什么是米勒钳位？为什么碳化硅MOSFET特别需要米勒钳位？
<p>ad810916537b6430425e3fecb40683b9<br /> </p>
<section>
<section>
<p>推送了“SiC科普小课堂”视频课——《什么是米勒钳位？为什么碳化硅MOSFET特别需要米勒钳位？》后反响热烈，很多朋友留言询问课件资料。今天，我们将这期视频的图文讲义奉上，方便大家更详尽地了解在驱动碳化硅MOSFET时采用米勒钳位功能的必要性。</p>
<p> </p>
<p><img alt="封面图.png" src="https://10229191.s21i.faiusr.com/4/ABUIABAEGAAg68WZuwYogLGRlgIw8xE40gc!700x700.png" /></p>
</section>
</section>
<section>
<section>
<section> </section>
</section>
<p> </p>
<p><strong>01 什么是米勒现象</strong></p>
<p> </p>
<p><strong>- 在桥式电路中，功率器件会发生米勒现象，它是指当一个开关管在开通瞬间，使对管的门极电压出现快速升高的现象。</strong></p>
<p> </p>
<p><strong>- 该现象广泛存在于功率器件中，包括IGBT、Si MOSFET、SiC MOSFET。</strong></p>
<p> </p>
<p><strong>- 原理分析：</strong>当下管Q2保持关闭，在上管Q1开通瞬间，桥臂中点电压快速上升，桥臂中点dv/dt的水平，取决于上管Q1的开通速度。该dv/dt会驱动下管Q2的栅漏间的寄生电容Cgd流过米勒电流Igd；Igd=Cgd*（dv/dt），dv/dt越大，米勒电流Igd越大。</p>
<p> </p>
<p><strong>- 米勒电流Igd（红色线）的路径：Cgd→Rgoff→T4 →负电源轨，产生左负右正的电压。</strong></p>
<p> </p>
<p><strong>- Vgs=Igd*Rgoff+负电源轨，这个电压叠加在功率器件门极，Vgs会被抬高，当门极电压超过Vgsth，将会使Q2出现误开通，从而造成直通现象。</strong></p>
<p> </p>
<section>
<section>
<p><img _width="100%" alt="图片" crossorigin="anonymous" data-fail="0" data-imgfileid="100021590" data-index="3" data-original-style="vertical-align:middle;width:100%;" data-ratio="1.1309297912713472" data-s="300,640" data-src="//10229191.s21i.faiusr.com/95/ABUIABBfGAAg-6qZuwYouMfFxwIwjwQ41AQ.webp" data-type="png" data-w="527" src="https://10229191.s21i.faiusr.com/95/ABUIABBfGAAg-6qZuwYouMfFxwIwjwQ41AQ.webp" /></p>
</section>
</section>
<p> </p>
<p><strong>02 如何反制米勒现象</strong></p>
<p> </p>
<p><strong>- 使用门极电压的负压进行负偏置，使负压足够“负”。</strong></p>
<p> </p>
<p><strong>- 提高器件门极的门槛电压（设计选型时选高Vgsth的器件）。</strong></p>
<p> </p>
<p><strong>- </strong><strong>Rgoff数值减小（Rgoff是米勒现象影响程度的主要贡献者之一，数值越大，米勒现象越糟糕）。</strong></p>
<p> </p>
<p><strong>- 减慢功率器件的开通速度。</strong></p>
<p> </p>
<p><strong>- 使用米勒钳位功能。</strong></p>
<p> </p>
<p> </p>
<p><strong>03 IGBT与SiC MOSFET对于米勒钳位的需求</strong></p>
<p> </p>
<p>以下表格为硅IGBT/ MOSFET和碳化硅MOSFET的具体参数和性能数值对比。</p>
<section>
<section><img _width="100%" alt="图片" crossorigin="anonymous" data-fail="0" data-imgfileid="100021593" data-index="6" data-original-style="vertical-align:middle;width:100%;" data-ratio="0.3416666666666667" data-s="300,640" data-src="//10229191.s21i.faiusr.com/95/ABUIABBfGAAg-qqZuwYomPO2lwIwuAg48QI.webp" data-type="jpeg" data-w="1080" src="https://10229191.s21i.faiusr.com/95/ABUIABBfGAAg-qqZuwYomPO2lwIwuAg48QI.webp" /></section>
</section>
<section>
<section><img _width="100%" alt="图片" crossorigin="anonymous" data-fail="0" data-imgfileid="100021594" data-index="7" data-original-style="vertical-align:middle;width:100%;" data-ratio="0.40185185185185185" data-s="300,640" data-src="//10229191.s21i.faiusr.com/95/ABUIABBfGAAg-6qZuwYouc-jlgEwuAg4sgM.webp" data-type="png" data-w="1080" src="https://10229191.s21i.faiusr.com/95/ABUIABBfGAAg-6qZuwYouc-jlgEwuAg4sgM.webp" /></section>
</section>
