郑州交通职业学院毕业论文（设计）论文（设计）题目低噪声高效率音频功率放大器的设计所属系别信息工程系专业班级 10级大专电子信息工程1班姓名郭向前学号 20指导教师辛云霞撰写日期 2013 年 4 月I摘要电子信息技术几乎主宰了整个电器行业的发展，随着电子技术的进步发展在功率放大器的设计上功能也不断更新。
功率放大器在家电、数码产品中的应用也越来越广泛，与我们日常生活有着密切关系。
随着生活水平的提高，人们越来越注重视觉，音质的享受。
在大多数情况下，增强系统性能，如更好的声音效果，是促使消费者购买产品的一个重要因素。
音频功率放大器作为音响等电子设备的后级放大电路，它的主要作用是将前级的音频信号进行功率放大以推动负载工作，获得良好的声音效果。
同时音频功率放大器又是音响等电声设备消耗电源能量的主要部分。
目前，音频功率放大器仍以模拟功放为主流产品，模拟功放经历了数十年的不断改进和完善，其技术已发展到了顶峰。
模拟类功放是以线性放大为基础，功率放大器件有电子管和晶体管两类。
按功放静态工作点的设置可分为Ａ类放大，Ａ/Ｂ类放大和C类放大三种。
晶体管功放的最大优点是电源转换效率高（C类功放最大可达55%）、体积小、重量轻、发热量不大、生产成本低。
缺点是转换速率低、偶次谐波失真较大。
音质和可靠性指标都略逊于电子管功放。
随着晶体管制造技术的不断提高和新技术的应用，各项实用性指标和可靠性指标都有很大改善，并不断在向更大的输出功率、更小的体积、更轻的重量、更多的功能和智能化方向发展。
关键词：音频功率放大器的设计，晶体管功放，电子管功放IIAbstractElectronic information technology is almost dominated the entire electrical industry, with the progress and development of electronic technology in the design of power amplifier features are constantly updated. Power amplifiers in home appliances, digital products are increasingly being used in applications, and is closely related to our daily life. With the improvement of living standards, there is growing emphasis on visual and sound quality to enjoy. In most cases, enhanced system performance, such as better sound effects, is to promote consumers to buy products, an important factor. Stereo audio power amplifier and other electronic equipment as a post-stage amplifier circuit, its main role is to level the audio signal before the power amplifier in order to promote the work load, get a good sound. Stereo audio power amplifier is also electro-acoustic devices such as the main part of the energy consumption of power.Currently, analog amplifier audio power amplifier is still the mainstream products, analog amplifier has experienced decades of continuous improvement and perfection, and its technology has been developed to its peak. Analog class-based power amplifier is a linear amplifier, power amplifier parts are two types of tubes and transistors. Amplifier quiescent point according to the settings can be divided into Class A amplification, A / B Class C Class zoom in and zoom of three. The biggest advantage of the transistor amplifier is a power conversion efficiency (C class power amplifier up to 55%), small size, light weight, less heat, low production costs. The disadvantage is the low conversion rate, even higher harmonic distortion. Sound quality and reliability of the indicators are slightly inferior to tube amp. With the continuous improvement of transistor manufacturing technology and new technology, the availability and reliability targets have greatly improved, and continue to the higher output power, smaller size, lighter weight, more multi-functional and intelligent direction.Keywords:Audio Power Amplifier，the transistor amplifier，tube ampIII目录Abstract -------------------------------------------------------------------------------------------- I II1 引言 ---------------------------------------------------------------------------------------------- 12 音频放大器的简介------------------------------------------------------------------------------ 1音频放大电路的回顾和展望 -------------------------------------------------------------------------------- 1音频功率放大电路的简介------------------------------------------------------------------------------------ 2音频放大器分类 ------------------------------------------------------------------------------------------------ 32.3.1 A类(甲类)放大器----------------------------------------------------------------------------- 32.3.2B类(乙类)放大器 ----------------------------------------------------------------------------- 32.3.3 AB类(甲乙类)放大器------------------------------------------------------------------------ 43 放大器常见名词--------------------------------------------------------------------------------- 4灵敏度------------------------------------------------------------------------------------------------------------- 4阻尼系数 --------------------------------------------------------------------------------------------------------- 4反馈---------------------------------------------------------------------------------------------------------------- 4负反馈------------------------------------------------------------------------------------------------------------- 5正反馈------------------------------------------------------------------------------------------------------------- 5动态范围 --------------------------------------------------------------------------------------------------------- 5响应---------------------------------------------------------------------------------------------------------------- 5信噪比(S/N) ------------------------------------------------------------------------------------------------------ 5屏蔽---------------------------------------------------------------------------------------------------------------- 5阻抗匹配 --------------------------------------------------------------------------------------------------------- 6 4 总体方案设绍------------------------------------------------------------------------------------ 6总体方案论证 --------------------------------------------------------------------------------------------------- 6单元模块方案论证与比较------------------------------------------------------------------------------------ 74.2.1波形变换电路------------------------------------------------------------------------------------ 74.2.2弱信号前置放大级 ------------------------------------------------------------------------------ 84.2.3功率放大级--------------------------------------------------------------------------------------- 84.2.4 自制稳压电源------------------------------------------------------------------------------------ 9方案选择 --------------------------------------------------------------------------------------------------------- 9 5 单元模块设计------------------------------------------------------------------------------------ 9各单元模块功能介绍及电路设计 -------------------------------------------------------------------------- 95.1.1弱信号前置放大级电路 --------------------------------------------------------------------- 115.1.2功率放大电路---------------------------------------------------------------------------------- 135.1.3自制稳压电源电路 --------------------------------------------------------------------------- 15特殊器件的介绍 ---------------------------------------------------------------------------------------------- 15 6结束语-------------------------------------------------------------------------------------------- 17参考文献------------------------------------------------------------------------------------------- 17 III致谢 ----------------------------------------------------------------------------------------------- 18 IV1 引言音频放大器已经有快要一个世纪的历史了，最早的电子管放大器的第一个应用就是音频放大器。
