基于肖特基栅共振隧穿三极管的器件模拟与实验分析

通过流片,制作出肖特基栅共振隧穿三极管(SGRTT).根据ATLAS软件的模拟发现,当发射极接地, 集电极接外加偏压时,栅极电压对于SGRTT的电流起到明显的控制作用.当集电极接地,栅极电压会主要影响峰值电压,其原因是栅极电压和发射极、集电极的电场分布将会改变耗尽区的分布.实验测试结果对这种现象也予以证实.     

采用低损耗IGBT为次级2.5kW逆变器应用提升开关性能

传统的lGBT(绝缘栅极型功率管)通常应用在要求高电压和高电流等级,以及相对缓慢的开关频率的场合.当开关频率低时,IGBT固有的低传导损耗源自IGBT中少数载流子工作产生的低VCE(on)(集电极-发射极饱和电压),其在价值上已经超过了它贫乏的开关性能,使获得高的整体操作效率成为可能.     

影响IGBT驱动电路性能参数的因素分析

分析了桥式电路中IGBT的动态开关过程以及IGBT的栅极、发射极和集电极的分布电感与其他分布参数的综合作用对IGBT驱动电路的影响,并且通过实验验证了理论分析的正确性,最后指出了IGBT驱动电路设计时的注意事项。     

稳压电源过压自动切断电路

稳压电源在工作过程中,有时调整管发射极、集电极间被击穿,引起输出电压增高,造成负载不能正常工作,以致损坏元器件.此时即使有过流保护电路也不一定起作用. 对于比较昂贵的电子产品,如微处理机等的电源,稳压电路有必要采用过压保护电路.当调整管发射极、集电极间被击穿,成因其他原因引起输出电压增高时,保护电路动作,能自动切断电源,起到保护电源负载的作用.     

电子线路学习方法(十一) 第五讲 三极管电路分析方法(上)

<正> 一、三极管电路等效理解方法三极管有三个引脚,在进行电阻等效理解时主要等效集电极与发射极之间的内阻,其他引脚之间的等效分析比较少。1.集电极与发射极之间内阻等效电路方法分析一些三极管控制电路中,需要将三极管集电极与发射极之间的内阻进行等效,如图1所示是三极管三种工作状态下的集电极与发射极之间内阻等效电路。(1)截止状态下等效电路。当三极管截止时,它的集电极与发射极之间内阻很大,许多电路分析中可以认为三极管集电极与发射极之间为开路状态。     

晶体管的特性显示(下)

(四)转移特性共发射极组态的电流转移特性定义为集电极电压恒定时,集电极电流与基极电流之间的关系曲线.显示原理方框图见图10.锯齿电压经大电阻R_(62)变成锯齿电流加到被测管的基极,集电极电流由串入发射极电路中的电阻R_(68)上取得.转移特性亦采用单条显示.被测管集电极电压由电位器W_2改变,电压     

无偏置源的多谐振荡器

普通等待式的多谐振荡器,为保持其中一个晶体管截止,要求有偏置电压(图a).在晶体管BG_1的基极接一个二极管D_1,可不用偏置源(图b).当电路处于静态时,供给BG_1基极电流唯一的电压是导通管BG_2的集电极-发射极饱和电压.这电压为激起通过BG_1的基极的电流是太小了,因BG_1的基极-发射极     

金星、福日37厘米彩电基板放电故障二例

故障现象:一台福日14英寸彩电,开机后满屏红光;一台金星14英寸彩电,开机后满屏绿光,均伴有回归线,初判是某一视放管集电极电压过低导致相应的阴极电流过大造成的。测试各视放管的各极直流电压,发现基极、发射极电压均正常,而满屏红光(或绿光)的红色(或绿色)视放管集电极电压低至40V左右(正常约148V)。用万用表“×1kΩ”档测视放管集电极对地电阻(红表笔接地),阻值仅1～2kΩ     