<p><strong>- </strong>驱动芯片的米勒钳位脚（Clamp）直接连接到SiC MOSFET的门极，米勒电流Igd（红色线）会流经Cgd→Clamp脚→T5到负电源轨，形成了一条更低阻抗的门极电荷泄放回路。</p>
<p> </p>
<p>- 驱动芯片内部比较器的翻转电压阈值为2V（参考负轨），在SiC MOSFET关断期间，当门极电压低于-2V（负轨为-4V）时，内部比较器翻转，MOSFET (T5)被打开, 使得门极以更低阻抗拉到负电源轨，从而保证SiC MOSFET达到抑制误开通的效果。</p>
<p> </p>
<p> </p>
<p><strong>04 米勒钳位作用//双脉冲平台实测对比</strong></p>
<section>
<section>
<section>
<section> </section>
</section>
</section>
<section>
<section>
<p><strong>测试条件：</strong>上管V<sub>GS</sub>=0V/+18V,下管V<sub>GS</sub>=0V；V<sub>DS</sub>=800V；I<sub>D</sub>=40A；R<sub>g</sub>=8.2Ω；L<sub>load</sub>=200uH；T<sub>a</sub>=25℃</p>
</section>
</section>
</section>
<section>
<section><img _width="100%" alt="图片" crossorigin="anonymous" data-fail="0" data-imgfileid="100021595" data-index="9" data-original-style="vertical-align:middle;width:100%;" data-ratio="0.562962962962963" data-s="300,640" data-src="//10229191.s21i.faiusr.com/95/ABUIABBfGAAg-6qZuwYozPDb0gEwuAg44AQ.webp" data-type="jpeg" data-w="1080" src="https://10229191.s21i.faiusr.com/95/ABUIABBfGAAg-6qZuwYozPDb0gEwuAg44AQ.webp" /></section>
</section>
<section>
<section>
<p>无米勒钳位</p>
</section>
</section>
<section>
<section><img _width="100%" alt="图片" crossorigin="anonymous" data-fail="0" data-imgfileid="100021596" data-index="10" data-original-style="vertical-align:middle; width:100%; pointer-events:initial;" data-ratio="0.5642023346303502" data-s="300,640" data-src="//10229191.s21i.faiusr.com/95/ABUIABBfGAAg-6qZuwYorbb0kAcwuAg44QQ.webp" data-type="jpeg" data-w="2056" src="https://10229191.s21i.faiusr.com/95/ABUIABBfGAAg-6qZuwYorbb0kAcwuAg44QQ.webp" /></section>
</section>
<section>
<section>
<p>有米勒钳位</p>
</section>
</section>
<section>
<section>
<p><strong>结论</strong></p>
</section>
</section>
<section>
<section> </section>
<section><img _width="100%" alt="图片" crossorigin="anonymous" data-fail="0" data-imgfileid="100021598" data-index="11" data-original-style="vertical-align:middle; width:100%; pointer-events:initial;" data-ratio="0.23029045643153526" data-s="300,640" data-src="//10229191.s21i.faiusr.com/95/ABUIABBfGAAg-6qZuwYo1s6mhAIwuAg4_QE.webp" data-type="jpeg" data-w="1928" src="https://10229191.s21i.faiusr.com/95/ABUIABBfGAAg-6qZuwYo1s6mhAIwuAg4_QE.webp" /></section>
</section>
<p> </p>
<section>
<section> </section>
</section>
<section>
<section>
<section>
<section> </section>
</section>
</section>
<section>
<section>
<p><strong>测试条件：</strong>上管V<sub>GS</sub>=-4V/+18V,下管V<sub>GS</sub>=-4V；V<sub>DS</sub>=800V；I<sub>D</sub>=40A；R<sub>g</sub>=8.2Ω；L<sub>load</sub>=20uH；T<sub>a</sub>=25℃</p>
</section>
</section>
</section>
<section>
<section><img _width="100%" alt="图片" crossorigin="anonymous" data-fail="0" data-imgfileid="100021600" data-index="12" data-original-style="vertical-align:middle;width:100%;" data-ratio="0.5638888888888889" data-s="300,640" data-src="//10229191.s21i.faiusr.com/95/ABUIABBfGAAg-6qZuwYowJq52QMwuAg44QQ.webp" data-type="jpeg" data-w="1080" src="https://10229191.s21i.faiusr.com/95/ABUIABBfGAAg-6qZuwYowJq52QMwuAg44QQ.webp" /></section>
