Power MOSFET Basic and Application解析

4.9功率型MOSFET用作开关(THE POWER MOSFET USED AS A SWITCH)4.9.1概论(Introduction)虽然场效应电晶体(field-effect transistor FET)应用于电路设计上己有许多年了，而近年来功率型金属氧化半导体场效应电晶体(metal-oxide-semiconductor field-effect transistor MOSFET)，也己成功地制造出来，并在商业上大量的应用于功率电子的设计上。

而此MOSFET的功能需求，更超越了其它的功率组件，工作频率可达20kHz以上，一般都工作于100-200kHz，而不需像双极式功率电晶体有诸般经验上的限制。

当然，如果我们设计转换器工作于100 kHz频率下，比工作于20kHz的频率会有更多的优点，最重要的优点就是能减少体积大小与重量，功率型MOSFET提供设计者一种高速度，高功率，高电压，与高增益的组件，且几乎没有储存时间，没有热跑脱与被抑制的崩溃特性，由于不同的制造厂商会使用不同的技术来制造功率型的FET，因此就会有不同的名称，如HEXFET，VMOS，TMOS 等，此乃成为每一公司特有的注册商标。

虽然结构上会有所改变而增强了某些功能，但是所有的MOSFETs基本的工作原理都是相同的，事实上对某些应用上来说，使用特有型式的MOSFET有时亦会较使用其它型式来得适切引人些。

4.9.2基本MOSFET的定义(Basic MOSFET Definitions)MOSFET的电路符号示于图4-16中，此为N通道的MOSFET，在图4-16中另一个为NPN双极式电晶体，可互相参考比较其符号之不同，当然亦有P通道的MOSFET，其电路符号中的箭头方向刚好与N通道相反，在图4-16的这二个电路符号，双极式电晶体的集极，基极，与射极端，就相对于MOSFET的漏极，栅极与源极端。

虽然此二者组件都称为电晶体，可是我们必须明了，双极式组件与MOSFET，在结构上与操作原理上还是有明显的不同。

Power MOSFET♦ 内容MOSFET类型 功率MOSFET内部结构 MOSFET工作原理 MOSFET重要参数 MOSFET驱动电路 MOSFET功耗及选择 DC/DC的MOSFET选择和 PCB布板 MOSFET工艺和生产流程 DrainGate Source Drain GateSourceCircuit SymbolPackage Pin LayoutPower MOSFET♦ 什么是MOSFET，定义MOSFET ♦ Metal - Oxide – Semiconductor Field Effect Transistor ♦ MOSFET is a three-terminal devices which in basic term behaves as a voltage controlled switchDrainGate Source Drain GateSourceCircuit SymbolPackage Pin LayoutPower MOSFET♦ 氧化层：形成门极，由多晶硅代替 氧化层：形成门极， ♦ 氧化隔离层：防止电流在门极和其它两个电极间D、S极流动，但并不阻 氧化隔离层： 极流动， 断电场 ♦ 半导体层：依赖于门极电压，阻断或允许电流在漏极D和源极S间流动 半导体层：依赖于门极电压，Power MOSFET♦ MOSFET类型 Metal Oxide Semiconductor Field Effect Transistor按导电沟道可分为： 按导电沟道可分为：P沟道和N沟道 按栅极电压幅值可分为： 按栅极电压幅值可分为： 栅极电压为零时， 耗尽型--栅极电压为零时，漏源极之间就存在导电沟道 沟道器件，栅极电压大于（小于） 增强型--对于N（P）沟道器件，栅极电压大于（小于）零时才存在导电沟道 功率MOSFET主要是N沟道增强型1Power MOSFET♦ MOSFET内部结构横向导电(信号MOSFET）/垂直导电（功率MOSFET） 垂直导电：平面型和沟槽型Trench(U型沟槽和V型沟槽） 不同厂商制造的功率MOSFET有不同的命名：HEXFET (IR)、VMOS (Phillips)、 SIPMOS (Siemens)，但都是通过将大量物理单元扩散到外延硅基板形成并联结 构的方法制成 功 率 MOSFET 为 多 单 元 集 成 结 构 ， 如 IR 的 HEXFET 采 用 六 边 形 单 元 ； 西 门 子 Siemens的SIPMOSFET采用正方形单元；摩托罗拉公司Motorola的TMOS采用矩形 单元按品字形排列 横向导电:平面型 垂直导电:V型沟槽 垂直导电:平面型 垂直导电:U型沟槽Power MOSFET♦ 平面型MOSFET 没有充分应用芯片的尺寸， 没有充分应用芯片的尺寸，电流和电压额定值有限 适合低压应用，如微处理器，运放，数字电路 适合低压应用，如微处理器，运放， 低的电容， 低的电容，快的开关速度增加或减少门极电压会增大或减少N沟道的大小，以此来控制器件导通 沟道的大小， VddLoadDDriverG S沟道Power MOSFET♦ 垂直导电型MOSFET平面型：具有垂直导电双扩散 MOS 结构的 VDMOSFET Vertical Double-diffused MOSFET ，多个单元结构。