IGBT关断瞬态电压尖峰影响及抑制

绝缘栅双极晶体管(IGBT)是一种性能优良的全控型电力电子器件,由于线路和器件内部分布电感的存在,关断时集电极电流的快速变化会感应产生一个较大的电压尖峰从而引起过电压击穿。分析了栅极结电容放电时间常数和拖尾电流对电压尖峰的影响,通过改变栅极驱动电阻和温度可以抑制电压尖峰。分析了电压尖峰引起过压击穿的失效机理以及失效模式,表明IGBT过压击穿引起失效的本质仍然是结温过高引起的热击穿失效。     

电子线路学习方法(十六) 第八讲 单级放大器电路分析方法(上)

一、三极管的信号传输如图1所示是共发射极放大器输入信号回路和输出信号回路示意图,当三极管有基极电流后便有了集电极电流和发射极电流.从图中可以看出,共发射极放大器中,三极管三个电极中输入回路和输出回路共用了发射极,共发射极放大器名称由此而来.正是由于有了基极电流,同时有了集电极和发射极电流,这说明加到三极管基极回路的信号...     

DC I-V characteristics of field emitter triodes

A simple model that is applicable to Spindt-type emitter triodes is presented. Experimentally, it has been observed that the gate current at zero collector voltage follows the same Fowler-Nordheim law as the collector current at high collector voltage, and that for low emission current densities, the sum of gate and collector currents is constant for any collector voltage and is given by the Fowler-Nordheim current I_FN. Based on these observations, a simple model has been developed to calculate the I-V characteristics of a triode. By measuring the Fowler-Nordheim emission, emission area and field enhancement can be obtained assuming a value for the barrier height. Incorporating the gate current, the collector current can be calculated from I_c=I_FN-I_g as a function of collector voltage. The model's accuracy is best at low current density. At higher emission currents, deviations occur at low collector voltages because the constancy of gate and collector currents is violated     

An IGBT Gate Driver for Feed-Forward Control of Turn-on Losses and Reverse Recovery Current

This paper addresses the problem of turn on performances of an insulated gate bipolar transistor (IGBT) that works in hard switching conditions. The IGBT turn on dynamics with an inductive load is described, and corresponding IGBT turn on losses and reverse recovery current of the associated freewheeling diode are analysed. A new IGBT gate driver based on feed-forward control of the gate emitter voltage is presented in the paper. In contrast to the widely used conventional gate drivers, which have no capability for switching dynamics optimisation, the proposed gate driver provides robust and simple control and optimization of the reverse recovery current and turn on losses. The collector current slope and reverse recovery current are controlled by means of the gate emitter voltage control in feed-forward manner. In addition the collector emitter voltage slope is controlled during the voltage falling phase by means of inherent increase of the gate current. Therefore, the collector emitter voltage tail and the total turn on losses are significantly reduced. The proposed gate driver was experimentally verified and compared to a conventional gate driver, and the results are presented and discussed in the paper.     

双极场引晶体管:III.短沟道电化电流理论（双MOS栅纯基）

本文描述双极场引晶体管(BiFET)短沟道理论. 晶体管分成两个区域,源区和漏区. 每区在特定外加端电压下既可为电子或空穴发射区又可为电子或空穴收集区. 把两维无缺陷Shockley方程分离为两个以表面势为参变量的一维方程,并运用源区和漏区界面处电子电流和空穴电流连续性,得到在源区和漏区内解析方程. 典型BiFET包括薄纯基上两个等同金属氧化物硅（MOS）栅. 用图形提供实用硅基和氧化层厚度范围内,随直流电压变化,输出和转移电流和电导总量,电子沟道与空穴沟道分量,和两区电学长度.报道前没考虑沟道缩短的偏差。     

双极场引晶体管:Ⅲ.短沟道电化电流理论(双MOS栅纯基)

本文描述双极场引晶体管(BiFET)短沟道理论.晶体管分成两个区域,源区和漏区.每区在特定外加端电压下既可为电子或空穴发射区又可为电子或空穴收集区.把两维无缺陷Shockley方程分离为两个以表面势为参变量的一维方程,并运用源区和漏区界面处电子电流和空穴电流连续性,得到在源区和漏区内解析方程.典型BiFET包括薄纯基上两个等同金属氧化物硅(MOS)栅.用图形提供实用硅基和氧化层厚度范围内,随直流电压变化,输出和转移电流和电导总量,电子沟道与空穴沟道分量,和两区电学长度.报道前没考虑沟道缩短的偏差.     

