音响低频功率放大器毕业设计

IHI-FI高音质功率放大器的设计专业班级：063电子信息工程学号：7020906132姓名：殷杰指导老师：方安安摘要：高保真功率放大技术的发展，使整个音频功率放大技术领域发生了巨大的变化。现代人对听觉水平要求越来越高，所以对音响的音质真实性要求越来越多，高保真音频功率放大技术克服了这个缺点，它能够如实的反映出声音信号的音色，音高和音强等音质状况本来面貌的能力，同时对声音信号进行必要的修饰和加工，因此，我们这次的研究对象是高保真功率音质放大技术，本文主要介绍LM1875音频放大器的设计，它在音频应用场合提供非常低的失真度和高质量的音色，还具有了高增益、快速转换速率、宽功率带宽、大输出电压摆幅、大电流能力和非常宽的电源范围等特性。系统采用大回环电压负反馈控制输出，配以普通双路桥式整流滤波电路，放大器采用内部补偿，增益控制在26dB左右。它可用与高品质音频系统、立体声唱机等等[1]。关键词：LM1875高保真功率放大HI-FIhigh-qualityPowerAmplifierAbstract：High-fidelityaudiotechnology,audiotechnology,thewholehasundergonetremendouschanges,whichnotonlycombinestheaudiotechnologyandamplifiertechnology,modernpeopleincreasinglyhighdemandonthehearinglevel,sotheauthenticityoftheaudiosoundqualityhavebecomeincreasinglydemandingmore,high-fidelitysoundtoovercomethisshortcoming,itcanhonestlyreflectthevoicesignaltone,pitchandsoundqualityandstrongcapacitytofacethecondition,whilethesoundsignalandprocessingthenecessarymodifications,sothistimewestudyisthehigh-fidelityaudio,thisarticleintroducestheLM1875audioamplifierdesign,whichinaudioapplicationswithverylowdistortionandhigh-qualitysound,alsohasahighgain,fastslewrate,widepowerbandwidth,largeoutputvoltageswing,highcurrentcapabilityandverywidesupplyrangeandothercharacteristics.Usinglargeloopnegativefeedbackcontrolvoltageoutput,togetherwiththeordinarytwo-waybridgerectifierfiltercircuit,amplifierwithinternalcompensation,gaincontrolisabout26dB.Itcanbeusedwithhigh-qualityaudiosystems,stereoplayerandsoon.Keywords:LM1875High-fidelitypoweramplifier目录摘要..............................................................................................................................IAbstract.........................................................................................................................I第一章绪论.............................................................................................................11.1音频放大电路的回顾和展望.......................................................................11.2音频功率放大电路的简介...........................................................................11.3音频放大器分类...........................................................................................2第二章放大器常见名词.........................................................................................42.1输出功率.......................................................................................................42.2频率响应.......................................................................................................52.3失真...............................................................................................................52.4动态范围.......................................................................................................52.5信噪比...........................................................................................................52.6输出阻抗和阻尼系数...................................................................................52.7灵敏度...........................................................................................................52.8反馈...............................................................................................................62.9屏蔽...............................................................................................................6第三章音频放大器的设计.....................................................................................63.1设计要求.......................................................................................................63.2设计过程.......................................................................................................6第四章LM1875的简介........................................................................................154.1LM1875中文资料(引脚图，性点,参数及应用电路)................................154.2LM1875的工作原理：...............................................................................154.3LM1875的电路特点...................................................................................16第五章电路设计...................................................................................................175.1典型应用电路.............................................................................................175.2双电源音频功率放大器原理图.................................................................175.3双电源音频功率放大器PCB图................................................................18第六章电路制作与调试.......................................................................................196.1利用PCB制作电路板................................................................................196.2装配与调试.................................................................................................19第七章电路图的绘制与制板中应注意的问题...................................................207.1Sch原理图应注意常见问题.......................................................................207.2PCB设计中应注意的问题..........................................................................217.3焊盘应注意的常见问题.............................................................................22总结..............................................