氮化镓功率晶体管应用技术研究

发布时间：2018-07-06 09:27

本文选题：氮化镓 + 反向导通　；参考：《南京航空航天大学》2015年硕士论文

【摘要】：硅(Si)功率器件发展至今已接近其性能极限,难以满足开关电源高频、高效率、高功率密度的需求。氮化镓(Ga N)功率晶体管作为宽禁带半导体材料的典型代表,因其开关速度快、寄生参数小、电气参数优越而受到广泛关注。近年来多家半导体厂商已相继推出Ga N器件,因此,开展氮化镓功率晶体管的应用研究工作显得十分迫切。本文首先分析了低压和高压Ga N功率晶体管的性能优势与不足。低压增强型Ga N晶体管体积小、寄生参数小等优势适宜高频工作;但其反向导通压降高、驱动电压范围窄。高压耗尽型Ga N晶体管驱动技术简单,反向恢复特性优异,但其难以实现真正意义的ZVS,这一定程度限制了工作频率的提高。在特性分析的基础上,针对低压Ga N晶体管反向导通压降高、驱动电压范围窄的不足,本文提出一种适用于低压Ga N晶体管的改进型三电平驱动方式,该方式通过合理设置死区时间并利用假性开通原理,减小了反向导通损耗、抑制了驱动电压的振荡。一台12V输入、1.2V/20A输出、1MHz开关频率的原理样机验证了所提方案的可行性。对高压Ga N功率晶体管,本文通过对比实验验证了封装寄生参数对高频工作性能的影响,得出了表贴式封装适宜高频工作的结论。论文指出了高压Ga N功率晶体管结电容小有利于减小LLC谐振变换器死区时间,从而优化关断损耗和导通损耗,提高变换器效率。实验室制作完成了400V输入、12V/25A输出、1MHz开关频率的原理样机并与Si MOSFET进行了对比实验,结果表明Ga N器件的高频开关性能和效率优势明显。
[Abstract]:Silicon (Si) power devices have been developed close to their performance limits, and it is difficult to meet the needs of high frequency, high efficiency and high power density of switching power supply. Gallium nitride (gan) power transistors, as typical representatives of wide band gap semiconductor materials, have attracted wide attention due to their high switching speed, small parasitic parameters and superior electrical parameters. In recent years, many semiconductor manufacturers have introduced gan devices one after another, so it is very urgent to research the application of Gallium nitride power transistors. Firstly, the performance advantages and disadvantages of low voltage and high voltage gan power transistors are analyzed. The low voltage enhanced gan transistor has the advantages of small volume and small parasitic parameters, but its reverse on-voltage drop is high and its driving voltage range is narrow. The drive technology of high voltage depleted gan transistor is simple and the reverse recovery characteristic is excellent, but it is difficult to realize the true meaning of ZVS, which limits the increase of working frequency to a certain extent. On the basis of characteristic analysis, an improved three-level drive mode for low-voltage gan transistors is proposed in this paper, aiming at the shortcomings of high reverse on-voltage drop and narrow driving voltage range of low-voltage gan transistors. By setting the dead time reasonably and using the false turn-on principle, the reverse conduction loss is reduced and the oscillation of the driving voltage is restrained. A 12V input 1.2V / 20A output 1MHz switching frequency prototype verifies the feasibility of the proposed scheme. For high voltage gan power transistors, the effect of parasitic parameters on the performance of high frequency is verified by comparison experiments, and the conclusion is drawn that the package is suitable for high frequency operation. In this paper, it is pointed out that the small capacitor of high voltage gan power transistor junction is beneficial to reduce the dead time of LLC resonant converter, thus optimize the turn-off loss and on-loss, and improve the efficiency of the converter. A 400V input 12V / 25A output 1MHz switching frequency prototype has been fabricated and compared with that of Si MOSFET. The results show that the high frequency switching performance and efficiency advantages of gan devices are obvious.
【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN323.4

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