the power mosfet 应用手册The Power MOSFET Application ManualIntroductionThe Power MOSFET Application Manual is a comprehensive guide that delves into the various applications and uses of Power MOSFETs. This manual aims to provide engineers, designers, and enthusiasts with an in-depth understanding of Power MOSFETs, their characteristics, and how they can be effectively implemented in different electronic systems.Section 1: Understanding Power MOSFETs1.1 What is a Power MOSFET?Power MOSFETs, or Metal-Oxide-Semiconductor Field-Effect Transistors, are electronic devices that offer high efficiency, fast switching speeds, and excellent power handling capabilities. This section delves into the structure and functioning of Power MOSFETs, explaining how they differ from their bipolar transistor counterparts.1.2 MOSFET Characteristics and SpecificationsThis subsection explores the various specifications and characteristics of Power MOSFETs, including voltage ratings, current ratings, on-resistance, gate charge, and thermal considerations. It provides engineers with the necessary knowledge to select the appropriate MOSFETs for different applications.Section 2: Power MOSFET Applications2.1 Switching ApplicationsPower MOSFETs have found extensive use in switching applications, such as motor drives, power supplies, and inverters. This section highlights the advantages of using Power MOSFETs in these applications and provides guidelines for circuit design, gate drive requirements, and considerations for minimizing power losses.2.2 Audio AmplificationPower MOSFETs are also commonly used in audio amplifiers due to their low distortion and high power capabilities. This subsection discusses the design considerations for audio amplifiers, including load matching, biasing, and output protection. It provides engineers with the necessary information to design efficient and high-quality audio amplifiers.2.3 Lighting ApplicationsPower MOSFETs are vital components in various lighting applications, including LED drivers, automotive lighting, and streetlights. This section explores the key considerations for designing lighting circuits using Power MOSFETs, including thermal management, dimming techniques, and EMI suppression.2.4 Power SuppliesPower MOSFETs play a crucial role in power supply designs, offering high efficiency and compact size. This subsection discusses the use of Power MOSFETs in different power supply topologies, such as buck converters, boost converters, and flyback converters. It also addresses the challenges ofdesigning power supplies with Power MOSFETs and provides guidelines for achieving optimal performance.Section 3: Protection and Reliability3.1 Overcurrent and Overvoltage ProtectionTo ensure the reliable operation of circuits using Power MOSFETs, adequate protection mechanisms must be implemented. This section covers the different protection techniques, such as overcurrent and overvoltage protection circuits, along with their advantages and limitations.3.2 Thermal ManagementProper thermal management is essential for preventing Power MOSFETs from overheating and ensuring their longevity. This subsection discusses the thermal behavior of Power MOSFETs and presents various cooling techniques, such as heatsinks, thermal vias, and thermal pads, to efficiently dissipate heat.3.3 ESD ProtectionElectrostatic Discharge (ESD) can pose a significant threat to Power MOSFETs and other sensitive electronic components. This section provides an overview of ESD protection methods and highlights the importance of implementing proper ESD protection measures in Power MOSFET applications.ConclusionThe Power MOSFET Application Manual aims to equip engineers, designers, and enthusiasts with the knowledge and skills necessary toeffectively utilize Power MOSFETs in their electronic designs. By providing insights into the characteristics, applications, and protection considerations, this manual serves as a valuable resource for those looking to optimize the performance and reliability of their circuits.。

