毕业论文-小功率开关稳压电源设计

I小功率开关稳压电源设计摘要随着电子设备的飞跃发展，电子系统的心脏——电源也得到了迅速的发展，并对其要求越来越高。开关电源被誉为高效节能电源，它具有稳压范围宽、功率密度比大、重量轻等优点，同时它在开关管上较少的能量损耗，使它与线性电源相比具有较高的效率，最高效率可达90％以上，从而使它在移动便携式设备中得到了广泛的应用，因此开展开关电源项目研究具有重要意义。目前开关电源正向集成化、智能化的方向发展。高度集成、功能强大的单片开关电源代表着当今开关电源发展的主流方向。本论文围绕当前流行的单片开关电源芯片进行了小功率开关电源的研究，设计出一种实用的单路输出精密通用式开关稳压电源，可用作半导体激光器驱动电源中的精密电压源。该设计由五个模块电路构成：输入整流滤波、功率转换电路、高频变换器、输出整流滤波和控制电路。该电源共使用3片集成线路：TOP249Y6端单片开关电源（IC1）、线性光耦合器PC817A(IC2)、可调式精密并联稳压器TL431(IC3)。本论文中对该电源的滤波、整流、反馈、启动及保护电路等分别作了细致的研究工作，并通过反复试验取得了高频变压器设计宝贵经验，掌握了单片开关电源设计的核心技术。关键词：单片开关电源，脉宽调制，高频变压器，纹波IITheDesignofLowPowerSwitchingPowerSupplyAbstractWiththerapiddevelopmentofelectronicequipment,electronicsystemoftheheart-thepowerhasbeenrapiddevelopmentanditsincreasinglyhighdemand.Knownasenergyefficientswitchingpowersupply,ithaswidevoltagerange,powerdensitythanlarge,lightweight,etc.,whileitisswitchitonlessenergyconsumptioncomparedwiththelinearpowersupplywithhighefficiency,maximumefficiencyofmorethan90%,makingitportabledevicesinmobilehasbeenwidelyusedtocarryoutswitchingpowersupplyprojectsthereforeimportanttostudy.Towardthepresentswitchingpowersupplyisintegrated,intelligentdirection;highlyintegrated,powerfulsingleroseonthepoweroftoday'sswitchingpowersupplyrepresentsthemainstreamofdevelopmentdirection.Thispaperfocusonthepopularsingle-chipswitchingpowersupplychipforasmallswitchingpowersupplyofthestudy,designapracticalsingle-outputprecisionuniversalregulatedswitchingpowersupply,laserdiodedrivercanbeusedintheprecisionvoltagesource.Thedesignconsistsoffivemodulescircuits:inputrectifierfilter,powerconversioncircuits,highfrequencyconverters,outputrectifierfilterandcontrolcircuit.Thepowerofintegratedcircuitsusing3:TOP249Y6endchipswitchingpowersupply(IC1);linearoptcouplerPC817A(IC2);adjustableprecisionshuntregulatorTL431(IC3).Thepowersupplyfiltering,rectification,feedback,startingandprotectioncircuitsweremadebycarefulresearchandthroughtrialandobtainedvaluableexperienceindesigninghigh-frequencytransformer;single-chipswitchingpowersupplydesignmasteredthecoretechnology.Keywords:single-chipswitchingpowersupply，PWM，highfrequencytransformer，rippleIII目录第1章前言..................................................................................................................11.1引言....................................................................................................................11.2单片开关电源的发展历史................................................................................11.3单片开关电源的发展趋势和新技术................................................................21.3.1“绿色节能”型开关电源.........................................................................31.3.2模块化的开关电源...................................................................................31.3.3高频化的开关电源.....................................................................................41.3.4智能数字化的单片开关电源.....................................................................41.4开关电源的工作原理和电路基本分类............................................................41.4.1开关稳压电源的基本工作原理.................................................................41.4.2开关电源电路的基本分类.........................................................................61.5本论文设计的意义及内容................................................................................81.5.1设计意义......................................................................................................81.5.2设计要求.....................................................................................................8第2章单片开关电源的工作原理和分类..................................................................92.1单片开关电源的工作原理................................................................................92.2.1单片开关电源的基本工作原理.................................................................92.1.2单片开关电源的工作模式.......................................................................102.1.3单片开关电源的基本反馈电路...............................................................112.2单片开关电源的分类及主要特点..................................................................122.3单片开关电源芯片的性能特点......................................................................132.4TOP249Y的工作原理与应用..........................................................................142.4.1TOP249Y的管脚功能..............................................................................142.4.2TOP249Y的内部结构..............................................................................15第3章方案原理与论证............................................................................................163.1整流滤波电路..................................................................................................163.2高频变压器......................................................................................................163.3开关电源的选用..............................................................................................163.3.1输出电流的选择.......................................................................................173.3.2保护电路...................................................................................................17IV3.4电