</section>
<section>
<section>
<p>无米勒钳位</p>
</section>
</section>
<section>
<section> </section>
<section><img _width="100%" alt="图片" crossorigin="anonymous" data-fail="0" data-imgfileid="100021601" data-index="13" data-original-style="vertical-align:middle;width:100%;" data-ratio="0.5638888888888889" data-s="300,640" data-src="//10229191.s21i.faiusr.com/95/ABUIABBfGAAg-6qZuwYolNeN_wcwuAg44QQ.webp" data-type="jpeg" data-w="1080" src="https://10229191.s21i.faiusr.com/95/ABUIABBfGAAg-6qZuwYolNeN_wcwuAg44QQ.webp" /></section>
</section>
<section>
<section>
<p>有米勒钳位</p>
</section>
</section>
<section>
<section>
<p><strong>结论</strong></p>
</section>
</section>
<section>
<section><img _width="100%" alt="图片" crossorigin="anonymous" data-fail="0" data-imgfileid="100021599" data-index="14" data-original-style="vertical-align:middle;width:100%;" data-ratio="0.22827346465816917" data-s="300,640" data-src="//10229191.s21i.faiusr.com/95/ABUIABBfGAAg-6qZuwYoqqqeuQMw3wY4xQE.webp" data-type="jpeg" data-w="863" src="https://10229191.s21i.faiusr.com/95/ABUIABBfGAAg-6qZuwYoqqqeuQMw3wY4xQE.webp" /></section>
</section>
<p> </p>
<p> </p>
<p><strong>05 单通道带米勒钳位隔离驱动BTD5350Mx系列介绍</strong></p>
<section>
<section>
<section>
<section>
<p><strong>产品特性</strong></p>
</section>
</section>
</section>
<section>
<section>
<section> </section>
</section>
<section>
<section> </section>
</section>
<section>
<section> </section>
</section>
</section>
<section>
<section>
<section> </section>
</section>
<section>
<section> </section>
</section>
<section>
<section> </section>
</section>
</section>
<section>
<section>
<section> </section>
</section>
<section>
<section> </section>
</section>
<section>
<section> </section>
</section>
</section>
<section>
<section>
<section> </section>
</section>
<section>
<section> </section>
</section>
<section>
<section> </section>
</section>
</section>
</section>
<section>
<section>
<section>
<section>
<section>
<p> </p>
</section>
</section>
</section>
</section>
<section>
<section>
<section>
<p>专门用于驱动SiC MOSFET的门极驱动芯片</p>
</section>
</section>
</section>
</section>
<section>
<section>
<section>
<section>
<section>
<p> </p>
</section>
</section>
</section>
</section>
<section>
<section>
<section>
<p>副方驱动器带米勒钳位功能脚Clamp</p>
</section>
</section>
</section>
</section>
<section>
<section>
<section>
<section>
<section>
<p> </p>
</section>
</section>
</section>
</section>
<section>
<section>
<section>
<p>驱动器输出峰值电流可达10A</p>
</section>
</section>
</section>
</section>
<section>
<section>
<section>
<section>
<section>
<p> </p>
</section>
</section>
</section>
</section>
<section>
<section>
<section>
<p>驱动器电源全电压高达33V</p>
</section>
</section>
</section>
</section>
<section>
<section>
<section>
<section>
<section>
