXXXXX 学学 号：号： XXXXXXXX 指导教师：指导教师： 职职 称：称： 教授教授 填写日期：填写日期： 20132013- -0404- -30 30 第 1 页 摘 要 目前，小信号放大电路的应用极其广泛，小到音箱、收音机等民用行业，大到卫星、 火箭等军用行业。它不仅使我们的日常生活更加丰富多彩，而且对经济、国防等做出了 不可磨灭的贡献。然而小信号有它自
2、身的缺陷，由于它本身的能量较小，容易被噪声淹 没或受到外界的干扰，而且对小信号放大电路设计的难处主要在高性能运算放大器。运 算放大器性能的优劣决定该电路的性能。与国外相比国内对运算放大器的研究比较落 后，导致对小信号放大电路的研究处于落后状态。 基于 OPA842ID，本设计介绍了小信号放大电路的探究与设计。该电路由五个 OPA842ID 组成的输入级差分放大电路、 中间级电压放大电路和输出级功率放大电路完成 对小信号的采集、 电压放大和功率放大。 同时有效的抑制或消除电路的温漂和共模信号， 使放大后的信号失真度较小。设计好后的电路，使用 Multisim 电路仿真软件对其进行 仿真。通过施加
3、正弦小电压信号，从电路的静态工作点分析，交流分析等方面仿真，得 出电路的电压增益、带宽等仿真结果，进一步验证了电路理论设计的正确性和可行性。 关键词：小信号 放大电路 OPA842ID Multisim 第 2 页 Abstract Currently, the application of the small signal circuit is extremely wide, small to speakers, radios and other civilian industry, large to satellites, rockets and other military indust
4、ry. It not only makes our daily life more colorful, but also made an indelible contribution to the economic, defense and others. However, the small-signal has its own flaws, because of itself smaller energy, it is easy to drown by the noise or interference by outside. And the main difficulty of smal
5、l signal amplification circuit design is high-performance operational amplifier. The pros and cons of the operational amplifier performance determine the performance of the circuit. Compared with foreign countries, the domestic operational amplifier is relatively backward, lead to the study of the s
6、mall-signal amplifier circuit in a backward state. Based on OPA842ID，this design introduces a small signal amplification circuit of inquiry and design. The circuit is composed by five OPA842ID input level differential amplifier circuit, the intermediate stage voltage amplifying circuit and the output stage power amplifying circuit to complete the acquisition of the small signal, the vol