NCE N-Channel Enhancement Mode Power MOSFETDescriptionThe NCE40H21 uses advanced trench technology and design to provide excellent R DS(ON) with low gate charge. It can be used in a wide variety of applications.General Features● V DS =40V ,I D =210AR DS(ON) < 3.2m Ω @ V GS =10V● High density cell design for ultra low Rdson ● Fully characterized avalanche voltage and current ● Good stability and uniformity with high E AS ● Excellent package for good heat dissipation ● Special process technology for high ESD capabilityApplication● Power switching application● Hard switched and high frequency circuits ● Uninterruptible power supply100% UIS TESTED!100% ∆Vds TESTED!Schematic diagramMarking and pin assignmentTO-220-3L top viewPackage Marking and Ordering InformationDevice MarkingDeviceDevice PackageReel SizeTape widthQuantityNCE40H21 NCE40H21 TO-220-3L-- -Absolute Maximum Ratings (T A =25℃unless otherwise noted)Parameter Symbol Limit UnitDrain-Source Voltage V DS 40 V Gate-Source Voltage V GS ±20 V Drain Current-ContinuousI D 210 ADrain Current-Continuous(T C =100℃) I D (100℃) 148 A Pulsed Drain Current I DM 840 A Maximum Power Dissipation P D 310 W Derating factor2.07 W/℃Single pulse avalanche energy (Note 5)E AS 2500mJ Operating Junction and Storage Temperature RangeT J ,T STG-55 To 175℃Thermal CharacteristicThermal Resistance,Junction-to-Case (Note 2)R θJC0.48/W ℃Electrical Characteristics (T A =25℃unless otherwise noted)ParameterSymbolCondition Min Typ Max UnitOff CharacteristicsDrain-Source Breakdown Voltage BV DSS V GS =0V I D =250μA 40 - V Zero Gate Voltage Drain Current I DSS V DS =40V,V GS =0V -- 1 μA Gate-Body Leakage Current I GSS V GS =±20V,V DS =0V - - ±100 nA On Characteristics (Note 3) Gate Threshold VoltageV GS(th) V DS =V GS ,I D =250μA 1.3 1.8 2.5 V Drain-Source On-State Resistance R DS(ON) V GS =10V, I D =20A - 2.3 3.2 m ΩForward Transconductance g FSV DS =5V,I D =20A -100 - S Dynamic Characteristics (Note4) Input Capacitance C lss - 10331 - PFOutput CapacitanceC oss - 1160 - PFReverse Transfer Capacitance C rssV DS =25V,V GS =0V,F=1.0MHz- 1045 - PF Switching Characteristics (Note 4) Turn-on Delay Time t d(on) - 41 - nSTurn-on Rise Time t r - 40 - nS Turn-Off Delay Time t d(off) - 145 - nSTurn-Off Fall Time t fV DD =30V,R L =15Ω, R G =2.5Ω,V GS =10V - 65 - nSTotal Gate Charge Q g - 239 - nC Gate-Source Charge Q gs - 23.5 - nCGate-Drain ChargeQ gd I D =20A,V DD =20V,V GS =10V - 49.6 -nCDrain-Source Diode Characteristics Diode Forward Voltage (Note 3) V SDV GS =0V,I S =20A -0.85 1.2 V Diode Forward Current (Note 2)I S - - 210 A Reverse Recovery Time t rr - 55 nS Reverse Recovery Charge Qrr T J = 25°C, I F = 20Adi/dt = 100A/μs(Note3)- 90nCForward Turn-On Timet onIntrinsic turn-on time is negligible (turn-on is dominated by LS+LD)Notes:1. Repetitive Rating: Pulse width limited by maximum junction temperature.2. Surface Mounted on FR4 Board, t ≤ 10 sec.3. Pulse Test: Pulse Width ≤ 300μs, Duty Cycle ≤ 2%.4. Guaranteed by design, not subject to production5. EAS condition ：Tj=25℃,V DD =20V,V G =10V,L=0.5mH,Rg=25ΩNCE40H21 Test circuit1）E AS test Circuits2）Gate charge test Circuit:3）Switch Time Test Circuit：Typical Electrical and Thermal Characteristics (Curves)Vds Drain-Source Voltage (V)Figure 1 Output CharacteristicsVgs Gate-Source Voltage (V)Figure 2 Transfer CharacteristicsI D- Drain Current (A)Figure 3 Rdson- Drain CurrentT J-Junction Temperature(℃)Figure 4 Rdson-JunctionTemperatureQg Gate Charge (nC)Figure 5 Gate ChargeVsd Source-Drain Voltage (V)Figure 6 Source- Drain Diode Forward RdsonOn-Resistance(mΩ)ID-DrainCurrent(A)ID-DrainCurrent(A)NormalizedOn-ResistanceVgsGate-SourceVoltage(V)Is-ReverseDrainCurrent(A)Vds Drain-Source Voltage (V)Figure 7 Capacitance vs VdsVds Drain-Source Voltage (V)Figure 8 Safe Operation AreaT J -Junction Temperature(℃)Figure 9 Power De-ratingT J -Junction Temperature(℃)Figure 10 Current De-ratingI D - D r a i n C u r r e n t (A )C C a p a c i t a n c e (p F )Square Wave Pluse Duration (sec)Figure 11 Normalized Maximum Transient Thermal Impedancer (t ),N o r m a l i z e d E f f e c t i v e T r a n s i e n t T h e r m a l I m p e d a n c eP o w e r D i s s i p a t i o n (W )I D - D r a i n C u r r e n t (A )TO-220-3L Package InformationDimensions In Millimeters Dimensions In Inches SymbolMin.Max.Min.Max.A 4.400 4.600 0.173 0.181A1 2.250 2.550 0.089 0.100b 0.710 0.910 0.028 0.036b1 1.170 1.370 0.046 0.054c 0.330 0.650 0.013 0.026c1 1.200 1.400 0.047 0.055D 9.910 10.250 0.390 0.404E 8.9500 9.750 0.352 0.384E1 12.650 12.950 0.498 0.510e 2.540 TYP. 0.100 TYP.e1 4.980 5.180 0.196 0.204F 2.650 2.950 0.104 0.116H 7.900 8.100 0.311 0.319h 0.000 0.300 0.000 0.01213.400 0.508 0.528L 12.900L1 2.850 3.250 0.112 0.128 V 7.500 REF. 0.295 REF.Φ 3.400 3.800 0.134 0.150Attention:■Any and all NCE power products described or contained herein do not have specifications that can handle applications that require extremely high levels of reliability, such as life-support systems, aircraft's control systems, or other applications whose failure can be reasonably expected to result in serious physical and/or material damage. Consult with your NCE power representative nearest you before using any NCE power products described or contained herein in such applications.■ NCE power assumes no responsibility for equipment failures that result from using products at values that exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or other parameters) listed in products specifications of any and all NCE power products described or contained herein.■Specifications of any and all NCE power products described or contained herein stipulate the performance, characteristics, and functions of the described products in the independent state, and are not guarantees of the performance, characteristics, and functions of the described products as mounted in the customer’s products or equipment. To verify symptoms and states that cannot be evaluated in an independent device, the customer should always evaluate and test devices mounted in the customer’s products or equipment.■ NCE power Semiconductor CO.,LTD. strives to supply high-quality high-reliability products. However, any and all semiconductor products fail with some probability. It is possible that these probabilistic failures could give rise to accidents or events that could endanger human lives, that could give rise to smoke or fire, or that could cause damage to other property. When designing equipment, adopt safety measures so that these kinds of accidents or events cannot occur. Such measures include but are not limited to protective circuits and error prevention circuits for safe design, redundant design, and structural design.■ In the event that any or all NCE power products(including technical data, services) described or contained herein are controlled under any of applicable local export control laws and regulations, such products must not be exported without obtaining the export license from the authorities concerned in accordance with the above law.■No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying and recording, or any information storage or retrieval system, or otherwise, without the prior written permission of NCE power Semiconductor CO.,LTD.■Information (including circuit diagrams and circuit parameters) herein is for example only ; it is not guaranteed for volume production. NCE power believes information herein is accurate and reliable, but no guarantees are made or implied regarding its use or any infringements of intellectual property rights or other rights of third parties.■ Any and all information described or contained herein are subject to change without notice due to product/technology improvement, etc. When designing equipment, refer to the "Delivery Specification" for the NCE power product that you intend to use.■This catalog provides information as of Sep.2010. Specifications and information herein are subject to change without notice.。

MOS场效应管简介及原理（英文）【简介】MOS场效应晶体管（Metal-Oxide-Semiconductor Field-Effect Transistor）是一种常用于电子电路的晶体管。