<p> </p>
</section>
</section>
</section>
</section>
<section>
<section>
<section>
<p>副方驱动器电源欠压保护点: 8V/11V</p>
</section>
</section>
</section>
</section>
<section>
<section>
<section>
<section>
<section>
<p> </p>
</section>
</section>
</section>
</section>
<section>
<section>
<section>
<p>封装类型: SOW-8(宽体)/SOP-8(窄体)</p>
</section>
</section>
</section>
</section>
<p> </p>
<section>
<section><img _width="100%" alt="图片" crossorigin="anonymous" data-fail="0" data-imgfileid="100021606" data-index="16" data-original-style="vertical-align:middle;width:100%;" data-ratio="0.7648148148148148" data-s="300,640" data-src="//10229191.s21i.faiusr.com/95/ABUIABBfGAAg-6qZuwYopOO48AIwuAg4ugY.webp" data-type="jpeg" data-w="1080" src="https://10229191.s21i.faiusr.com/95/ABUIABBfGAAg-6qZuwYopOO48AIwuAg4ugY.webp" /></section>
</section>
<section>
<section>
<section>
<section>
<p><strong>典型应用</strong></p>
</section>
</section>
</section>
<section>
<section>
<section> </section>
</section>
<section>
<section> </section>
</section>
<section>
<section> </section>
</section>
</section>
<section>
<section>
<section> </section>
</section>
<section>
<section> </section>
</section>
<section>
<section> </section>
</section>
</section>
<section>
<section>
<section> </section>
</section>
<section>
<section> </section>
</section>
<section>
<section> </section>
</section>
</section>
<section>
<section>
<section> </section>
</section>
<section>
<section> </section>
</section>
<section>
<section> </section>
</section>
</section>
</section>
<section>
<section>
<section>
<section>
<section>
<p> </p>
</section>
</section>
</section>
</section>
<section>
<section>
<p>工业电源</p>
</section>
</section>
</section>
<section>
<section>
<section>
<section>
<section>
<p> </p>
</section>
</section>
</section>
</section>
<section>
<section>
<section>
<p>锂电池化成设备</p>
</section>
</section>
</section>
</section>
<section>
<section>
<section>
<section>
<section>
<p> </p>
</section>
</section>
</section>
</section>
<section>
<section>
<p>商业空调</p>
</section>
</section>
</section>
<section>
<section>
<section>
<section>
<section>
<p> </p>
</section>
</section>
</section>
</section>
<section>
<section>
<p>通信电源</p>
</section>
</section>
</section>
<section>
<section>
<section>
<section>
<section>
<p> </p>
</section>
</section>
</section>
</section>
<section>
<section>
<p>光伏储能一体机</p>
</section>
</section>
</section>
<section>
<section>
<section>
<section>
<section>
<p> </p>
</section>
</section>
</section>
</section>
<section>
<section>
<p>焊机电源</p>
</section>
</section>
</section>
<p> </p>
<p><strong>06 双通道带米勒钳位隔离驱动BTD25350xx</strong></p>
<p> </p>
<section>
<section>
<section>
<section>
<section>
<section>
<p><strong>产品特性</strong></p>
</section>
</section>
</section>
<section>
<section>
<section> </section>
</section>
<section>
<section> </section>
</section>
<section>
<section> </section>
