High-power and high-reliability GaN/InGaN flip-chip light-emitting diodes （FCLEDs） have been demonstrated by employing a flip-chip design, and its fabrication process is developed. FCLED is composed of a LED die and...High-power and high-reliability GaN/InGaN flip-chip light-emitting diodes （FCLEDs） have been demonstrated by employing a flip-chip design, and its fabrication process is developed. FCLED is composed of a LED die and a submount which is integrated with circuits to protect the LED from electrostatic discharge （ESD） damage. The LED die is flip-chip soldered to the submount, and light is extracted through the transparent sapphire substrate instead of an absorbing Ni/Au contact layer as in conventional GaN/InGaN LED epitaxial designs. The optical and electrical characteristics of the FCLED are presented. According to ESD IEC61000-4-2 standard （human body model）, the FCLEDs tolerated at least 10 kV ESD shock have ten times more capacity than conventional GaN/InGaN LEDs. It is shown that the light output from the FCLEDs at forward current 350mA with a forward voltage of 3.3 V is 144.68 mW, and 236.59 mW at 1.0A of forward current. With employing an optimized contact scheme the FCLEDs can easily operate up to 1.0A without significant power degradation or failure. The li.fe test of FCLEDs is performed at forward current of 200 mA at room temperature. The degradation of the light output power is no more than 9% after 1010.75 h of life test, indicating the excellent reliability. FCLEDs can be used in practice where high power and high reliability are necessary, and allow designs with a reduced number of LEDs.展开更多
电源管理芯片在超过可承受温度范围工作时会对自身造成不同程度的损坏,过温保护电路对提高该类芯片的可靠性和鲁棒性具有重要作用。文中设计了一种具有温度过高关断和温度过低提醒等双重功能的高精度过温保护电路。利用正、负温度系数...电源管理芯片在超过可承受温度范围工作时会对自身造成不同程度的损坏,过温保护电路对提高该类芯片的可靠性和鲁棒性具有重要作用。文中设计了一种具有温度过高关断和温度过低提醒等双重功能的高精度过温保护电路。利用正、负温度系数电压对芯片温度进行实时检测,并与带隙基准电路输出端的不同基准电压分别进行比较得到4个逻辑翻转点,进而通过高精度比较器电路和迟滞逻辑电路处理后,输出迟滞逻辑信号来控制芯片的工作状态或进行温度过低提醒。基于0.18μm BCD(Bipolar-Complementary Metal Oxied Semiconductor-Double diffused Metal Oxide Semiconductor)工艺设计并完成了相关仿真验证,仿真结果表明,在电源电压范围为3.0~5.5 V时,该电路输出端的迟滞逻辑翻转信号对应的温度阈值最大偏移量在0.3℃以内,具备较高的精度,可广泛集成于各种需要过温保护功能的电源管理芯片。展开更多
高功率880nm激光芯片的结构设计,均采用大光学腔和小于0.62cm-1的低内损,并通过MOCVD(Metal-organic Chemical Vapor Deposition)工艺实现这种结构的外延。通过一系列标准和特殊制造工艺,实现了200μm发射器宽度和4mm腔长激光芯片。在P...高功率880nm激光芯片的结构设计,均采用大光学腔和小于0.62cm-1的低内损,并通过MOCVD(Metal-organic Chemical Vapor Deposition)工艺实现这种结构的外延。通过一系列标准和特殊制造工艺,实现了200μm发射器宽度和4mm腔长激光芯片。在P面朝下贴装在AlN陶瓷基板上后,测试880nm激光器的阈值电流为1.1A,斜率效率为1.11W/A,中心工作波长为11A时为880.8nm,光谱半高宽(FWHM)为2.2nm。在16A的连续电流和20°C的冷却水温下进行加速老化试验,老化时间达到2000h时无故障。根据ISO/FDIS 17526的Arrhenius模型,MTTF(Mean time to failure)计算为20万小时。展开更多
This paper uses CT to gain the energy directly from the high-voltage transmission line, to address the problem of power supply for monitoring system in high voltage side of transmission line. The draw-out power coil c...This paper uses CT to gain the energy directly from the high-voltage transmission line, to address the problem of power supply for monitoring system in high voltage side of transmission line. The draw-out power coil can induce voltage from the transmission line, using single-chip microcomputer to analog and output PMW wave to control the charging module, provides a stable 3.4 V DC voltage to the load, and solve the problem of easy saturating of core. The power supply based on this kind of draw-out power coil has undergone the overall testing, and it is verified-showing that it can properly work in a non-saturated status within the current range of 50 - 1000 A, and provide a stable output. The equipment also design protection circuit to improve the reliability to avid the impacts of the impulse current or short-circuit current. It effectively solves the problem of power supply for On-line Monitoring System of Transmission.展开更多
Electron cyclotron resonance heating (ECRH) system is one of the most important Tokamak auxiliary heating methods. However, there are growing demands for ECRH system as the physical experiments progress which meanwhil...Electron cyclotron resonance heating (ECRH) system is one of the most important Tokamak auxiliary heating methods. However, there are growing demands for ECRH system as the physical experiments progress which meanwhile adds the difficulty of designing and building the control system of its power source. In this paper, the method of designing a control system based on Single Chip Microcomputer (SCM) and Field Programmable Gate Array (FPGA) is introduced according to its main requirements. The experimental results show that the control system in this paper achieves the conversion of different working modes, gets exact timing, and realizes the failure protection in 10us thus can be used in the ECRH system.展开更多