它是一种小型、高度集成的设备，能够控制通过它的电流流动。

MOSFET被广泛应用于数字和模拟电子学、通信系统和电力电子等领域。

【原理】MOSFET的基本工作原理是通过在栅极电极施加电压来控制通过源极和漏极的电导。

通过栅极施加的电压决定了通过MOSFET的电流量。

MOSFET有两种类型：N型（负型）和P型（正型）。

N 型MOSFET的基板材料为n型半导体材料（含电子），而P 型MOSFET的基板材料为p型半导体材料（含空穴）。

这些材料的选择取决于应用，因为它们具有不同的电气特性。

MOSFET在电子电路中广泛应用，因为它们具有小型化、高速度和低功耗等优点。

它们还可以使用现代半导体制造技术轻松制造，使其成本效益高，并且广泛可用。

【英文】MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) is a type of transistor commonly used in electronic circuits. It is a small, highly integrated device that can control the flow of electrical current through it. MOSFETs are used in awide range of applications, including digital and analog electronics, communication systems, and power electronics.The basic principle of operation of a MOSFET is that it controls the flow of electrical current through the gate electrode, which is insulated from the source and drain by a thin oxide layer. When a voltage is applied to the gate electrode, a current flows through the channel between the source and drain, causing the MOSFET to conduct electricity. The voltage applied to the gate electrode determines the amount of current that flows through the MOSFET.There are two main types of MOSFETs: N-type (for negative) and P-type (for positive). N-type MOSFETs have an n-type semiconductor material (containing electrons) as the substrate, while P-type MOSFETs have a p-type semiconductor material (containing holes) as the substrate. These types of materials are chosen based on the application, as they have different electrical properties.MOSFETs are widely used in electronic circuits because of their small size, high speed, and low power consumption. They are also easy to fabricate using modern semiconductor manufacturing techniques, making them cost-effective and widely available.。

Power MOSFET中文是电力场效应晶体管的意思。

电力场效应晶体管分为两种类型，结型和绝缘栅型，但通常所说的是绝缘栅型中的MOS型（Metal Oxide Semiconductor FET），简称电力MOSFET（Power MOSFET）。

P-MOSFET是用栅极电压来控制漏极电流，它的显著特点是驱动电路简单，驱动功率小，开关速度快，工作频率高；但是其电流容量小，耐压低，只用于小功率的电力电子装置，其工作原理与普通MOSFET一样。

特性Power MOSFET的主要特性如下：Power MOSFET静态特性主要指输出特性和转移特性, 与静态特性对应的主要参数有：漏极击穿电压；漏极额定电压；漏极额定电流和栅极开启电压等。

1、静态特性(1) 输出特性即是漏极的伏安特性曲线，如图2(b)所示.由图所见,输出特性分为截止，饱和与非饱和3个区域，这里饱和、非饱和的概念与GTR 不同。

饱和是指漏极电流ID 不随漏源电压UDS的增加而增加，也就是基本保持不变；非饱和是指地UCS一定时，ID 随UDS 增加呈线性关系变化.(2) 转移特性表示漏极电流ID与栅源之间电压UGS的转移特性关系曲线, 如图2(a) 所示. 转移特性可表示出器件的放大能力, 并且是与GTR 中的电流增益β相似。

由于Power MOSFET是压控器件，因此用跨导这一参数来表示，跨导定义为(1) 图中UT 为开启电压，只有当UGS=UT时才会出现导电沟道，产生漏极电流ID。

2、动态特性动态特性主要描述输入量与输出量之间的时间关系，它影响器件的开关过程。

由于该器件为单极型，靠多数载流子导电，因此开关速度快，时间短，一般在纳秒数量级。

Power MOSFET的动态特性.如图所示。

Power MOSFET栅极电阻；RL为漏极负载电阻；RF用以检测漏极电流。

Power MOSFET的开关过程波形，如图3(b)所示。

Power MOSFET的开通过程；由于Power MOSFET有输入电容，因此当脉冲电压up的上升沿到来时，输入电容有一个充电过程,栅极电压uGS 按指数曲线上升.当uGS 上升到开启电压UT 时,开始形成导电沟道并出现漏极电流iD.从up 前沿时刻到uGS=UT,且开始出现iD 的时刻,这段时间称为开通延时时间td(on).此后,iD 随uGS 的上升而上升,uGS 从开启电压UT 上升到Power MOSFET临近饱和区的栅极电压uGSP 这段时间,称为上升时间tr.这样Power MOSFET的开通时间ton=td(on)+tr(2)Power MOSFET 的关断过程:当up 信号电压下降到0 时,栅极输入电容上储存的电荷通过电阻RS 和RG 放电,使栅极电压按指数曲线下降,当下降到uGSP 继续下降,iD 才开始减小,这段时间称为关断延时时间td(off).此后,输入电容继续放电,uGS 继续下降,iD 也继续下降,到uGS<u< span="" style="margin: 0px; padding: 0px; list-style-type: none;">T 时导电沟道消失,iD=0, 这段时间称为下降时间tf.这样Power MOSFET 的关断时间toff=td(off)+tf (3)从上述分析可知,要提高器件的开关速度,则必须减小开关时间.在输入电容一定的情况下,可以通过降低驱动电路的内阻RS 来加快开关速度. 电力场效应管晶体管是压控器件,在静态时几乎不输入电流.但在开关过程中,需要对输入电容进行充放电,故仍需要一定的驱动功率.工作速度越快,需要的驱动功率越大。

电力电子课程设计直流斩波电路的设计系、部：电气与信息工程学院学生姓名：刘宗泉指导教师：肖文英职称副教授专业：自动化班级： 1102 班完成时间： 2014年5月28日摘要直流斩波电路（DC Chopper）的功能是将直流电变为另一固定电压或可调电压的直流电，也称为直接直流-直流变换器（DC/DC Converter）。

直流斩波电路一般是指直接将直流电变为另一直流电的情况，不包括直流-交流-直流的情况。

习惯上，DC-DC变换器包括以上两种情况。

直流斩波电路的种类较多，包括6种基本斩波电路：降压斩波电路，升压斩波电路，升降压斩波电路，Cuk斩波电路，Sepic斩波电路和Zeta斩波电路，其中前两种是最基本的电路。