</section>
</section>
<section>
<section>
<section> </section>
</section>
<section>
<section> </section>
</section>
<section>
<section> </section>
</section>
</section>
<section>
<section>
<section> </section>
</section>
<section>
<section> </section>
</section>
<section>
<section> </section>
</section>
</section>
<section>
<section>
<section> </section>
</section>
<section>
<section> </section>
</section>
<section>
<section> </section>
</section>
</section>
</section>
<section>
<section>
<section>
<section>
<section>
<p> </p>
</section>
</section>
</section>
</section>
<section>
<section>
<section>
<p>专门用于驱动SiC MOSFET的门极驱动芯片</p>
</section>
</section>
</section>
</section>
<section>
<section>
<section>
<section>
<section>
<p> </p>
</section>
</section>
</section>
</section>
<section>
<section>
<section>
<p>原方带使能禁用脚DIS，死区时间设置脚DT</p>
</section>
</section>
</section>
</section>
<section>
<section>
<section>
<section>
<section>
<p> </p>
</section>
</section>
</section>
</section>
<section>
<section>
<section>
<p>副方驱动器带米勒钳位功能脚Clamp</p>
</section>
</section>
</section>
</section>
<section>
<section>
<section>
<section>
<section>
<p> </p>
</section>
</section>
</section>
</section>
<section>
<section>
<section>
<p>驱动器输出峰值电流可达10A</p>
</section>
</section>
</section>
</section>
<section>
<section>
<section>
<section>
<section>
<p> </p>
</section>
</section>
</section>
</section>
<section>
<section>
<section>
<p>驱动器电源全电压高达33V</p>
</section>
</section>
</section>
</section>
<section>
<section>
<section>
<section>
<section>
<p> </p>
</section>
</section>
</section>
</section>
<section>
<section>
<section>
<p>原副方封装爬电间距大于8.5mm，绝缘电压可以5000Vrms</p>
</section>
</section>
</section>
</section>
<section>
<section>
<section>
<section>
<section>
<p> </p>
</section>
</section>
</section>
</section>
<section>
<section>
<section>
<p>副方两驱动器爬电间距大于3mm，支持母线工作电压VDC=1850V</p>
</section>
</section>
</section>
</section>
<section>
<section>
<section>
<section>
<section>
<p> </p>
</section>
</section>
</section>
</section>
<section>
<section>
<section>
<p>副方驱动器电源欠压保护点：8V/11V</p>
</section>
</section>
</section>
</section>
<section>
<section>
<section>
<section>
<section>
<p> </p>
</section>
</section>
</section>
</section>
<section>
<section>
<section>
<p>封装类型: SOW-18</p>
</section>
</section>
</section>
</section>
</section>
</section>
<p><img _width="100%" alt="图片" crossorigin="anonymous" data-fail="0" data-imgfileid="100021604" data-index="18" data-original-style="vertical-align:middle;width:100%;" data-ratio="0.5370370370370371" data-s="300,640" data-src="//10229191.s21i.faiusr.com/95/ABUIABBfGAAg-6qZuwYo64CtywcwuAg4xAQ.webp" data-type="jpeg" data-w="1080" src="https://10229191.s21i.faiusr.com/95/ABUIABBfGAAg-6qZuwYo64CtywcwuAg4xAQ.webp" /></p>
<section>
<p> </p>
<section>
<section>
<section>
<section>
<section>
<section>
<p><strong><strong>应用方向</strong></strong></p>