Opposite-polarity voltage generator by hole impact ionization in asilicon bipolar transistor

A single n-p-n transistor was used to generate a negative voltage at the collector terminal when a positive voltage was applied to the emitter relative to its grounded base. It is believed that this effect was a result of hole impact ionization at field E≃0 at the band-edge energy maximum in the base-collector junction, and some of the electrons so created diffused and drifted to the collector, thus accounting for the otherwise unexpected negative collector potential. Possible applications of this effect are given     

Transient analysis of stored charge in neutral base region

The authors studied the transient relationship between stored charge in the neutral base region and electron current flowing through emitter and collector terminals. Stored charge flows not only through an emitter terminal but also through a collector terminal when emitter-base junction voltage decreases from the switch-on voltage to zero. The ratio of net charge flowing through the emitter terminal to that flowing through the collector terminal is 2:1 once a steady state has been reached. No charge accumulates through the collector terminal when the emitter-base junction voltage increases from zero to the switch-on voltage, however, so the charge partition ratio depends on the sign of the time gradient of the emitter-base voltage     

双极场引晶体管:Ⅳ.短沟道飘移扩散理论(双MOS栅纯基)

本文描述双极场引晶体管(BiFET)短沟道解析理论,用解析理论分别计算飘移扩散电流.上月文章用单项电化电流描述飘移扩散电流.正如那篇文章里,两维晶体管分成两个区域,源区和漏区.每区在特定外加端电压下既可为电子或空穴发射区又可为电子或空穴收集区.把两维无缺陷Shockley方程分离为两个以表面势为参变量的一维方程,并运用源区和漏区界面处电子电流和空穴电流连续性,得到在源区和漏区内解析方程.典型BiFET包括薄纯基上两个等同金属氧化物硅(MOS)栅.用图形提供实用硅基和氧化层厚度范围内,随直流电压变化,输出和转移电流和电导总量,电子沟道与空穴沟道飘移扩散分量,和两区电学长度.描述两区短沟道理论相对一区长沟道理论偏差.     

双极场引晶体管:IV.短沟道飘移扩散理论（双MOS栅纯基）

本文描述双极场引晶体管(BiFET)短沟道解析理论,用解析理论分别计算飘移扩散电流.上月文章用单项电化电流描述飘移扩散电流.正如那篇文章里,两维晶体管分成两个区域,源区和漏区.每区在特定外加端电压下既可为电子或空穴发射区又可为电子或空穴收集区.把两维无缺陷Shockley方程分离为两个以表面势为参变量的一维方程,并运用源区和漏区界面处电子电流和空穴电流连续性,得到在源区和漏区内解析方程.典型BiFET包括薄纯基上两个等同金属氧化物硅(MOS)栅.用图形提供实用硅基和氧化层厚度范围内,随直流电压变化,输出和转移电流和电导总量,电子沟道与空穴沟道飘移扩散分量,和两区电学长度.描述两区短沟道理论相对一区长沟道理论偏差.     

Experimental demonstration and theory of a corrective to second breakdown in Si power transistors

This paper reports experimental measurements on second breakdown behavior of transistors which were altered from conventional structure so as to allow the addition of externally mounted, variable resistors to a finely divided emitter. It is found that forward-biased second breakdown can be improved so that with suitable resistances, the safepower vs. voltage curve becomes a straight line, allowing the transistor power dissipation to be thermally limited at all voltages rather than second break limited at higher voltages. Data are presented showing the variation of obtainable power and the degree of nonuniform current distribution as a function of the resistance in series with the divided emitter. The significance of the extent of emitter subdivision, i.e., how small the discrete areas are, is also shown by data taken using the emitter sites individually and in clusters. The theory supporting these experiments is presented. What is essentially required is a load line analysis applied simultaneously to the various IEvs. VBEcurves of the individual emitter regions. This is complicated by the shifting of these curves both with temperature and the application of collector voltage.