一方面，这两种电路应用最为广泛，另一方面，理解了这两种电路可为理解其他的电路打下基础。

利用不同的基本斩波电路进行组合，可构成复合斩波电路，如电流可逆斩波电路、桥式可逆斩波电路等。

利用相同结构的基本斩波电路进行组合，可构成多相多重斩波电路。

直流斩波电路广泛应用于直流传动和开关电源领域，是电力电子领域的热点。

全控型器件绝缘栅双极晶体管（Insulated-Gate Bipolar,IGBT）综合了电力晶体管（Giant Transistor,GTR）和电力场效应管（Power Field Effect,MOSFET）的优点，具有良好的特性。

目前已取代了原来GTR和一部分电力MOSFET的市场，应用领域迅速扩展，成为中小功率电力电子设备的主导器件。

本课程设计使用全控型器件IGBT做降压斩波电路控制器件；SG3525作为控制芯片，EXB841作为驱动芯片讨论降压斩波主电路、控制电路、驱动电路和保护电路的原理与设计。

关键词：IGBT；降压斩波电路；SG3525；EXB841ABSTRACTDC Chopper circuit (DC Chopper) is the function of the direct current (DC) to a fixed voltage or adjustable voltage direct current (DC), also known as direct dc-dc Converter (DC/DC Converter). Generally refers to the dc chopper circuit directly to the direct current into another, does not include dc - ac - dc.Traditionally, DC - DC converter includes the above two cases.Dc chopper circuit sort is more, including six basic chopper circuit: buck chopper circuit, boost chopper circuit, buck chopper circuit, Cuk chopper circuit, Sepic chopper circuit and Zeta chopper circuit, including the first two are the most basic circuit. On the one hand, the most widely used two kinds of circuit, on the other hand, to understand these two circuits can lay the foundation to understand the other circuit.Are combined with different basic chopper circuit, can constitute a composite chopper circuit, such as current reversible chopper circuit, bridge type reversible chopper circuit, etc. Using basic chopper circuit on the structure of the same combination, can constitute a heterogeneous multiple chopper circuit.Dc chopper circuit is widely used in dc transmission and switching power supply, is a hotspot in the field of power electronics. All control type device select insulated gate bipolar transistor (IGBT) integrated the advantages of GTR and power MOSFET, has the good properties. Has replaced the original GTR and part of the power MOSFET market, rapidly expanding application areas, the small and medium-sized power power electronics equipment has become the dominant device.Therefore, the curriculum design topic is: the design using the control device for IGBT buck chopper circuit. Mainly discuss buck chopper main circuit, control circuit sg3525, drive circuit exb841 and protect circuit principle and design.Key words igbt；buck chopper；sg3525；exb841目录1 设计要求与方案 (1)1.1 设计要求 (1)1.1.1 课程设计目的 (1)1.1.2 课程设计要求 (1)1.2 方案确定 (1)2 降压斩波主电路设计 (3)2.1 BUCK电路工作原理 (3)2.2 主电路参数分析 (4)3 控制电路原理与设计 (6)3.1 控制电路方案选择 (6)3.2 控制电路工作原理 (7)4 驱动电路原理与设计 (8)4.1 驱动电路方案选择 (8)4.2 驱动电路分析与设计 (9)5 保护电路的原理与设计 (10)5.1 过电压保护 (10)5.2 过电流保护 (11)6 电路仿真 (13)设计心得 (19)参考文献 (20)致谢 (21)附录A (22)附录B (23)1 设计要求与方案1.1 设计要求1.1.1 课程设计目的（1）培养文献检索的能力，特别是如何利用Internet检索需要的文献资料。

摘要开关电源是应用于广泛领域的一种电力电子装置。

它具有电能转换效率高、体积小、重量轻、控制精度高和快速性好等优点，在小功率范围内基本取代了线性电源，并迅速想大功率范围推进，在很大程度上取代了晶闸管相控整流电源。

可以说，开关电源技术是目前中小功率直流电能变换装置的主流技术。

本文首先描述了开关电源的发展，对目前出现的几种典型的开关电源技术作了归纳总结和分析比较，在此基础上指出了开关电源技术的发展状况和开关电源产品的发展趋势。

并且对开关电源的发展史、应用范围、主电路的选择、控制方法作了简要的介绍。

在设计中主要采用了脉宽调制（PWM）、全桥整流、自锁保护等技术，应用了控制芯片UC3842做为PWM控制芯片，对变压器次级线圈采用堆叠式绕法，改进光耦反馈电路的选择，使电路能达到所需基本要求同时，力求稳定、高效。