</section>
</section>
</section>
<section>
<section>
<section> </section>
</section>
<section>
<section> </section>
</section>
<section>
<section> </section>
</section>
</section>
<section>
<section>
<section> </section>
</section>
<section>
<section> </section>
</section>
<section>
<section> </section>
</section>
</section>
<section>
<section>
<section> </section>
</section>
<section>
<section> </section>
</section>
<section>
<section> </section>
</section>
</section>
<section>
<section>
<section> </section>
</section>
<section>
<section> </section>
</section>
<section>
<section> </section>
</section>
</section>
</section>
<section>
<section>
<section>
<section>
<section>
<p> </p>
</section>
</section>
</section>
</section>
<section>
<section>
<p>充电桩中后级LLC用SiC MOSFET 方案</p>
</section>
</section>
</section>
<section>
<section>
<section>
<section>
<section>
<p> </p>
</section>
</section>
</section>
</section>
<section>
<section>
<section>
<p>光伏储能BUCK-BOOST中SiC MOSFET方案</p>
</section>
</section>
</section>
</section>
<section>
<section>
<section>
<section>
<section>
<p> </p>
</section>
</section>
</section>
</section>
<section>
<section>
<p>高频APF，用两电平的三相全桥SiC MOSFET方案</p>
</section>
</section>
</section>
<section>
<section>
<section>
<section>
<section>
<p> </p>
</section>
</section>
</section>
</section>
<section>
<section>
<p>空调压缩机三相全桥SiC MOSFET方案</p>
</section>
</section>
</section>
<section>
<section>
<section>
<section>
<section>
<p> </p>
</section>
</section>
</section>
</section>
<section>
<section>
<p>OBC后级LLC中的SiC MOSFET方案</p>
</section>
</section>
</section>
<section>
<section>
<section>
<section>
<section>
<p> </p>
</section>
</section>
</section>
</section>
<section>
<section>
<p>服务器交流侧图腾柱PFC高频臂GaN或者SiC方案</p>
</section>
</section>
</section>
</section>
</section>
</section>
</section>
<div></div>
<div></div>
<p>为了保持电力电子系统竞争优势，同时也为了使最终用户获得经济效益，一定程度的效率和紧凑性成为每一种电力电子应用功率转换应用的优势所在。随着IGBT技术到达发展瓶颈，加上SiC MOSFET绝对成本持续下降，使用SiC MOSFET单管及模块替代升级IGBT单管及模块已经成为各类型电力电子应用的主流趋势。</p>
<p>学习汇川技术，咬住必然，勇立潮头！国产SiC碳化硅MOSFET功率器件一级代理商倾佳电子杨茜咬住三个必然，勇立功率器件变革潮头：</p>
<p>国产SiC碳化硅MOSFET功率器件一级代理商倾佳电子杨茜咬住SiC碳化硅MOSFET模块革掉IGBT模块的必然趋势！</p>
<p>国产SiC碳化硅MOSFET功率器件一级代理商倾佳电子杨茜咬住SiC碳化硅MOSFET单管革掉IGBT单管的必然趋势！</p>
<p>国产SiC碳化硅MOSFET功率器件一级代理商倾佳电子杨茜咬住650V SiC碳化硅MOSFET单管革掉SJ超结MOSFET的必然趋势！</p>
<p>IGBT芯片技术不断发展，但是从一代芯片到下一代芯片获得的改进幅度越来越小。这表明IGBT每一代新芯片都越来越接近材料本身的物理极限。SiC MOSFET宽禁带半导体提供了实现半导体总功率损耗的显著降低的可能性。使用SiC MOSFET可以降低开关损耗，从而提高开关频率。进一步的，可以优化滤波器组件，相应的损耗会下降，从而全面减少系统损耗。通过采用低电感SiC MOSFET功率模块，与同样封装的Si IGBT模块相比，功率损耗可以降低约70%左右，可以将开关频率提5倍（实现显著的滤波器优化），同时保持最高结温低于最大规定值。<br />
<br />
未来随着设备和工艺能力的推进，更小的元胞尺寸、更低的比导通电阻、更低的开关损耗、更好的栅氧保护是SiC碳化硅MOSFET技术的主要发展方向，体现在应用端上则是更好的性能和更高的可靠性。<br />
为此，BASiC™基本公司研发推出更高性能的第三代碳化硅MOSFET，该系列产品进一步优化钝化层，提升可靠性，相比上一代产品拥有更低比导通电阻、器件开关损耗，以及更高可靠性等优越性能，可助力光伏储能、新能源汽车、直流快充、工业电源、通信电源、伺服驱动、APF/SVG、热泵驱动、工业变频器、逆变焊机、四象限工业变频器等行业实现更为出色的能源效率和应用可靠性。</p>
页:
[1]