文摘High-power and high-reliability GaN/InGaN flip-chip light-emitting diodes （FCLEDs） have been demonstrated by employing a flip-chip design, and its fabrication process is developed. FCLED is composed of a LED die and a submount which is integrated with circuits to protect the LED from electrostatic discharge （ESD） damage. The LED die is flip-chip soldered to the submount, and light is extracted through the transparent sapphire substrate instead of an absorbing Ni/Au contact layer as in conventional GaN/InGaN LED epitaxial designs. The optical and electrical characteristics of the FCLED are presented. According to ESD IEC61000-4-2 standard （human body model）, the FCLEDs tolerated at least 10 kV ESD shock have ten times more capacity than conventional GaN/InGaN LEDs. It is shown that the light output from the FCLEDs at forward current 350mA with a forward voltage of 3.3 V is 144.68 mW, and 236.59 mW at 1.0A of forward current. With employing an optimized contact scheme the FCLEDs can easily operate up to 1.0A without significant power degradation or failure. The li.fe test of FCLEDs is performed at forward current of 200 mA at room temperature. The degradation of the light output power is no more than 9% after 1010.75 h of life test, indicating the excellent reliability. FCLEDs can be used in practice where high power and high reliability are necessary, and allow designs with a reduced number of LEDs.
文摘电源管理芯片在超过可承受温度范围工作时会对自身造成不同程度的损坏,过温保护电路对提高该类芯片的可靠性和鲁棒性具有重要作用。文中设计了一种具有温度过高关断和温度过低提醒等双重功能的高精度过温保护电路。利用正、负温度系数电压对芯片温度进行实时检测,并与带隙基准电路输出端的不同基准电压分别进行比较得到4个逻辑翻转点,进而通过高精度比较器电路和迟滞逻辑电路处理后,输出迟滞逻辑信号来控制芯片的工作状态或进行温度过低提醒。基于0.18μm BCD(Bipolar-Complementary Metal Oxied Semiconductor-Double diffused Metal Oxide Semiconductor)工艺设计并完成了相关仿真验证,仿真结果表明,在电源电压范围为3.0~5.5 V时,该电路输出端的迟滞逻辑翻转信号对应的温度阈值最大偏移量在0.3℃以内,具备较高的精度,可广泛集成于各种需要过温保护功能的电源管理芯片。
文摘高功率880nm激光芯片的结构设计,均采用大光学腔和小于0.62cm-1的低内损,并通过MOCVD(Metal-organic Chemical Vapor Deposition)工艺实现这种结构的外延。通过一系列标准和特殊制造工艺,实现了200μm发射器宽度和4mm腔长激光芯片。在P面朝下贴装在AlN陶瓷基板上后,测试880nm激光器的阈值电流为1.1A,斜率效率为1.11W/A,中心工作波长为11A时为880.8nm,光谱半高宽(FWHM)为2.2nm。在16A的连续电流和20°C的冷却水温下进行加速老化试验,老化时间达到2000h时无故障。根据ISO/FDIS 17526的Arrhenius模型,MTTF(Mean time to failure)计算为20万小时。
文摘This paper uses CT to gain the energy directly from the high-voltage transmission line, to address the problem of power supply for monitoring system in high voltage side of transmission line. The draw-out power coil can induce voltage from the transmission line, using single-chip microcomputer to analog and output PMW wave to control the charging module, provides a stable 3.4 V DC voltage to the load, and solve the problem of easy saturating of core. The power supply based on this kind of draw-out power coil has undergone the overall testing, and it is verified-showing that it can properly work in a non-saturated status within the current range of 50 - 1000 A, and provide a stable output. The equipment also design protection circuit to improve the reliability to avid the impacts of the impulse current or short-circuit current. It effectively solves the problem of power supply for On-line Monitoring System of Transmission.
文摘Electron cyclotron resonance heating (ECRH) system is one of the most important Tokamak auxiliary heating methods. However, there are growing demands for ECRH system as the physical experiments progress which meanwhile adds the difficulty of designing and building the control system of its power source. In this paper, the method of designing a control system based on Single Chip Microcomputer (SCM) and Field Programmable Gate Array (FPGA) is introduced according to its main requirements. The experimental results show that the control system in this paper achieves the conversion of different working modes, gets exact timing, and realizes the failure protection in 10us thus can be used in the ECRH system.