关键字：开关电源，拓扑结构，变压器，正激式AbstractThe switch power supply is a kind of electric power electronics which applies in the extensive realm to be used.It has an electric power conversion's efficiency high, the physical volume is small, the weight is light, the control accuracy is high with fast etc. advantage, within the scope of small power replaced line power supply, and in high-power scope propulsion quickly, to a large extent,it replaced the thyristor phase - controlled rectifying power supply.We can say, the switch power supply technique is the essential technique which wins small electric power transformation of the power direct current to equip currently.This text described the development of switch power supply first, to a few kinds which appear currently typical model of the switch power supply technique made to induce summary and analysis comparison, pointing out the development trend of the technical development condition of the switch power supply and switch power supply product on this foundation.And introduce the switch power supply’s phylogeny,application, main electric circuit of power supply and controled a method. The design adopted PWM, the whole bridgeses commutated, lock protection etc. technique, applied control the chip UC3842 to be used as PWM control chip, the transformer adoprt adopt pile circle, improve the choice of the electric circuit, make the electric circuit be able to attain need basic request in the meantime, try hard for stability, efficiently.Key words：Switch power supply，topology，transform，Forward目录摘要 (I)Abstract ............................................................................................................................................ I I 目录 .. (III)1 绪论 (1)1.1 引言 (1)1.2 开关电源的发展历史 (1)1.2.1 国外发展历史 (1)1.2.2 国内发展状况 (2)1.3 目前需要克服的困难 (2)1.4 开关电源的发展趋势 (3)1.5 本文的设计要求 (4)2 开关电源的工作原理 (6)2.1 开关电源的基本构成 (6)2.2 开关电源常用的拓扑结构分析 (6)2.2.1 降压型 (6)2.2.2 升压型 (7)2.2.3 升降压型 (8)2.2.4 反激式 (9)2.2.5 正激式 (11)2.2.6 推挽式 (12)2.3 拓扑结构的确定 (13)3. 基于UC3842的开关电源的设计与实现 (14)3.1 开关电源电路的设计 (14)3.1.1 开关电源电路的总体简介 (14)3.1.2 基于UC3842的基本结构 (14)3.1.3 各部分功能简介 (14)3.2 UC3842芯片简介 (15)3.2.1 UC3842的特点 (15)3.2.2内部结构和引脚图 (16)3.2.3 引脚功能 (16)3.2.4 芯片工作原理 (17)3.3 各部分回路设计 (18)3.3.1 主回路的设计 (18)3.3.2 控制保护回路的设计 (21)3.3.3 反馈电路的设计 (23)3.4 外围主要器件的选取 (23)4. 开关电源变压器的设计 (28)4.1 与变压器相关的一些基本概念 (28)4.2 变压器用料介绍 (30)4.3 高频变压器的设计 (32)4.4 变压器的绕制方法 (35)结论 (38)致谢 (39)参考文献 (40)附录总原理图 (41)1 绪论1.1 引言电子技术的高速发展，电子设备与人们的工作、生活的关系日益密切，而电子设备都离不开可靠的电源，进入 90 年代开关电源相继进入各种电子、电器设备领域，程控交换机、通讯、电力检测设备电源、控制设备电源等都已广泛地使用了开关电源，更促进了开关电源技术的迅速发展。

英文回答：Complementarity MOSFET has a significant role to play inplementarity as a device consisting of MoSFET on the n—path and MoSFET on the p—path. MOSFET and MOSFET are considered to be basicponents of theplementary MOSFET, where the main stream of the n ditch is electron, while the main stream of the p ditch is empty. The excellentplementarities of theplementary MOSFET extended its use in digital and analog circuits and demonstrated great potential in the areas of power amplifiers, power switches and simulation switches. The development of this technology is closely linked to the development of the national electronics industry and is important for achieving national ownership of the electronics industry.互补型MOSFET作为一种由n沟道MOSFET和p沟道MOSFET组成的器件，在互补对中具有显著的作用。

n沟道MOSFET和p沟道MOSFET被视作互补型MOSFET的基本构成单元，其中n沟道MOSFET的主导载流子为电子，而p沟道MOSFET的主导载流子为空穴。

AN2626Application note MOSFET body diode recovery mechanism in a phase-shiftedZVS full bridge DC/DC converterIntroductionThe ZVS exploits the parasitic circuit elements to guarantee zero voltage across theswitching device before turn on, eliminating hence any power losses due to thesimultaneous overlap of switch current and voltage at each transition [1].In order to allow the ZVS condition, the intrinsic body diode of the MOSFET has to conduct;in no or low load operation the extremely low reverse voltage, could be not sufficient toguarantee the reverse recovery charge sweep out before turning off the MOSFET. Hence,the body diode could be stressed by high dv/dt that latching the parasitic internal bipolartransistor brings the MOSFET to the failure.In the market of power applications like telecom power supply, main frame computer-server,welding and steel cutting, the demand of power density is growing each year. Increasingpower density means reducing component counts, power losses, heat-sink and reactivecomponent size. The alternative to the hard switched full bridge, typical topology for theseapplications, was the phase-shifted zero voltage switching (ZVS) full bridge. This ZVStechnique guarantees zero voltage across the switching device before turn on, eliminatinghence any power losses due to the simultaneous overlap of switch current and voltage ateach transition.By this switching technique also at high frequencies, the switching losses are low; hence itallows the reduction of the components reactive size only. Obviously, by having lower losseslower heat-sink size is allowed. Furthermore, by avoiding the hard-switching condition theEMI/RFI noise is reduced.The zero voltage condition occurs by the intrinsic MOSFET body diode conduction; anextremely low reverse voltage, occurring at no or low load operation, which could be notsufficient to guarantee the reverse recovery charge sweep out before turning off theMOSFET. In this condition high dv/dt values could turn on the intrinsic bipolar and destroythe MOSFET.The deep studies of these failure mechanisms have led STMicroelectronics to design newtechnology in order to develop MOSFETs really suitable for high power phase-shifted ZVSapplications. In this technical note we will investigate the possible triggering on of theinternal parasitic bipolar.September 2007Rev 1 1/13Contents AN2626 Contents1Topology description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2MOSFET body diode recovery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 3Observations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 4References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 5Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122/13AN2626List of figures List of figuresFigure 1.Phase-shifted ZVS full bridge circuit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Figure 2.Switching sequence in a P-S ZVS FB converter DC/DC . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Figure 3.Typical waveforms in a P-S ZVS FB converter DC/DC . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Figure 4.Current flow into the parallel body diode-channel MOSFET . . . . . . . . . . . . . . . . . . . . . . . . 7 Figure 5.Current flow into the parallel body diode-channel MOSFET. . . . . . . . . . . . . . . . . . . . . . . . . 8 Figure 6.Current flow into the channel MOSFET (first quadrant) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Figure 7.Current flow due to the reverse recovery of the body diode . . . . . . . . . . . . . . . . . . . . . . . . 9 Figure parison between standard and fast diode technology. . . . . . . . . . . . . . . . . . . . . . . . . 10 Figure 9. A typical leading leg MOSFET waveforms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Figure 10. A typical lagging leg MOSFET waveforms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113/13Topology description AN26264/131 Topology descriptionThe basic circuit of the phase-shifted converter is composed by four switches; two for each"leg".The switches, labeled Q1 through Q4 in the Figure 1 are shunted by their intrinsic bodydiode (D1 through D4) and intrinsic output capacitance (C1 through C4), shown separatelyin order to clarify their role in the global functioning.Figure 1.Phase-shifted ZVS full bridge circuitAN2626Topology description5/13●Transition t 0-t 1From the Figure 3, at t 0 Q1 and Q3 are in on state and on the primary side there is anenergy equal to:Equation 1Instantly, at t 0 the switch Q1 is turned off and the resonant transition begins. The primarycurrent continues to flow, with a like-linear shape (since the current is forced by the outputinductor) using the charge stored in the switch output capacitance C2. Simultaneously, theprimary current will charge the output capacitance C1 of Q1 from essentially 0 V to thesupply voltage V dd , and will discharge the output capacitance C2 from V dd to zero. Thetransition finishes when the Q2 source voltage exceeds the Q2 drain voltage sufficiently todirectly bias the internal body diode D2.●Freewheeling t 1-t 2Now D3 is directly biased and the output inductor freewheels. The voltage across the switchQ2 is equal to the drop on its internal body diode D2 hence the ZVS condition is verified.The switch Q3 is turned on and the current, flowing through the primary side, now is sharedbetween the body diode D2 and the channel of MOSFET Q2. During the freewheeling stateboth output rectifier diodes are forward biased, and hence the reflected voltage to theprimary is null.●2-t 4The switch Q3 is turned off, the energy available to complete the transition is:Equation 2It is much lower than it was in the lead leg, since the magnetizing and output inductance donot contribute [4]. For this reason it is easier to miss the ZVS condition. If the energy storedE t 0t 1–E mag E output reflected ––12--L leak L res +()I mag t 0()NI out t 0()+()⋅+=E t 2t 4–12--L leak L res +()I mag t 2()NI out t 2()+()⋅=Topology description AN26266/13is enough, the current will continue to flow into the output capacitances C3 and C4. During the first period the voltage is applied across the leakage and external inductors added in series to the theoretical primary winding of the transformer. The voltage across the theoretical primary winding of the transformer will remain zero, and both output diodes will conduct, until the current flowing through the leakage and external inductors will change direction and reach the reflected output current (t3-t4 period).●Power transfer t4-t5Once the output diode is turned on, the power is transferred from primary to the secondary side of transformer. When the primary current reaches the expected value the circuit is in a condition similar to that reported in the step 1.7/132 MOSFET body diode recoveryThe cross section of a MOSFET device, illustrated in Figure 4, shows an intrinsic diodebetween body and drain, that is the base-collector junction of the "parasitic" a NPN bipolartransistor source-body-drain. In no or low load conditions this transistor could be turned onand hence brings the MOSFET to the failure, by short circuiting drain and source while highinvestigate the freewheeling and the ZVS steps. During step 2 the current freewheels intothe body-drain diode D2 (see Figure 4); since this is directly biased carriers are injected inthe N- epi (holes) and P body (electrons) regions of the device. Once Q2 is turned on, a portion of the total current flows through the channel, the parasitic JFET, and the epi region: the MOSFET is conducting in the third quadrant (see Figure 5). When the transformercurrent changes direction the MOSFET Q3 conducts into the first quadrant (see Figure 6).The internal body diode D2 now is reverse biased; since it is in parallel with the lowresistance channel regions its effective reverse voltage is low. This causes a slow minoritycarriers extraction, especially from the N- region, since the holes have lower mobility thanthe electron one. Obviously at low load operation the current flowing through the channelMOSFET is much lower and so is the drop voltage; in this condition the body diode needsmore time to complete the reverse recovery, but the powering period is very short and couldnot be sufficient to remove the minority carriers in the P-N junction.Figure 4.Current flow into the parallel body diode-channel MOSFET8/13Figure 5.Current flow into the parallel body diode-channel MOSFETWhen the Q2 MOSFET is turned off D2 should have yet completely removed its minority carriers, see from both P+ and N- regions, otherwise the high reverse voltage (due to Q1 turning on) results in a fast removal of these carriers. Minority carriers in the N- region are swept towards the P+ body region and this rapid displacement results in a significant current flowing through the P+ body.Figure 6.Current flow into the channel MOSFET (first quadrant)9/13In normal condition the source and body regions (that is the emitter and the base of theparasitic bipolar) are shorted via upper source metallization, but by flowing a significantcurrent into the body region below the source region (see Figure 7), the intrinsic resistanceof this region (shown as Rb) could divert a sufficient current portion able to trigger on theparasitic bipolar; it means creating a short circuit between drain and source pins thus,destroying the device.Figure 7.Current flow due to the reverse recovery of the body diodeHence, in order to overcome the previous problems, a MOSFET should have somecharacteristics:●The intrinsic body diode with low Trr and low Qrr;●Ruggedness to the stress due to the trigger on of the parasitic bipolar.To meet the need related to the body diode a new technology has been developed. The newFD (fast diode) MOSFET has straightforward advantages in terms of Trr, Qrr, Irm andruggedness in dv/dt.Observations AN262610/13 3 ObservationsChoosing to use fast diode technology MOSFETs is a good choice. STMicroelectronics hasdeveloped the new Fast diode MD mesh generation that shows excellent performance inthese types of topologies. These device families guarantee operation in safe conditions, sofar from the triggering on of the parasitic bipolar, so that they are very suitable for the fullbridge phase-shift ZVS topologies.In order to understand these advantages we have compared a standard MOSFET versus aFD MOSFET.The FD technology device has a lower Qrr than the standard device; meaning that when thediode is reverse biased by the drop voltage on the channel MOSFET, very low in low loadcondition, it will be faster to complete the recovery and so when it will highly reverse biasedby the turn on of the switch in the its same leg it will work in a much more safe condition interm of dv/dt stress (see Figure 8).Figure parison between standard and fast diode technologyAs you can see the ST fast diode technology MOSFET works better, keeping the overallsystem in a more safe condition.Table 1.Measured dynamic electrical parameters of the devices comparedDevice Irm Trr Qrr(Di/Dt=100A µs, Isd=20 A, Vdd=100 V , Tj=25°C)(A)(nS)(µC)Standard STW20NM60253905Fast diodeSTW20NM60FD 16240 1.8AN2626Observations11/13The fast diode device has worked properly in the application and has shown goodperformances; report some pictures related to a 1.5 kW DC/DC converter captured on testbench (Figure 9 and Figure 10).Figure 9. A typical leading leg MOSFET waveformsFigure 10. A typical lagging leg MOSFET waveformsReferences AN262612/134 References1.L. Saro, et al., "High-Voltage MOSFET Behavior in Soft-Switching Converter: Analysisand Reliability Improvements," International Tel-communication Conference, SanFrancisco, 1998.2. Alexander Fiel and Thomas Wu International Rectifier Applications Department ElSegundo, CA 90245, USA "MOSFET Failure Modes in the Zero-Voltage-Switched Full-Bridge Switching Mode Power Supply Applications"3. Sampat Shekhawat, Mark Rinehimer and Bob Brockway Discrete Power Group,Fairchild Semiconductor AN-7536 "FCS Fast Body Diode MOSFET for Phase-ShiftedZVS PWM Full Bridge DC/DC Converter"4.Laszlo Balogh, "Design review:100 W, 400 kHz, DC/DC converter with current doublersynchronous rectification achieves 92% efficiency"5 Revision history Table 2.Document revision history DateRevision Changes21-Sep-20071Initial releaseAN2626Please Read Carefully:Information in this document is provided solely in connection with ST products. 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4.9功率型MOSFET用作开关(THE POWER MOSFET USED AS A SWITCH)4.9.1概论(Introduction)虽然场效应电晶体(field-effect transistor FET)应用于电路设计上己有许多年了，而近年来功率型金属氧化半导体场效应电晶体(metal-oxide-semiconductor field-effect transistor MOSFET)，也己成功地制造出来，并在商业上大量的应用于功率电子的设计上。

而此MOSFET的功能需求，更超越了其它的功率组件，工作频率可达20kHz以上，一般都工作于100-200kHz，而不需像双极式功率电晶体有诸般经验上的限制。

当然，如果我们设计转换器工作于100 kHz频率下，比工作于20kHz 的频率会有更多的优点，最重要的优点就是能减少体积大小与重量，功率型MOSFET提供设计者一种高速度，高功率，高电压，与高增益的组件，且几乎没有储存时间，没有热跑脱与被抑制的崩溃特性，由于不同的制造厂商会使用不同的技术来制造功率型的FET，因此就会有不同的名称，如HEXFET，VMOS，TMOS等，此乃成为每一公司特有的注册商标。

虽然结构上会有所改变而增强了某些功能，但是所有的MOSFETs基本的工作原理都是相同的，事实上对某些应用上来说，使用特有型式的MOSFET有时亦会较使用其它型式来得适切引人些。

4.9.2基本MOSFET的定义(Basic MOSFET Definitions)MOSFET的电路符号示于图4-16中，此为N通道的MOSFET，在图4-16中另一个为NPN双极式电晶体，可互相参考比较其符号之不同，当然亦有P通道的MOSFET，其电路符号中的箭头方向刚好与N通道相反，在图4-16的这二个电路符号，双极式电晶体的集极，基极，与射极端，就相对于MOSFET的漏极，栅极与源极端。

虽然此二者组件都称为电晶体，可是我们必须明了，双极式组件与MOSFET，在结构上与操作原理上还是有明显的不同。

功率MOSFET寿命预测技术研究康锡娥【摘要】Electronic component is the foundation of electronic equipment, which being the basic unit, cannot be further divided. Therefore, to a certain extent, the lifetime of electronic components deter-mines the service life of electronic equipments. Power MOSFET is one of the most widely used varieties in all components, according to the statistics, the power MOSFET is of the highest failure rate of components in electronic equipments, and its main failure form is with performance degradation. Taking MOSFET devices as an example, the use environment, voltage and current of the components are simulated, and at the same time, by keeping doing the tests during the experiment, analyzing the test data, determining the sensitive parameters of the components, and establishing the degradation model mainly with sensitive parameters, the lifetime of components is thus estimated.%电子元器件是电子设备的基础,是不能再进行分割的基本单元,因此电子元器件的寿命在一定程度上决定了电子设备的使用寿命.功率MOSFET是所有元器件中使用最广泛的品种之一,数据统计表明,功率MOSFET 是电子设备中失效率最高的元器件,整个寿命周期以性能退化失效为主.以MOSFET 器件为例,模拟器件的使用环境、电压、电流,同时不断对试验过程中的器件进行测试,通过对测试数据进行分析,确定器件的敏感参数,建立以敏感参数为主的退化模型,从而估算元器件的寿命.【期刊名称】《微处理机》【年(卷),期】2017(038)005【总页数】5页(P4-7,19)【关键词】功率MOSFET;寿命预测;敏感参数;退化模型【作者】康锡娥【作者单位】中国电子科技集团公司第四十七研究所,沈阳110032【正文语种】中文【中图分类】TN3电子元器件是整个电子设备和系统的基础，是不能再进行分割的基本单元，因此其可靠性对系统可靠性影响较大。